DragonFly BSD Digest

Francois Tigeot has been working for quite a while on a VFS accounting system.  It doesn’t restrict to a quota (yet), but it will give you byte totals for each mounted filesystem.  It has been committed, so it looks like a good way to tell which PFS is eating your disk.

Update: Francois pointed out he’s still adding parts for this.  So it’s not quite done yet, but soon.

Buildworlds are now much faster, because they can run themselves in parallel.  Invoke it using the -j option to make.  Matthew Dillon saw a 25% reduction in time when using ‘make -j 12 buildworld’ on a 4-core system.  You may need to manually update xinstall and mkdir:

        cd /usr/src/usr.bin/xinstall
        make clean; make obj; make all install
        cd /usr/src/bin/mkdir
        make clean; make obj; make all install

It’ll also use more memory than a non-parallel build, but heck, that’s cheap these days.

Venkatesh Srinivas made a minor change to a ddb backtrace – it now prints the raw instruction pointers.  On x86_64, a backtrace would not print the correct objects out, so this is better.  It’s a minor change, but I’m pointing it out because it totally helped solve a problem for me on a package-building machine.

Jan Lentfer has updated ldns in DragonFly to version 1.6.11.  This brings in a bunch of bugfixes, which can be viewed at the ldns site’s changelog.

The general rule of thumb is that if you have a function written in an interpreted language (Perl, Python, etc.), it’ll be faster in C.  If you need it faster than that, you go to assembly.  Prepare to have your world rocked: Venkatesh Srinivas found that strlen() in libc was actually slower written in assembly than in C.  His commit message has numbers to back that up.

It’s another throughput tweak from Sepherosa Ziehau: soaccept is run differently when pulling in network data from a socket.  The commit message once again shows the results of the change using httperf.

Binutils in DragonFly is now up to version 2.22 – the commit linked is one of several.

Sepherosa Ziehau has implemented another networking speedup.  Read the commit message for details on what he changed, since it’s rather in-depth.  He shows an 18% improvement in netperf results.

Sepherosa Ziehau has implemented an asynchronous pru_send in sendfile.  The results are a 70-90% increase in performance, as shown in his netperf localhost test.

The man page for dfregress has been put together, and you can read it and find out how to contribute, right now.

(That man page should be up by the time this is posted…)

If you’re tracking DragonFly current, you will need to do a full buildworld on your next update.  Sepherosa Ziehau made some changes in route(8) that a quickworld will not catch.

Alex Hornung has created ‘dfregress’, a test framework designed to be as simple as possible for adding tests to DragonFly.  This would make it easier to verify an upcoming release is correct, for instance.  See his commit note for extensive details, and add a trivial test for anything you value.

This is another one of those features that I bet goes away, and nobody would notice because nobody uses it any more.  Sascha Wildner has removed AppleTalk from DragonFly.

DragonFly has a new memory allocator, called (not surprisingly) “dmalloc“.  It’s only present on x86_64, not i386, because it could eat up more VSZ (virtual memory) than an i386 kernel may  have available.

You can now have, in theory, up to 32 terabytes of RAM on your 64-bit DragonFly system, from a change made by Matthew Dillon.  I’m curious to see if anyone has even 1 terabyte, as that’s at least feasible.

John Marino has updated two libraries needed for gcc 4.4: GMP and MPFR.  They are, as far as I can tell, both designed for mathematical functions.

Matthew Dillon wrote up an explanation of how performance on systems with a lot of CPU cores has been significantly improved – up to 300%!  (He says 200%, but I think he’s treating it as a percentage of a whole rather than percent changed.)  Apparently finally getting rid of lock contention is the trick.

John Marino’s moved GCC from 4.4.6 to 4.4.7, but you’ll have to see the changelog for details.  Except it’s so new it isn’t listed… yet.

Sepherosa Ziehau made some changes that led to a 10% and then 20% gain (don’t know if that was cumulative or separate) in network speed for DragonFly.  That’s great!  It only has a noticeable effect if you’re on 10G Ethernet, though.  The obvious answer to that: upgrade your network.