A few of you may remember espeak-gui, a graphical user interface for eSpeak I did release two years ago. While I haven t been dedicating much time to it, it s still alive and I m happy to announce its fourth release! This new release introduced automatic language guessing, a feature I ve wanted for a while, as well as spell checking (contributed by Joe Burmeister). Version 0.3, released a year ago and which I didn t announce here, did also introduce Undo/Redo, pausing, file history logging, a bunch of translations and some voice options. It s sister project, python-espeak, did also get some bug fixes since its first release. As usual, packages for both espeak-gui and python-espeak are available in my PPA, and since last month in Debian unstable. Make sure you also install libtextcat0 (version 2.2-8 or newer) to get the language identification support. Related posts:

1. espeak-gui 0.2 Yesterday I did a first release of espeak-gui, so while...
2. Introducing espeak-gui I m joining the hype of presenting little new projects there...
3. Here is Zeitgeist 0.2.1! One month after the first Zeitgeist release (0.2), here is...

As many would know, Debian GNU/Linux is one of the oldest, and the largest Linux distributions that is available for free. Since it was first released in 1993, several people have analysed the size and produced cost estimates for the project. In 2001, Jes s M. Gonz lez-Barahona et al produced an article entitled Counting Potatoes , an analysis of Debian 2.2 (code named Potato). When Potato was released in June 2003, it contained 2,800 source packages of software, totalling around 55 million lines of source code. When using David A. Wheeler s sloccount tool to apply the COCOMO model of development, and an average developer salary of US$56,000, the projected development cost that Gonz lez-Barahona calculated to start-from-scratch and build Debian 2.2 in 2003 was US$1.9 billion. In 2007 an analysis entitled Macro-level software evolution: a case study of a large software compilation by Jes s M. Gonz lez-Barahona, Gregorio Robles, Martin Michlmayr, Juan Jos Amor and Daniel M. German was released. It found that Debian 4.0 (codename Etch released April 2007) had just over 10,000 source packages of software and 288 million lines of source code. This analysis also delved into the dependencies of software packages, and the update flow between Debian release (not all packages are updated with each release). Today (February 2012) the current development version of Debian, codenamed Wheezy, contains some 17,141 source packages of software, but as it s still in development this number may change over the coming months. I analysied the source code in Wheezy, looking at the content from the original software that Debian distributes from its upstream authors without including the additional patches that Debian Developers apply to this software, or the package management scripts (used to install, configure and de-install packages). One might argue that these patches and configuration scripts are the added value of Debian, however the in my analysis I only examined the pristine upstream source code. By using David A Wheeler s sloccount tool and average wage of a developer of US$72,533 (using median estimates from Salary.com and PayScale.com for 2011) I summed the individual results to find a total of 419,776,604 source lines of code for the pristine upstream sources, in 31 programming languages including 429 lines of Cobol and 1933 lines of Modula3! In my analysis the projected cost of producing Debian Wheezy in February 2012 is US$19,070,177,727 (AU$17.7B, EUR 14.4B, GBP 12.11B), making each package s upstream source code wrth an average of US$1,112,547.56 (AU$837K) to produce. Impressively, this is all free (of cost). Zooming in on the Linux Kernel In 2004 David A. Wheeler did a cost analysis of the Linux Kernel project by itself. He found 4,000,000 source lines of code (SLOC), and a projected cost between US$175M and US$611M depending on the complexity rating of the software. Within my analysis above, I used the standard (default) complexity with the adjusted salary for 2011 (US$72K), and deducted that Kernel version 3.1.8 with almost 10,000,000 lines of source code would be worth US$540M at standard complexity, or US$1,877M when rated as complex . Another Kernel Costing in 2011 put this figure at US$3 billion, so perhaps there s some more variance in here to play with. Individual Projects Other highlights by project included:

Project	Version	Thousands of SLOC	Projected cost at US$72,533/developer/year
Samba	3.6.1	2,000	US$101 (AU$93M)
Apache	2.2.9	693	US$33.5M (AU$31M)
MySQL	5.5.17	1,200	US$64.2M (AU$59.7M)
Perl	5.14.2	669	US$32.3M (AU$30M)
PHP	5.3.9	693	US$33.5M (AU$31.1M)
Bind	9.7.3	319	US$14.8M (AU$13.8M)
Moodle	1.9.9	396	US$18.6M (AU$17.3M)
Dasher	4.11	109	US$4.8M (AU$4.4M)
DVSwitch	0.8.3.6	6	US$250K (AU$232K)

Debian Wheezy by Programming Language The upstream code that Debian distributes is written in many different languages. ANSI C with 168,536,758 is the dominant language (40% of all lines), followed by C++ at 83,187,329 (20%) and Java with 34,698,990 (8%). If you are intersted in finding the line count and cost projections for any of the 17,000+ projects, you will find them in the raw data CSV. Other Tools and Comparisons Ohcount is another source code cost analysis tool. In March 2011 Ohcount was run across Debian Sid: its results are here. In comparison, its results appear much lower than the sloccount tool. There s also the Ohloh.net Debian Estimate which only finds 55 Million source lines of code and a projected cost of US$1B. However Ohloh uses Ohcount for its estimates, and seems to be to be around 370 million SLOC missing compared to my recent analysis. Summary Over the last 10 years the cost to develop Debian has increased ten-fold. It s intersting to know that US$19 billion of software is available to use, review, extend, and share, for the bargain price of $0. If we were to add in Debian patches and install scripts then this projected figure would increase. If only more organisations would realise the potential they have before them. Need help with Linux (including Debian), Perl, or AWS? See www.jamesbromberger.com.

I'm working on porting FreeGLUT to Android! Since I don't have access so the repository (I'm not a regular contributor), and since it will be a BIG patch, I thought I'd try a git-svn branch. So this won't be a post on OpenGL for once I'm not an expert at managing Git branch but here's how I set it up. In this case, let's forget about importing tags: they don't have the same directory branch point in the hierarchy (sometimes the freeglut/ module, sometimes the parent directory), and git-svn only correctly supports set of sane tags that track the same initial directory. SVN is SLOW, especially remotely. I suggest you make a rsync copy of the repository first, it will greatly speed up the import :

rsync -avHSP freeglut.svn.sourceforge.net::svn/freeglut/ freeglut.svn/

Then start the import with git-svn :

git svn clone --trunk=trunk/freeglut/freeglut file://$(pwd)/freeglut.svn/ freeglut-git/

And edit .git/config to point to https://freeglut.svn.sourceforge.net/svnroot/freeglut :

[svn-remote "svn"]
    url = https://freeglut.svn.sourceforge.net/svnroot/freeglut
    fetch = trunk/freeglut/freeglut:refs/remotes/trunk

I work with 2 branches:

• master : the SVN on-going sync - may be rebased to push with git svn dcommit
• android : my feature branch - not rebased and hence trackable by contributors

Here's how I synchronize the upstream repository and merge it regularly with my feature branch:

git svn fetch
git checkout master
git merge remotes/trunk
git checkout android  # my feature branch
git merge master
# if conflict
git add .../sthing.c
git commit -m "Merge master"
git push

Any better way? The ongoing work is available at https://gitorious.org/freeglut/android

Talking about Secure Boot again, I'm afraid. One of the things that's made discussion of this difficult is that, while the specification isn't overly complicated, some of the outcomes aren't obvious at all until you spend a long time thinking about it. So here's some clarification on a few points.
Secure Boot provides no additional securityUntrue. Attacks against the pre-boot environment are real and increasingly common - this is a recent proof of concept, and this has been seen in the wild. Once something has got into the MBR, all bets are off. It can modify your bootloader or kernel, inserting its own code to return valid results whenever any kind of malware checker scans for it. The only way to reliably identify it is to either move the disk to another system or to cold boot off verified media. By restricting pre-OS code to something that's been signed, Secure Boot does provide enhanced security.
Secure Boot is just another name for Trusted BootUntrue. Trusted Boot requires the ability to measure the entire boot process, which gives the OS the ability to figure out everything that's been run before OS startup. The root of trust is in the hardware and a TPM is required. Secure Boot is simply a way to limit the applications that are run before the OS. Once booted, there is no way for the OS to identify what was previously booted, or even if the system was booted securely.
Microsoft are just requiring that vendors implement the specificationUntrue. Quoting from the Windows 8 Hardware Certification Requirements:

MANDATORY: No in-line mechanism is provided whereby a user can bypass Secure Boot failures and boot anyway Signature verification override during boot when Secure Boot is enabled is not allowed. A physically present user override is not permitted for UEFI images that fail signature verification during boot. If a user wants to boot an image that does not pass signature verification, they must explicitly disable Secure Boot on the target system.

Section 27.7.3.3 of version 2.3.1A of the UEFI spec explicitly permits implementations to provide a physically present user override. Whether this is a good thing or not is obviously open to argument, but the fact remains that Microsoft forbid behaviour that the specification permits.
Secure Boot can be used to implement DRMUntrue. The argument here is that Secure Boot can be used to restrict the software that a machine can run, and so can limit a system to running code that implements effective copy protection mechanisms. This isn't the case. For that to be true, there would need to be a mechanism for the OS to identify which code had been run in the pre-OS environment. There isn't. The only communication channel between the firmware and the OS is via a single UEFI variable called "SecureBoot", which may be either "1" or "0". Additionally, the firmware may provide a table to the OS containing a list of UEFI executables that failed to authenticate. It is not required to provide any information about the executables that authenticated correctly.

In both these cases, the OS is required to trust the firmware. If the firmware has been compromised in any way (such as the user turning off Secure Boot), the data provided by the firmware can be trivially modified and the OS told that everything is fine. As long as machines exist where users are permitted to disable Secure Boot, Secure Boot is not any kind of DRM scheme.
Secure Boot provides physical securityUntrue. Secure Boot does not in any way claim to improve security against attackers who have physical access, for the same reasons as the DRM case. The OS has no way to determine that the firmware's behaviour has been modified. A physically-present attacker can simply disable Secure Boot and install a piece of malware that lies to the OS about platform security. The "Evil Maid" attack still exists.
Secure Boot only defines the interaction between the firmware and the bootloader. It doesn't specify any higher policyMisleading. It's true that Secure Boot only specifies the authentication of pre-OS code. However, if you implement Secure Boot it's because you want to ensure that only authenticated code has run before your OS. If there is any way for unauthenticated code to touch the hardware before your OS starts, you can't ensure that. If an authenticated Linux kernel is booted and then loads an unsigned driver, that unsigned driver can fabricate a fake UEFI environment and then launch Windows from it. Windows would falsely believe that it has booted securely. If that authenticated Linux kernel were widely distributed, attackers could use it as an attack vector for Windows. The logical response from Microsoft would be to blacklist that kernel.

The inevitable outcome of implementing Secure Boot is that every component that can touch hardware must be signed. Anyone who implements Secure Boot without requiring that is adding no additional security whatsoever.
Only machines that want to boot Windows need to carry Microsoft's keysAgain, misleading. Microsoft only require one signing key to be installed, and the Windows bootloader will be signed with a key that chains back to this one. However, the bootloader is not the only component that must be signed. Any drivers that are carried on ROMs on plug-in cards must also be signed. One approach here would have been for all hardware vendors to have their own keys. This would have been unscalable - any shipped machine would have to carry keys for every vendor who produces PCI cards. If a machine carried an nvidia key but not an AMD one, swapping a geforce for a radeon would have resulted in the firmware graphics driver failing to load. Instead, Microsoft are providing a signing service. Vendors will be able to sign up for WHQL membership and have their UEFI drivers signed by Microsoft.

This leads to the problem. The Authenticode format used for signing UEFI objects only allows for a single signature. If a driver is signed by Microsoft, it can't be signed by anybody else. Therefore, if a system vendor wants to support off-the-shelf PCI devices with Microsoft-signed drivers, the system must carry Microsoft's key. If the same key is used as the root of trust for the driver signing and for the bootloader signing, that also means that the system will boot Windows.
This is only a problem for clients, not serversNot strictly true. While Microsoft's current requirements don't mandate the presence of Secure Boot on server hardware, if present it must be enabled and locked down as it is for clients. It's not valid for servers to ship with disabled Secure Boot support, or for it to be shipped in a mode allowing users to make automated policy modifications at OS install time.
Secure Boot is required by NISTThis is one that I've heard from multiple people working on Secure Boot. It's amazingly untrue. The document they're referring to is NIST SP800-147, which is a document that describes guidelines for firmware security - that is, what has to be done to ensure that the firmware itself is secure. This includes making sure that the OS can't overwrite the firmware and that firmware updates must be signed. It says absolutely nothing about the firmware only running signed software. Secure Boot depends upon the firmware being trusted, so these guidelines are effectively a required part of Secure Boot. But Secure Boot is not within the scope of SP800-147 at all.
It's easy for Linux to implement Secure BootMisleading. From a technical perspective, sure. From a practical perspective, not at all. I wrote about the details here.
It's only a problem for hobbyist Linux, not the real Linux marketUntrue. It's unclear whether even the significant Linux vendors can implement Secure Boot in a way that meets the needs of their customers and still allows them to boot on commodity hardware. A naive implementation removes many of the benefits of Linux for enterprise customers, such as the ability to use local modifications to micro-optimise systems for specific workloads. One of the key selling points of Linux is the ability to make use of local expertise when adapting the product for your needs. Secure Boot makes that more difficult.

ConclusionMuch reporting on the issues surrounding Secure Boot so far has been inaccurate, leading to misunderstandings about the (genuine) benefits and the (genuine) drawbacks. Any useful discussion must be based around an accurate understanding of the specification rather than statements from analysts with no real understanding of the Linux market or security.

comments

but I ve already forseen the unwanted meet for some time . My elder daughter does need to run educational software from school. And my wife wants to run education software for our younger son. And making all that running under different emulation environments does eat my time, and result is not always good. And also children start to want games Issue 1. Need hardware to run more or less modern windows on. For last 6 years, my home network consists of a more or less powerful headless server, and 3 terminals to access that. Terminals are definitely too weak for windows. And server is needed in 24/7 mode so sorry no windows there. Likely solution for this is one of 3 terminals is actually dying (it is doing so already for months but still works, just hangs sometimes) and needs a replacement, so I can just replace it now and use more powerful hardware. Issue 2. Windows host or windows VM? While windows VM feels preferable for a such a deep-linux person as myself, I tend to think that dual-boot host is better here. If the very reason of allowing windows into this house is make it easy to install and run random windows software, then doing so in VM environment is explicitly against the goal. Issue 3. Use unlicensed windows or buy a license? Although absolute majority of windows users here is Russia use unlicensed windows, it is somewhat unfair to promote free software and use unlicensed windows at the same time. And windows home basic license is not that expensive after all. The setup that makes me less uncomfortable than others is:
- obtain powerful enough hardware, and install that instead of failing terminal,
- obtain windows 7 home basic license
- install dual boot linux + windows, and under linux install windows VM
- when needed, try windows VM first, and in case of any issues, immediately reboot into windows host. What I can t find out for some time already is does microsoft retail license allow to have both host and VM installation on the same computer? These will be physically different installations, but on the same computer, and will never run at the same time. License wording does not give exact answer on this. I wanted to ask on Microsoft s support forum but failed to register there. After asking me quite a few things it claimed that there is some temporary problem and suggested to retry later. I retried later and got the same. I then asked here but looks like nobody knows. At least I want to know, what will happen if I will try to activate windows in VM after I ve activated windows (with the same key) on host. Will this render both installations non-genuine ? Also I d appreciate any comments on the whole situation

Perf stats for "doing nothing" I've recently discovered the perf Linux tool. I heard that oprofile was deprecated and that there is a new tool, and I noted down to try it sometime. Updated: more languages, fixed typos, more details, some graphs. Apologies if this shows twice in your feed. The problem with perf stats is that I hate bloat, or even perceived bloat. Even when it doesn't affect me in any way, the concept of wasted cycles makes me really sad. You probably can guess where this is going I said, well, let's see what perf says about a simple "null" program. Surely doing nothing should be just a small number of instructions, right? Note: I think that perf also records kernel-side code, because the lowest I could get was about ~50K instructions for starting a null program in assembler that doesn't use libc and just executes the syscall asm instruction. However, these ~50K instructions are noise the moment you start to use more high-level languages. Yes, this is expected, but the I was still shocked. And there's lots of delta between languages I'd expected to behave somewhat identical. Again, this is not important in the real world. At all. They are just numbers, and probably the noise (due to short runtime) has lots of influence on the resulting numbers. And I might have screwed up the measurements somehow. Test setup Each program was the equivalent of 'exit 0' in the appropriate form for the language. During the measurements, the machine was as much as possible idle (single-user mode, measurements run at real-time priority, etc.). For compiled languages, -O2 was used. For scripts, a simple #!/path/to/interpreter (without options, except in the case of Python, see below) was used. Each program/script was run 500 times (perf's -r 500) and I've checked that the variations were small ( 0.80% on the metrics I used). You can find all the programs I've used at http://git.k1024.org/perf-null.git/, the current tests are for the tag version perf-null-0.1. The raw data for the below tables/graphs is at log-4. Results Compiled languages

Language	Cycles	Instructions
asm	63K	51K
c-dietlibc	74K	57K
c-libc-static	177K	107K
c-libc-shared	506K	300K
c++-static	178K	107K
c++-dynamic	1,750K	1,675K
haskell-single	2,229K	1,338K
haskell-threaded	2,629K	1,522K
ocaml-bytecode	3,271K	2,741K
ocaml-native	1,042K	666K

Going from dietlibc to glibc doubles the number of instructions, and for libc going from static to dynamic linking again roughly doubles it. I didn't manage to compile a program dynamically-linked against dietlibc. C++ is interesting. Linked statically, it is in the same ballpark as C, but when linked dynamically, it executes an order of magnitude more instructions. I would guess that the initialisation of the standard C++ library is complex? Haskell, which has a GC and quite a complex runtime, executes slightly less instructions than C++, but uses more cycles. Not bad, given the capabilities of the runtime. The two versions of the Haskell program are with the single-threaded runtime and with the multi-threaded one; not much difference. A fully statically-linked Haskell binary (not recommended usually) goes below 1M instructions, but not by much. OCaml is a very nice surprise. The bytecode runtime is a bit slow to startup, but the (native) compiled version is quite fast to start: only 2 number of instructions and cycles compared to C, for an advanced language. And twice as fast as Haskell . Nice! Shells

Language	Cycles	Instructions
dash	766K	469K
bash	1,680K	1,044K
mksh	1,258K	942K
mksh-static	504K	322K

So, dash takes ~470K instructions to start, which is way below the C++ count and a bit higher than the C one. Hence, I'd guess that dash is implemented in C . Next, bash is indeed slower on startup than dash, and by slightly more than 2 (both instructions and cycles). So yes, switching /bin/sh from bash to dash makes sense. I wasn't aware of mksh, so thanks for the comments. It is, in the static variant, more efficient that dash, by about 1.5 . However, the dynamically linked version doesn't look too great (dash is also dynamically linked; I would guess a statically-linked dash "beats" mksh-static). Text processing I've added perl here (even though it's a 'full' language) just for comparison; it's also in the next section.

Language	Cycles	Instructions
mawk	849K	514K
gawk	1,363K	980K
perl	2,946K	2,213K

A normal spread. I knew the reason why mawk is Priority: required is that it's faster than gawk, but I wouldn't have guessed it's almost twice as fast. Interpreted languages Here is where the fun starts

Language	Cycles	Instructions
lua 5.1	1,947K	1,485K
lua 5.2	1,724K	1,335K
lua jit	1,209K	803K
perl	2,946K	2,213K
tcl 8.4	5,011K	4,552K
tcl 8.5	6,888K	6,022K
tcl 8.6	8,196K	7,236K
ruby 1.8	7,013K	6,128K
ruby 1.9.3	35,870K	35,022K
python 2.6 -S	11,752K	10,247K
python 2.7 -S	11,438K	10,198K
python 3.2 -S	29,003K	27,409K
pypy -S	21,106K	10,036K
python 2.6	25,143K	21,989K
python 2.7	47,325K	50,217K
python 2.7 -O	47,341K	50,185K
python 3.2	113,567K	124,133K
python 3.2 -O	113,424K	124,133K
pypy	90,779K	68,455K

The numbers here are not quite what I expected. There's a huge delta between the fastest (hi Lua!) and the slowest (bye Python!). I wasn't familiar with Lua, so I tested it thanks to the comments. It is, I think, the only language which actually improves from one version to the next (bonus points), and where the JIT version also make is faster. In context, lua jit starts faster than C++. Perl is the one that goes above C++'s instructions count, but not by much. From the point of view of the system, a Perl 'hello world' is only about 1.3 -1.6x slower than a C++ one. Not bad, not bad. Next category is composed of TCL and Ruby, both of which had older versions 2-3 slower than Perl, but whose most recent versions are even more slower. TCL has an almost constant slowdown across versions (5M, 6.9M, 8.2M cycles), but Ruby seems to have taken a significant step backwards: 1.9.3 is 5 slower than 1.8. I wonder why? As for TCL, I didn't expect it to be slower to startup than Perl; good to know. Last category is Python. Oh my. If you run perf stat python -c 'pass' you get some unbelievable numbers, like 50M instructions to do, well, nothing. Yes, it has a GC, yes, it does import modules at runtime, but still On closer investigation, the site module and the imports it does do eat a lot of time. Running a simpler python -S brings it back to a more reasonable 10M instructions, which is in-line with the other interpreted languages. However, even with the -S taken into account, Python also slows down across versions: a tiny improvement from 2.6 to 2.7, but (like Ruby) a 3 slowdown from 2.7 to 3.2. Trying the optimised version (-O) doesn't help at all. Trying pypy, which was based on Python 2.7, makes it around 2 slower to startup (both with and without -S). So in the interpreted languages, it seems only Lua is trying to improve, the rest of the languages are piling up bloat with every version. Note: I should have tried multiple perl versions too. Java Java is in its own category; you guess why , right? GCJ was version 4.6, whereas by java below I mean OpenJDK Runtime Environment (IcedTea6 1.11) (6b24-1.11-4).

Language	Cycles	Instructions
null-gcj	97,156K	74,576K
java -jamvm	85,535K	80,102K
java -server	147,174K	136,803K
java -zero	132,967K	124,977K
java -cacao	229,799K	205,312K

Using gcj to compile to native code (not sure whether that's native-native or something else) results in a binary that uses less than 100M cycles to start, but the jamvm VM is faster than that (85M cycles). Not bad for java! Python 3.2 is slower to startup yes, I think the world has gone crazy. However, the other VMs are a few times slower: server (the default one) is ~150M cycles, and cacao is ~230M cycles. Wow. The other thing about java is that it was the only one that couldn't be put nicely in a file that you just exec (there is binfmt_misc indeed, but that doesn't allow different Java classes to use different Java VMs, so I don't count this), as opposed to every single other thing I tested here. Someone didn't grow on Unix? Comparative analysis Since there are almost 4 orders of magnitude difference between all the things tested here, a graph of cycles or instructions is not really useful. However, cycles/instruction, branches percentage and branches miss-predicted percentage can be. Hence first the cycles/instructions: Pypy is jumping out of the graph here, with the top value of over 2 cycles/instruction. Lua JIT is also bigger than Lua non-JIT, so maybe there's something to this (mostly joking, two data points don't make a series). On the other hand, Python wins as best cycles/instruction (0.91). Lots of ILP, to get below 1? Java gets, irrespective of VM, consistently near 1.0-1.1. C++ gets very different numbers between static linking (1.666) and dynamic linking (1.045), whereas C has basically identical numbers. mksh also has a difference between dynamic and static linking. Hmm Ruby, TCL and Python have consistent values across versions. And that's about what I can see from that graph. Next up, percentage of branches out of total instructions and percentage of branches missed: Note that the two lines shouldn't really be on the same graph; for the branch %, the 100% is the total instructions count, but for the branch miss %, the 100% is the total branch count. Anyway. There are two low-value outliers:

• dynamically-linked C++ has a low branch percentage (17.46%) and a very low branch miss percentage (only 4.32%)
• gcj-compiled java has a very low branch miss percentage (only 2.82%!!!), even though is has a regular branch percentage (20.85%)

So it seems the gcj libraries are well optimised? I'm not familiar enough with this topic, but on the graph it does indeed stand out. On the other end, mksh-static has a high branch miss percentage: 11.60%, which jumps clearly ahead of all the others; this might be why it has a high cycles/instruction count, due to all the stalls in misprediction; one has to wonder why it confuses the branch predictor? I find it interesting that the overall branch count is very similar across languages, both when most of the cost is in the kernel (e.g. asm) and when the user-space cost heavily over-weighs the kernel (e.g. Java). The average is 20.85%, minimum is 17.46%, max 22.93%, standard deviation (if I used gnumeric correctly) is just 0.01. This seems a bit suspicious to me . On the other hand, the mispredicted branches percentage varies much more: from a measly 2.82% to 11.60% (5x difference). Summary So to recap, counting just instructions:

• going from dietlibc to glibc: 2 increase
• going from statically-linked libc to dynamically-linked libc: doubles it again
• going from C to C++: 5 increase
• C++ to Perl: 1.3
• Perl to Ruby: 3
• Ruby to Python (-S): 1.6x
• Python -S to regular Python: 5x
• Python to Java: 1 -2 , depending on version/runtime
• branch percentage (per total instructions) is quite consistent across all of the programs

Overall, you get roughly three orders of magnitude slower startup between a plain C program using dietlibc and Python. And all, to do basically nothing. On the other hand, I learned some interesting things while doing it, so it wasn't quite for nothing .

When Jacob was just born, I wondered how I might introduce them to computing. I thought over various things, but that wasn t really the most pressing thing right then. I don t suppose that I could have predicted installing an XMPP IM server (Prosody) for the boys. And I certainly couldn t have predicted creating accounts named: jacob, oliver, butterfly, bear. Because, as Jacob pointed out to me, if (Jacob s favorite toy) butterfly is typing with his wings, then he shouldn t be logged in as Jacob. I admire my 5-year-old s security consciousness Anyhow, as I mentioned yesterday, Jacob and Oliver enjoy their computer, which I recently put on the LAN. The firewall does not pass any of its traffic to the Internet, though, with very limited exceptions. Jacob can read, and is starting to enjoy typing as well. So I thought he would enjoy sending IMs to me. As his computer has no GUI, I needed a text-mode client. Something with an IRC-like interface that could be scripted to open up a window with me directly sounded perfect. Initially I tried irssi s XMPP plugin, but it proved to be too buggy (wanting to always latch on to a particular resource on the remote end, not having very predictable window behavior, etc.) So I switched to mcabber. With a couple of quick configuration bits to get him automatically logged in, remove superflous windows, and connect him directly to a chat with me, it was set. And well-loved. He sent me a mix of real words and random things he created by replacing letters in Jacob or by holding down keys. In the mcabberrc, besides the obvious setting of username and password, there is:
set log_win_height = 1
set hook-post-connect = source ~/.mcabber/post-connect.rc
The hook is simply:
roster search Dad
roster hide
After awhile, Jacob wanted to switch computers. He wanted to use my laptop, and me use his computer. He refused to switch back. I asked him why. Because on your computer, my name is red. I should have known. I set it to bright white on his computer, but I think tomorrow we may need to upgrade him to the color monitor I ve been saving for just such an occasion It will be a whole new set of discoveries, I m sure. Update: I also tried out freetalk, which looked like it would meet my goals nicely. The problem was it didn t have a dedicated everything typed goes to this person mode. It did have a mode where it put the person s JID on the command line by default, but excessive use of backspace key by a 5-year-old could wipe that out and leave it in a state where he d be confused.

I ve just discovered that the magic database for the file(1) command in Debian/Unstable has no support for Linux Software RAID and that it s support for BTRFS is lacking (no reporting of space used, number of devices, or the UUID). Below is my first draft of a change to fix these problems. I would appreciate it if someone with a big-endian system could test these out and let me know how they go, I suspect that I will have to change the lelong types to long but I m not sure. 4096 lelong 0xa92b4efc Linux Software RAID
>4100 lelong x version 1.2 (%d)
>4112 belong x UUID=%8x:
>4116 belong x \b%8x:
>4120 belong x \b%8x:
>4124 belong x \b%8x
>4128 string x name=%s
>4168 lelong x level=%d
>4188 lelong x disks=%d 0 lelong 0xa92b4efc Linux Software RAID
>4 lelong x version 1.1 (%d)
>16 belong x UUID=%8x:
>20 belong x \b%8x:
>24 belong x \b%8x:
>28 belong x \b%8x
>32 string x name=%s
>72 lelong x level=%d
>92 lelong x disks=%d # BTRFS
0 10040 string _BHRfS_M BTRFS Filesystem
>0x1012b string >\0 label "%s",
>0 10090 lelong x sectorsize %d,
>0 10094 lelong x nodesize %d,
>0 10098 lelong x leafsize %d,
>0 10020 belong x UUID=%8x-
>0 10024 beshort x \b%4x-
>0 10026 beshort x \b%4x-
>0 10028 beshort x \b%4x-
>0x1002a beshort x \b%4x
>0x1002c belong x \b%8x,
>0 10078 lequad x %lld/
>0 10070 lequad x \b%lld bytes used,
>0 10088 lequad x %lld devices Related posts:

1. Label vs UUID vs Device Someone asked on a mailing list about the issues related...
2. Starting with BTRFS Based on my investigation of RAID reliability [1] I have...
3. Software vs Hardware RAID Should you use software or hardware RAID? Many people claim...

It probably comes as no surprise to anybody that Jacob has had a computer since he was 3. Jacob and I built it from spare parts, together. It may come as something of a surprise that it has no graphical interface, and Jacob uses the command line and loves it and did even before he could really read. A few months ago, I wrote about the fun Jacob had with speakers and a microphone, and posted a copy of the cheat sheet he has with his computer. Lately, Jacob has really enjoyed playing with the speech synthesizer both trying to make it say real words and nonsense words. Sometimes he does that for an hour. I was asked for a copy of the scripts I wrote. They are really simple. I gave them names that would be easy for a preschooler to remember and spell, even if they conflicted with existing Unix/Linux commands. I put them in /usr/local/bin, which occurs first on the PATH, so it doesn t matter if they conflict. First, for speech systhesis, /usr/local/bin/talk:
#!/bin/bash
echo "Press Ctrl-C to stop."
espeak -v en-us -s 150
espeak comes from the espeak package. It seemed to give the most consistenly useful response. Now, on to the sound-related programs. Here s /usr/local/bin/ssl, the sound steam locomotive . It starts playing a train sound if one isn t already playing:
#!/bin/bash
pgrep mpg321 > /dev/null mpg321 -q /usr/local/trainsounds/main.mp3 &
sl "$@"
And then there s /usr/local/bin/record:
#!/bin/bash
cd $HOME/recordings
echo "Now recording. Press Ctrl-C to stop."
DATE= date +%Y-%m-%dT%H-%M-%S
FILENAME="$DATE-$$.wav"
chmod a-w *.wav
exec arecord -c 1 -f S16_LE -c 1 -r 44100 "$FILENAME"
This simply records in a timestamped file. Then, its companion, /usr/local/bin/play. Sorry about the indentation; for whatever reason, it is being destroyed by the blog, but you get the idea.
#!/bin/bash
case "$1" in
train)
mpg321 /usr/local/trainsounds/main.mp3
;;
song)
/usr/bin/play /usr/local/trainsounds/traindreams.flac
;;
*)
cd $HOME/recordings
exec aplay ls -tr tail -n 1
;;
esac
So, Jacob can run just play , which will play back his most recent recording. As something of a bonus, the history of recordings is saved for us to listen to later. If he types play train , there is the sound of a train passing. And, finally, play song plays Always a Train in My Dreams by Steve Gillette (I heard it on the radio once and bought the CD). Some of these commands kick off sound playing in the background, so here is /usr/local/bin/bequiet:
#!/bin/bash
killall mpg321 &> /dev/null
killall play &> /dev/null
killall aplay &> /dev/null
killall cw &> /dev/null


If you met Ana, you ll easily remember her. She has a great and pronounced Spanish accent I m glad that the existence of the Debian Women project helped her to join Debian because she has been doing a great job. From KDE packaging to publicity/marketing work, her interests shifted over the years but this allowed her to stay very involved. As she explains it very well, Debian is big enough so that you can stop doing something which is no longer fun for you, and still find something new to do in another part of Debian! Read on to learn more about Ana, the KDE team, Debian s participation to the Google Summer of Code, and more. Raphael: Who are you? Ana: I m Ana Guerrero L pez and I m in my early 30s. I was born and raised in the wonderful city of Sevilla, Spain and I live in Lyon, France. I share my life with another Debian Developer and my paid work is doing Debian support and integration, so you won t be surprised to read that Debian is a big part of my life. Raphael: How did you start contributing to Debian? Ana: Although I knew about the existence of Linux since 1997 or so, I didn t really start using Linux until the summer 2001 when I finally got a computer on my own and an Internet link at home. In the beginning, I was using Mandrake in a dual boot with Windows and later around 2003, I happily moved to only using Debian and ditching the Windows partition. Once settled as a Debian user, I knew anybody could help improve the distribution but I hesitated to join mostly due to two reasons, my perception of Debian was the one of a very elitist and aggressive club and who wants to join this kind of cult^wproject? And even if I wanted to join, I did not know how to get started. By the summer of 2004, the Debian Women project started, it made me seeing Debian as a more welcoming project, and I started maintaining my first packages. The following summer 2005, I attended akademy 2005 (the annual KDE conference) where I had the pleasure to meet there some of the people from the KDE team and this really made a difference for me. Christopher Martin and Adeodato Sim , with the help of other people, have started the maintenance of KDE as a team a few months before and by that time most of the KDE modules where under the maintenance umbrella of the team. This was a very good move since it allowed easily to share the KDE maintenance in a more coordinated way and also eased having non-DDs, like me at that time, to join in and help.

The Debian Women project started, it made me seeing Debian as a more welcoming project.

Raphael: You re part of the Debian KDE team. What s your role in the team and what are your plans for Wheezy? Ana: Nowadays, I am not as active in the KDE team as I used to be in the past. The KDE 3 to KDE 4 transition was quite tiring and changes on the KDE side like the successive marketing renames, the shorter 6 months schedule (it used to be at least 9) or the uncoordinated KDE releases mostly burnt me out. Currently, I am mostly working in helping others to get started within the team, some small fixes here and there, and helping with the uploads: an upload of the full KDE suite to the archive requires some building power and upload bandwidth not everybody have. For Wheezy, with the tentative freeze date in June, the plan is to try to ship the latest possible point release of the KDE 4.8 series. The first release of the series, 4.8.0 was released a couple of weeks ago and while writing these lines, the packaging work for 4.8 hasn t started yet. The next move for the team is getting 4.7.4 in unstable, currently sitting in experimental.

For Wheezy, [ ] the plan is to try to ship the latest possible point release of the KDE 4.8 series.

Besides the KDE packages, there is some software which users perceive as KDE, such as amarok, digikam, etc., which are not part of KDE but fall under its umbrella. These other programs have their own maintainers and their updates depend greatly in the availability of them. For the KDE office suite, we have right now KOffice in the archive. KOffice got a fork some time ago named Calligra and we should replace KOffice by Calligra in the archive before the release of Wheezy. Sadly there isn t yet a final release of Calligra to use. My personal goal for Wheezy was to finish the removal of all the remaining packages depending on KDE 3 and Qt 3 that Squeeze still contained. The removal of the KDE 3 libraries and all the packages using them was quickly achieved after the release of Squeeze. The removal of Qt 3 soon showed that it was task harder than expected since some popular packages (sometimes not in the Debian archive, e.g. third-party scientific software) depend on it, and also Qt 3 is a requirement for LSB compatibility. Right now, Qt 3 has been orphaned for 9 months and nobody has shown any interest in adopting it. Raphael: KDE, much like GNOME, has been forked by people who were unhappy by the direction that the project has taken since version 4 (cf Trinity). What s your personal opinion on KDE 4.x and what s the position of the Debian KDE team concerning this fork? Ana: I use KDE 4 on my laptop and I think it is a solid desktop environment and platform. However I am finding it less and less attractive for me. On one side, my usage of the computer has been slightly changing and on the other side, I do not like how the new developments in KDE are evolving, things like plasmoids or activities are not attractive for me. I have switched my other 2 systems to awesome although I continue to use mainly a bunch of KDE applications: dolphin, konsole, kate, juk, kmix, etc. So you might say my desktop environment is an awesome KDE. Regarding the Trinity project, a lot of users complained very loudly when KDE 3 got replaced by KDE 4 in testing/unstable, so I find quite laudable the decision of some users to act instead and try to continue with a forked development of KDE 3. However the Trinity team seems to be about 3 persons (funny for a project named Trinity ) while KDE 3 is big. In perspective, it does not look that big because KDE 4 is even larger, but it is still too much for such small team. In addition those developers need to maintain Qt3 that has been end-of-lifed years ago by Nokia/Trolltech . So my guess is that sooner or later the project will fade away. Nobody from the KDE team is interested in Trinity and in case someone wants to package it for Debian, they would have to make a new team. For the reasons mentioned above: Qt3 maintenance and reduced upstream group, this would be a bad idea. My advice if you do not like KDE 4 and you miss KDE 3, would be taking a look at razor-qt based on Qt4 and quite similar to KDE 3. I read they have plans to port it to Qt4, but frankly that could take some years same it took to the KDE project for KDE 4.0.0 Raphael: You used to maintain news.debian.net, a WordPress blog dedicated to Debian, but you stopped a while ago. A few months later you started to maintain a Debian page on Google+. Why did you stop the blog and what s your goal with the Google+ page? Ana: I blogged about the reasons I started news.debian.net. In short, I thought Debian needed a better system to publish news, something like a blog. I first tried to suggest the idea to the press/publicity team but they weren t interested, so I started the project alone. IMHO the blog worked quite well and I was feeling like it should be made official. I talked about this with some people but at the time I wasn t pushing it because I had other priorities and I knew pushing it to become official would need some extra time and energy. Stefano decided to start the discussion about making news.debian.net official (that s moving it to a debian.org domain) in its own initiative. After the public discussion and some private exchange of emails with DSA, the situation became frustrating and I decided to close news.debian.net after the release of Squeeze. Later, during DebConf, an officer from the press team announced they were launching a blog and I asked Stefano if he could try to have a discussion about this to see if it could still somehow fit my ideas, and maybe contributing myself, but nobody from the press team answered Stefano s email and the blog hasn t started yet either. Irony that communication didn t work when wanting to improve communication. About the Google+ page, everyday I follow what is going in Debian and quite often I find things I want to share. I do not want to clutter my own profiles with Debian stuff or have people following me because of that, so I decided to create the Debian page when Google+ made them available. I like the fact that people can follow that without having an account in Google+ although they can not comment anonymously. I am not happy about the fact that Google+ is a closed platform but hopefully the data will become easier to export in the near future. Right now, there are some services that provides RSS feeds of Google+ pages if you want to follow the page and you are not in Google+ (or I could setup one if several people ask me). Raphael: Last year you helped to manage Debian s participation to the Google Summer of Code. How did it went? Is there something that you can improve for this year? Ana: I think last year we managed to have people in Debian more aware about what the students were doing. That also helped students to get more feedback and therefore get to know more people in the project and get more integrated. Students were sending periodic public reports available to everybody interested in the status of the projects and some of them also held their own sessions in DebConf. We still failed to start looking for mentors early enough and to give them information about how the GSoC worked and how they could have a successful project. Having good projects in Debian is harder than in other projects because the GSoC mostly promotes having students started in Open Source *coding* for a project, while Debian is more a project about integrating software and we overall do not have so many parts that has to be coded. My personal goal for this year is to try getting the projects earlier to attract good students from the very beginning, even if that means we have less projects than in other years. Raphael: What motivates you to continue to contribute year after year? Ana: Three things. I like improving the OS I use, I like the friends I have made while working in Debian through the years and because I have fun. Also Debian is quite a big project, so if you become tired or burn out working in some area, you always can easily find interesting things to do somewhere else. Raphael: Is there someone in Debian that you admire for their contributions? Ana: Adeodato Sim , he is now in a long leave from the project, but it is one of those persons who made a difference in the project in his job in the release team some years ago. Aur lien Jarno because of his tireless work in (e)glibc and porting of several architectures. I also have special admiration for all those people who have been very active in the project for more than 7-8 years because I know it is not always easy to combine it with real life.

---

Thank you to Ana for the time spent answering my questions. I hope you enjoyed reading her answers as I did. Note that older interviews are indexed on wiki.debian.org/PeopleBehindDebian.

Subscribe to my newsletter to get my monthly summary of the Debian/Ubuntu news and to not miss further interviews. You can also follow along on Identi.ca, Google+, Twitter and Facebook .

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Based on my investigation of RAID reliability [1] I have determined that BTRFS [2] is the Linux storage technology that has the best potential to increase data integrity without costing a lot of money. Basically a BTRFS internal RAID-1 should offer equal or greater data protection than RAID-6. As BTRFS is so important and so very different to any prior technology for Linux it s not something that can be easily deployed in the same way as other filesystems. It is possible to easily switch between filesystems such as Ext4 and XFS because they work in much the same way, you have a single block device which the filesystem uses to create a single mount-point. While BTRFS supports internal RAID so it may have multiple block devices and it may offer multiple mountable filesystems and snapshots. Much of the functionality of Linux Software RAID and LVM is covered by BTRFS. So the sensible way to deploy BTRFS is to give it all your storage and not make use of any other RAID or LVM. So I decided to do a test installation. I started with a Debian install CD that was made shortly before the release of Squeeze (it was first to hand) and installed with BTRFS for the root filesystem, I then upgraded to Debian/Unstable to get the latest kernel as BTRFS is developing rapidly. The system failed on the first boot after upgrading to Unstable because the /etc/fstab entry for the root filesystem had the FSCK pass number set to 1 which wasn t going to work as no FSCK program has been written. I changed that number to 0 and it then worked. The initial install was on a desktop system that had a single IDE drive and a CD-ROM drive. For /boot I used a degraded RAID-1 and then after completing the installation I removed the CD-ROM drive and installed a second hard drive, after that it was easy to add the other device to the RAID-1. Then I tried to add a new device to the BTRFS group with the command btrfs device add /dev/sdb2 /dev/sda2 and was informed that it can t do that to a mounted filesystem! That will decrease the possibilities for using BTRFS on systems with hot-swap drives, I hope that the developers regard it as a bug. Then I booted with an ext3 filesystem for root and tried the btrfs device add /dev/sdb2 /dev/sda2 again but got the error message btrfs: sending ioctl 5000940a to a partition! which is not even found by Google. The next thing that I wanted to do was to put a swap file on BTRFS, the benefits for having redundancy and checksums on swap space seem obvious and other BTRFS features such as compression might give a benefit too. So I created a file by using dd to take take from /dev/zero, ran mkswap on it and then tried to run swapon. But I was told that the file has holes and can t be used. Automatically making zero blocks into holes is a useful feature in many situations, but not in this case. So far my experience with BTRFS is that all the basic things work (IE storing files, directories, etc). But the advanced functions I wanted from BTRFS (mirroring and making a reliable swap space) failed. This is a bit disappointing, but BTRFS isn t described as being ready for production yet.

• [1] http://etbe.coker.com.au/2012/02/06/reliability-raid/
• [2] http://en.wikipedia.org/wiki/Btrfs

Related posts:

1. Discovering OS Bugs and Using Snapshots I m running Debian/Unstable on an EeePC 701, I ve got an...
2. Reliability of RAID ZDNet has an insightful article by Robin Harris predicting the...
3. How I Partition Disks Having had a number of hard drives fail over the...

Matthew Aslett wrote about how the proportion of projects released under GPL-like licenses appears to be declining, at least as far as various sets of figures go. But what does that actually mean? In absolute terms, GPL use has increased - any change isn't down to GPL projects transitioning over to liberal licenses. But an increasing number of new projects are being released under liberal licenses. Why is that?

The figures from Black Duck aren't a great help here, because they tell us very little about the software they're looking at. FLOSSmole is rather more interesting. I pulled the license figures from a few sites and found the following proportion of GPLed projects:

RubyForge: ~30%
Google Code: ~50%
Launchpad: ~70%

I've left the numbers rough because there's various uncertainties - should proprietary licenses be included in the numbers, is CC Sharealike enough like the GPL to count it there, that kind of thing. But what's clear is that these three sites have massively different levels of GPL use, and it's not hard to imagine why. They all attract different types of developer. The RubyForge figures are obviously going to be heavily influenced by Ruby developers, and that (handwavily) implies more of a bias towards web developers than the general developer population. Launchpad, on the other hand, is going to have a closer association with people with an Ubuntu background - it's probably more representative of Linux developers. Google Code? The 50% figure is the closest to the 56.8% figure that Black Duck give, so it's probably representative of the more general development community.

The impression gained from this is that the probability of you using one of the GPL licenses is influenced by the community that you're part of. And it's not a huge leap to believe that an increasing number of developers are targeting the web, and the web development community has never been especially attached to the GPL. It's not hard to see why - the benefits of the GPL vanish pretty much entirely when you're never actually obliged to distribute the code, and while Affero attempts to compensate from that it also constrains your UI and deployment model. No matter how strong a believer in Copyleft you are, the web makes it difficult for users to take any advantage of the freedoms you'd want to offer. It's as easy not to bother.
So it's pretty unsurprising that an increase in web development would be associated with a decrease in the proportion of projects licensed under the GPL.

This obviously isn't a rigorous analysis. I have very little hard evidence to back up my assumptions. But nor does anyone who claims that the change is because the FSF alienated the community during GPLv3 development. I'd be fascinated to see someone spend some time comparing project type with license use and trying to come up with a more convincing argument.

(Raw data from FLOSSmole: Howison, J., Conklin, M., & Crowston, K. (2006). FLOSSmole: A collaborative repository for FLOSS research data and analyses. International Journal of Information Technology and Web Engineering, 1(3), 17 26.)

comments

After not attending FOSDEM for a few years, this year I decided to attend and also give a talk about Debian packaging for beginners , a replay of a talk given by Gergely Nagy in Debconf11 (video). As the per distribution devrooms were replaced a few years ago with the cross-distributions rooms, I thought it might be a good chance to have this kind of introduction talk to help people started contributing to Debian (or derived distributions). The talk wasn t meant to replace reading the documentation (new maintainer s guide, developer s references and the debian policy), but it s a good start for those who want some hands-on experience. The idea is to start with a just the upstream directory and progress trough the various errors and warnings we get during the build process using dpkg-buildpackage. The outcome is of course very basic, but enough to get people ready to do things on their own, including various QA tests on the package (e.g. lintian and debdiff). The presentation covers the important points of the 3 main files in the debian directory: control, changelog and rules. It addition it holds some information about the various tools one can used to test the packages. I hope to make another version of the presentation to be more standalone than just having the main points during the talk itself.
Filed under: Debian GNU/Linux, FOSDEM

Dear Lazyweb, is it possible to tell aptitude to show older versions of a package next to the currently available one if it is still present in /var/cache/apt/archives? Like it does when you use unstable and experimental side by side? I know that aptitude does not really support downgrades of packages, but showing those packages directly in aptitude if available in the cache is a lot easier than searching them in the file system and installing them manually, especially if you don t know where they hide.

This is the second entry in my series about squeeze release critical bug squashing. In response to my last blog post it was asked whether this is proper release critical bug squashing. Indeed there haven't been any patches or upload involved in this, only BTS handling, but this doesn't mean that these bugs weren't considered to be affecting squeeze. You can see this effort currently as weeding out the "wrong" bugs so that the list gets more useful and actually be able to ask maintainers to address the real issues. You can at least see in this graph that the blue line is going down constantly since the year change instead of rising up like before. And I hope I will be able to keep it below the green line for a while still. Also thanks to the release-team and ftpmasters that it was possible to keep the massbugs about waf binary blob not being preferred source for modification out of affecting squeeze and ignore it for the current stable release the required changes for those would rather be a fair bit intrusive for a stable update.

• 637213: doesn't fail in squeeze
• 648989: doesn't fail in squeeze
• 584568: most stuff (BTS, PTS, ...) use maintainer information from unstable only
• 624464: most stuff (BTS, PTS, ...) use maintainer information from unstable only
• 632106: most stuff (BTS, PTS, ...) use maintainer information from unstable only
• 632108: most stuff (BTS, PTS, ...) use maintainer information from unstable only
• 632262: most stuff (BTS, PTS, ...) use maintainer information from unstable only
• 632264: most stuff (BTS, PTS, ...) use maintainer information from unstable only
• 632265: most stuff (BTS, PTS, ...) use maintainer information from unstable only
• 632266: most stuff (BTS, PTS, ...) use maintainer information from unstable only
• 595298: squeeze has linux 2.6.32
• 613732: doesn't fail in squeeze
• 616694: doesn't fail in squeeze
• 620264: doesn't fail in squeeze
• 620573: doesn't fail in squeeze
• 621440: libdb4.8 not obsolete in squeeze
• 624593: doesn't fail in squeeze
• 626868: doesn't fail in squeeze
• 628475: libdb4.8 not obsolete in squeeze
• 629838: boost1.46 not in squeeze
• 628475: boost1.46 not in squeeze
• 631623: doesn't fail in squeeze
• 639990: doesn't fail in squeeze
• 632763: no libevent 2.0 in squeeze
• 627000: not affecting squeeze
• 658216: doesn't fail in squeeze
• 654870: doesn't fail in squeeze
• 655115: this is explicitly about testing
• 657092: working in squeeze
• 655710: doesn't fail in squeeze
• 644691: no nautilus 3 in squeeze

I am glad that I managed to keep it up and even have a nice margin in case I can't put any effort into it some day but still have more bugs squashed than days there are in the year so far. Currently I am at 60 bugs in 39 days. This gives a warm feeling. :) Enjoy!

/debian permanent link Comments: 3 Flattr this

Something interesting I discovered about Python and --prefix that I can't see a lot of documentation on... When you build Python you can use the standard --prefix flag to configure to home the installation as you require. You might expect that this would hard-code the location to look for the support libraries to the value you gave; however in reality it doesn't quite work like that. Python will only look in the directory specified by prefix after it first searches relative to the path of the executing binary. Specifically, it looks at argv[0] and works through a few steps is argv[0] a symlink? then dereference it. Does argv[0] have any slashes in it? if not, then search the $PATH for the binary. After this, it starts searching for dirname(argv[0])/lib/pythonX.Y/os.py, then dirname(argv[0])/../lib and so on, until it reaches the root. Only after these searches fail does the interpreter then fall back to the hard-coded path specified in the --prefix when configured. What is the practical implications? It means you can move around a python installation tree and have it all "just work", which is nice. In my situation, I noticed this because we have a completely self-encapsulated build toolchain, but we wish to ship the same interpreter on the thing that we're building (during the build, we run the interpreter to create .pyc files for distribution, and we need to be sure that when we did this we didn't accidentally pick up any of the build hosts python; only the toolchain python). The PYTHONHOME environment variable does override this behaviour; if it is set then the search stops there. Another interesting thing is that sys.prefix is therefore not the value passed in by --prefix during configure, but the value of the current dynamically determined prefix value. If you run an strace, you can see this in operation. Firstly it dereferences symlinks. Then it looks for Modules/Setup to see if it is running out of the build tree. Then it starts looking for os.py, walking its way upwards. One interesting thing that may either be a bug or a feature, I haven't decided, is that if you set the prefix to / then the interpreter will not go back to the root and then look in /lib. This is probably pretty obscure usage though! All this is implemented in Modules/getpath.c which has a nice big comment at the top explaining the rules in detail.

If you ever get this cryptic error when loading an Android native app:

FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo org.wikibooks.OpenGL/android.app.NativeActivity : java.lang.IllegalArgumentException: Unable to load native library: /data/data/org.wikibooks.OpenGL/lib/libnative-activity.so
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1768)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1784)
       at android.app.ActivityThread.access$1500(ActivityThread.java:123)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
       at android.os.Handler.dispatchMessage(Handler.java:99)
       at android.os.Looper.loop(Looper.java:130)
       at android.app.ActivityThread.main(ActivityThread.java:3835)
       at java.lang.reflect.Method.invokeNative(Native Method)
       at java.lang.reflect.Method.invoke(Method.java:507)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605)
       at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalArgumentException: Unable to load native library: /data/data/org.wikibooks.OpenGL/lib/libnative-activity.so
       at android.app.NativeActivity.onCreate(NativeActivity.java:199)
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1722)
       ... 11 more

This may mean that Java couldn't find the ANativeActivity_onCreate function in your code, because it was stripped by the compiler. If you use the native_app_glue NDK module, you may have noticed this strange code:

    // Make sure glue isn't stripped.
    app_dummy();

Let's experiment what happens with and without this line: Calling app_dummy:

$ arm-linux-androideabi-objdump -T libs/armeabi/libnative-activity.so    grep ANativeActivity_onCreate
000067fc g    DF .text  000000f8 ANativeActivity_onCreate

Not calling app_dummy :

$ arm-linux-androideabi-objdump -T libs/armeabi/libnative-activity.so   grep ANativeActivity_onCreate
$   # nothing

native_app_glue mainly defines Android callbacks. Since none of them are called directly by your code, the compiler strips the android_native_app_glue.o module entirely. If you use app_dummy however, it embeds it. Fortunately the compiler cannot strip the module on a per-function basis That's why you need to call app_dummy when using the native_app_glue NDK module. This looks like a ugly work-around though - isn't there a cleaner way?

Part of our efforts to reduce power consumption is to identify processes which keep waking up the disk even when the computer is idle. This already resulted in a few bug reports (and some fixes, too), but we only really just began with this. Unfortunately there is no really good tool to trace file access events system-wide. powertop claims to, but its output is both very incomplete, and also wrong (e. g. it claims that read accesses are writes). strace gives you everything you do and don t want to know about what s going on, but is per-process, and attaching strace to all running and new processes is cumbersome. blktrace is system-wide, but operates at a way too low level for this task: its output has nothing to do any more with files or even inodes, just raw block numbers which are impossible to convert back to an inode and file path. So I created a little tool called fatrace ( file access trace , not fat race ) which uses fanotify, a couple of /proc lookups and some glue to provide this. By default it monitors the whole system, i. e. all mounts (except the virtual ones like /proc, tmpfs, etc.), but you can also tell it to just consider the mount of the current directory. You can write the log into a file (stdout by default), and run it for a specified number of seconds. Optional time stamps and PID filters are also provided.

$ sudo fatrace
rsyslogd(967): W /var/log/auth.log
notify-osd(2264): O /usr/share/pixmaps/weechat.xpm
compiz(2001): R device 8:2 inode 658203
[...]

It shows the process name and pid, the event type (Rread, Write, Open, or Close), and the path. Sometimes its not possible to determine a path (usually because it s a temporary file which already got deleted, and I suspect mmaps as well), in that case it shows the device and inode number; such programs then need closer inspection with strace. If you run this in gnome-terminal, there is an annoying feedback loop, as gnome-terminal causes a disk access with each output line, which then causes another output line, ad infinitum. To fix this, you can either redirect output to a file (-o /tmp/trace) or ignore the PID of gnome-terminal (-p pidof gnome-terminal ). So to investigate which programs are keeping your disk spinning, run something like

  $ sudo fatrace -o /tmp/trace -s 60

and then do nothing until it finishes. My next task will be to write an integration program which calls fatrace and powertop, and creates a nice little report out of that raw data, sorted by number of accesses and process name, and all that. But it might already help some folks as it is right now. The code lives in bzr branch lp:fatrace (web view), you can just run make and sudo ./fatrace. I also uploaded a package to Ubuntu Precise, but it still needs to go through the NEW queue. I also made a 0.1 release, so you can just grab the release tarball if you prefer. Have a look at the manpage and --help, it should be pretty self-explanatory.

A year ago, during FOSDEM 2011, I walked up to the NamurLUG folks who'd been doing video coverage of FOSDEM for years, and suggested that this year, maybe they should consider using dvswitch for video coverage. While they seemed agreeable to this idea, they simply had not had the time to look at it in detail, and were therefore not using it. Since I've used dvswitch in the past, both as part of the DebConf video team and for my own concert recordings, I reasoned this a problem that could be solved by joining the video team. However, when it came to be time to start preparing for FOSDEM 2012, we found that many of the NamurLUG people were not going to have as much time to prepare for video coverage as they had during past years, and therefore responsibility of FOSDEM video coverage fell entirely to me. This was fairly unexpected, though not too daunting. For those of you who don't know dvswitch very well: a typical dvswitch installation for coverage of a talk requires:

• Two cameras; one to capture the speaker, one to capture audience members asking questions.
• A twinpact 100, used to convert a VGA output into a DV stream that we can load into dvswitch
• Three laptops: one for the audience camera, one for the twinpact, and one for the speaker camera and the dvswitch installation
• A GigE network between the three laptops, with an uplink to do streaming
• A large amount of diskspace to store the recordings on. Since dvswitch records in raw DV, you require approximately 13GB per hour of recorded video.
• Some powerful systems to do transcoding from DV to a streaming format such as Ogg Theora or WebM
• A fairly extensive audio setup: one wireless headset microphone for the speaker, one or two wireless handheld microphones for people in the audience, and a number of microphones at select positions in the room to pick up ambient noise (which for obvious reasons you don't want to overdo on, but which if done well makes the audio on your recording sound much more natural). This also requires a mixing console.
• And last but not least a (network of) streaming server(s) to do the streaming to people watching from home.

This is a rather large amount of work, and therefore it is not too unexpected that for DebConf, the DebConf video team takes a week to properly set up two rooms so that they can be used for recording. However, for FOSDEM we only have less than a day on-site to set up things, and we were going to cover five rooms. So, I tried to cut corners as much as possible:

• We were going to work with one camera per room, rather than two. Not only would this reduce the number of required volunteers (of which I wasn't sure yet at that point how I'd find them), it would also reduce the amount of preparation needing to be done, and it would reduce the number of things that could go wrong.
• We were going to have the network team do our network, rather than try to do it ourselves. The result was that we were not going to have to lay out cables, cut them, crimp connectors on them, test them, etc, and would only need to worry about using the network, instead of building it.
• Since I'd read Thomas' announcement about an ''offer I cannot refuse'', I contacted him to see about that offer and get it all set up for FOSDEM. This way, I wouldn't have to worry about streaming servers etc, instead just about getting a stream on the network, into a flumotion server running somewhere; and after that, it would no longer be my problem.
• I decided to simplify the audio setup somewhat, and not use ambient mics. These are nice, but not essential, so we could do without them, and that would be (at least) two microphones per room that the team wouldn't have to rent, place, wire up, and tune.

So in the end, I would need to take care of ten firewire-capable laptops, five cameras, five mixing consoles, several microphones, a number of transcoding machines, and shitloads of cabling (power, firewire, and audio). And about a week or two before the conference, as the massiveness of what we were about to do started to sink in, I was starting to have bad dreams of what would happen, wondering what I'd gotten myself into this time. Now, one day after FOSDEM, I have to say it all turned out okay, but there are some things where there's still room for improvement. So that I don't forget, I thought I'd make a list of things that went well, and one of things that didn't go well. And since that might be interesting for other people, I thought I'd do it here, rather than in a private file. First, things that did not go so well:

1. Set-up for some rooms took more time than we had, and as such some rooms did not get properly streamed or recorded for their first few talks. This was due to the fact that there was some confused communication between some members of the team, which meant that we lost a day that we'd planned for preparation, and as such we couldn't test as much as we'd hoped. We need to improve on that next year. Ideally, we should run the full set-up somewhere, with all cameras and all laptops running, and making sure that everything is ready to be set up and that we have every cable we need, before dividing everything over a number of boxes (one per room) and bringing it to the conference.
2. While some of our cameras were semi-professional Panasonic cameras that had a balanced XLR audio input, others were much lower-level camcorder-style cameras that did not have such a thing. When a camera has a good audio input, it's fairly easy to set up a link from the mixing console to the camera and get the audio into the stream that way. When a camera does not have such a thing, the set-up gets much more complex. Since we had so much to worry about, we did not notice that in one room, on saturday, something went wrong with audio. To combat this, we should improve on our audio set-up for next year, and also verify the streams every once in a while (I did the latter on sunday, so everything should be fine there).
3. Inherent to an ad-hoc network, there were some network-related issues. For instance, on sunday evening, during the last session in that room, Ben informed me that the link to room H.1301 had gone down. As we were investigating, we easily found the source of the problem:
   
   The cable had been put under a door, and had been 'protected' with loads and loads of duct tape, but apparently that wasn't enough. This wasn't something we wanted to fix anymore, at that point; instead, we just let the cable be and focused on other things.
4. Storage. None of the systems used for the recordings were my own; instead, some were owned by IRILL and some were rented. If I want to do anything with my recordings, that means I have to copy the data off. The system I chose was to bring a USB3 hard disk and copy everything over; but for saturday, this took an hour and thirty minutes. On sunday, my USB3 disk was fairly full, so I had to revert to a USB2 one, which increased the time by much. In the end, we had to abort copying files, and we'll now have to be a bit creative to get them.
5. Volunteer management. I originally set up a wiki page to allow people to sign up for talks that they wanted to help out with. Unfortunately, that didn't work so well as it did for DebConf; there were several talks that did not have enough people, resulting in the volunteers from the previous talk remaining on post and finishing their talk. Also, there were some people that signed up without contacting me, or without telling me what name they used on the wiki page, which made it somewhat harder to know who to talk to. I lost count of who had signed up to help out. On Sunday, I decided to set up an IRC channel instead, through which volunteers could communicate more directly and just ask for people to take over, instead of registering for a talk first and then hoping nobody would forget. Also, since I'm terribly bad with faces and video volunteers did not have anything that made them stand out from the rest, I couldn't just walk around until I would see someone involved with video work and ask them to take over in a room. Having a separate 'video team' t-shirt could help there.

After the bad news, here's the list of things that did go well:

1. Streaming. Even though choosing flumotion rather than icecast (as we'd done for streaming in the past) involved extra work for me before the conference (I had to write some code so that I could stream from dvswitch into flumotion, which wasn't possible out of the box), the guys at Flumotion decided to send over one of their support engineers. As such, I simply did not have to worry about streaming servers crashing or failing to do what they were supposed to do. While I have no reason to think any of the Flumotion servers were having issues, even if they were I wouldn't have known about it, since Francesc took care of it all and never ever required my involvement about something on the flumotion side. This was extremely valuable.
2. Training right before the welcome talk. Explaining to people in a few words how dvswitch works, and then immediately following that up with a live demonstration, isn't a bad way for them to understand.
3. Despite all the problems we did have, once everything had been set up and all the gear was more or less manned, actually recording and streaming did go fairly well. The feedback I received so far was mostly positive, which makes me very happy.

In the end, while there certainly is still room for improvement and things did not go as smoothly as I'd hoped, they have gone much better than my worst fears. There's still some work to do, which I'll be doing with the NamurLUG people this week, but all in all, it's gone pretty good. As to the usage of the streams, I asked Flumotion for some statistics. Since I was fairly late in asking, they could only provide me with statistics about sunday:

• Number of clients connecting:
  
• Traffic:
  

The following announce is lazily copied from Paul Wise's announce. There is only one thing I like to add: the screenshots that are submitted and collected on screenshots.debian.net are visible on the packages websites (both Debian and Ubuntu) and are also used by the software-center package, so they help people to get a first impression of the package they might want to install. Have you ever wondered how to start getting involved in Debian/Ubuntu? Do you enjoy discovering new games and playing them? You might want to come to the games screenshot party! We hope that the party will be a fun, easy, low-commitment way to get involved. The Debian/Ubuntu Games Team is organizing a half-day screenshots party on the weekend of 25th-26th February for creating screenshots for all the games that are available in Debian/Ubuntu. If you are interested in attending, please add your availability to the poll linked from the announcement so that we can get some idea of attendance and when is a good time for the people who are interested. Look forward to lots of game playing, screenshots and merry time, hope to see you all there!

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