[linux-audio-dev] Re: [announce] [patch] Voluntary Kernel Preemption Patch

[Andrew Morton]

Lee Revell <rlrevell at joe-job.com> wrote:
>
> > framebuffer scrolling inside lock_kernel().  Tricky.  Suggest you use X or
>  > vgacon.  You can try removing the lock_kernel() calls from do_tty_write(),
>  > but make sure you're wearing ear protection.
>  > 
> 
>  OK, I figured this was not an easy one.  I can just not do that.

Why not?  You can certainly try removing those [un]lock_kernel() calls.

>  Here are some more.  These result from using mplayer with ALSA OSS
>  emulation:
> 
>  Jul 13 04:31:49 mindpipe kernel:
>  Jul 13 04:31:49 mindpipe kernel: ALSA /usr/src/alsa-cvs-1.0.5/alsa-driver/alsa-kernel/core/pcm_lib.c:169: XRUN: pcmC0D0p
>  Jul 13 04:31:49 mindpipe kernel:  [__crc_totalram_pages+1387264/5353478] snd_pcm_period_elapsed+0x2ca/0x410 [snd_pcm]
>  Jul 13 04:31:49 mindpipe kernel:  [__crc_totalram_pages+1455070/5353478] snd_emu10k1_interrupt+0x3c8/0x480 [snd_emu10k1]
>  Jul 13 04:31:49 mindpipe kernel:  [handle_IRQ_event+49/96] handle_IRQ_event+0x31/0x60
>  Jul 13 04:31:49 mindpipe kernel:  [do_IRQ+155/352] do_IRQ+0x9b/0x160
>  Jul 13 04:31:49 mindpipe kernel:  [common_interrupt+24/32] common_interrupt+0x18/0x20
>  Jul 13 04:31:49 mindpipe kernel:  [__crc_totalram_pages+1394929/5353478] snd_pcm_format_set_silence+0x4b/0x1d0 [snd_pcm]
>  Jul 13 04:31:49 mindpipe kernel:  [__crc_totalram_pages+2165815/5353478] snd_pcm_oss_change_params+0x5a1/0x850 [snd_pcm_oss]
>  Jul 13 04:31:49 mindpipe kernel:  [__crc_totalram_pages+2166620/5353478] snd_pcm_oss_get_active_substream+0x76/0x90 [snd_pcm_oss]
>  Jul 13 04:31:49 mindpipe kernel:  [__crc_totalram_pages+2170556/5353478] snd_pcm_oss_get_formats+0x26/0x100 [snd_pcm_oss]

Looks like those memcpys in snd_pcm_format_set_silence() are hurting.