Re: preempt-timing-2.6.8-rc1

William Lee Irwin III
2004-07-14T10:33:45Z

At Wed, 14 Jul 2004 10:59:53 +0300, Lenar L?hmus wrote:
>> And this still seems to be very long and real:
>> 50ms non-preemptible critical section violated 2 ms preempt threshold
>> starting at snd_pcm_action_lock_irq+0x1b/0x1d0 [snd_pcm] and ending at
>> snd_pcm_action_lock_irq+0x65/0x1d0 [snd_pcm]
>> Trace has this:
>> [<f9239b09>] snd_pcm_playback_ioctl1+0x49/0x2f0 [snd_pcm]
>> So maybe this too is ioctl related (non-educated guess)?

On Wed, Jul 14, 2004 at 12:29:43PM +0200, Takashi Iwai wrote:
> If it's SNDRV_PCM_IOCTL_PREPARE, I'm modifying the relevant code with
> rwsem instead of rwlock. But it's still in BKL of ioctl. Do we need
> to unlock internally?

Yes, otherwise it'll be non-preemptible.

-- wli