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? -- Tanu
