Ubuntu
alsa-lib package

dmix consumes 100% CPU with 32-bit userspace on 64-bit kernel

Bug #41367 reported by Jürgen Kreileder on 2006-04-25

Affects		Status	Importance	Assigned to	Milestone
	alsa-lib (Ubuntu)	Fix Released	Medium	Unassigned

Bug Description

32-bit processes using dmix on 64-bit kernels (e.g. powerpc with a powerpc64 kernel) consume 100% CPU.

A fix for this problem is in alsa-lib 1.0.11 (changelog entry: Fix timer read from 32bit user-space on 64bit kernel)

Daniel T Chen (crimsun) on 2006-04-25

Changed in alsa-lib:
status:	Unconfirmed → In Progress

Revision history for this message

Daniel T Chen (crimsun) wrote on 2006-04-30:

05_fix_timer_read_poll_100_percent_cpu__malone_41367.diff.dpatch

Changed in alsa-lib:
status:	In Progress → Fix Committed

Revision history for this message

Daniel T Chen (crimsun) wrote on 2006-04-30: debdiff for alsa-lib_1.0.10-2ubuntu2 (accumulated fixes)

debdiff for alsa-lib_1.0.10-2ubuntu2 (accumulated fixes) Edit (21.2 KiB, text/plain)

The above debdiff contains accumulated backported fixes from alsa-lib_1.0.11 in three categories:

Memory leak fixes: 05_fix_mem_double_free,05_fix_mem_leaks_1,05_fix_mem_leaks_2,05_fix_mem_leaks_3

Minor fixes: 05_fix_nonblocking_mode_typo,05_fix_plugin_dmix_crackling_from_byteswapping,05_fix_possible_infinite_loop_in_snd-pcm-wait_when_xrun

32/64-bit cpu polling issue: 05_fix_timer_read_poll_100_percent_cpu__malone_41367

The last dpatch contains the fix for this bug #41367.

Revision history for this message

Daniel T Chen (crimsun) wrote on 2006-05-02:

I'm attaching clarification from Takashi regarding the rbuf structure, since a question was raised regarding the consistency of accessing it.

Changed in alsa-lib:
status:	Fix Committed → In Progress

Revision history for this message

Daniel T Chen (crimsun) wrote on 2006-05-02: Clarification from Takashi Iwai regarding consistency of accessing the rbuf structure

Clarification from Takashi Iwai regarding consistency of accessing the rbuf structure Edit (2.2 KiB, text/plain)

Adam Conrad raised a concern regarding the change in the fix for this bug. I've e-mailed Takashi, and he responded thusly.

Revision history for this message

Martin Pitt (pitti) wrote on 2006-05-02:

alsa-lib (1.0.10-2ubuntu2) dapper; urgency=low
.
   * debian/patches/: Add:
     - Memory leak fixes: 05_fix_mem_double_free,05_fix_mem_leaks_1,
       05_fix_mem_leaks_2,05_fix_mem_leaks_3 .
     - Minor fixes: 05_fix_nonblocking_mode_typo,
       05_fix_plugin_dmix_crackling_from_byteswapping,
       05_fix_possible_infinite_loop_in_snd-pcm-wait_when_xrun
     - 32/64-bit cpu polling issue:
       05_fix_timer_read_poll_100_percent_cpu__malone_41367
       (Closes: Malone #41367).