On 2011-05-04 08:19, Tanu Kaskinen wrote: > Sorry for the delayed reply. > > On Wed, 2011-04-27 at 13:23 +0300, Dan Muresan wrote: >> I've patched (as in attachment) src/daemon/main.c to set the soft >> rttime limit lower than the hard limit. This way I was able to get a >> backtrace in gdb when pulseaudio received SIGXCPU due to excessive >> real-time CPU usage: >> >> #0 0x0012d422 in ?? () >> #1 0x00475edb in write () at ../sysdeps/unix/syscall-template.S:82 >> #2 0x00153a55 in pa_fdsem_post (f=0x806e178) at pulsecore/fdsem.c:205 >> #3 0x0013cb0f in push (l=0x8071bc8, p=0x8, wait_op=false) at >> pulsecore/asyncq.c:161 >> #4 0x0013d291 in pa_asyncq_post (l=0x8071bc8, p=0x80736d8) at >> pulsecore/asyncq.c:203 >> #5 0x0013c1ee in pa_asyncmsgq_post (a=0x8071a90, object=0xb6a16a08, >> code=7, userdata=0x0, offset=0, chunk=0xbffff590, free_cb=0) at >> pulsecore/asyncmsgq.c:139 >> #6 0x009811d7 in pstream_memblock_callback (p=0x808cf78, channel=0, >> offset=0, seek=PA_SEEK_RELATIVE, chunk=0xbffff590, userdata=0x80b6480) >> at pulsecore/protocol-native.c:4445 >> #7 0x001dd20b in ?? () from /usr/lib/libpulsecommon-0.9.22.so >> #8 0x001c823e in ?? () from /usr/lib/libpulsecommon-0.9.22.so >> #9 0x0021b5fb in pa_mainloop_dispatch () from /usr/lib/libpulse.so.0 >> #10 0x0021bb11 in pa_mainloop_iterate () from /usr/lib/libpulse.so.0 >> #11 0x0021bbd4 in pa_mainloop_run () from /usr/lib/libpulse.so.0 >> #12 0x08052e85 in main (argc=1, argv=0xbffff854) at daemon/main.c:974 >> >> Can someone point out the likely cause, or is this not enough >> information? This is pulseaudio 0.9.22 from Ubuntu Natty. > > I would guess that the excessive cpu use is caused by doing rewinds in > rapid succession. That's just a guess, though - the backtrace doesn't > really give any clue. There have been issues with rewinds happening in > some kind of a loop. David Henningson has been working on this problem > and he has made at least a few patches that help with the problem. The > patches are in Pulseaudio's git repository at least. Since David works > for Canonical, I would expect the fixes to be also in Ubuntu, but I > don't know for sure. > > David, what's the status of the "fighting rewinds" patches in Ubuntu > Natty? Is the problem supposed to be fixed already? > My rewind patches are both in Natty and stable-queue, but this bug is something different. IIRC I had a quick look at it, didn't have time to look really deep, so I just responded in the launchpad bug Dan also posted in (see https://bugs.launchpad.net/ubuntu/+source/linux-rt/+bug/367671 ) -- David Henningsson http://launchpad.net/~diwic
