Re: [patch] voluntary-preempt-2.6.9-rc1-bk4-Q5

From: Lee Revell
Date: Tue Aug 31 2004 - 12:30:35 EST


On Tue, 2004-08-31 at 11:17, Mark_H_Johnson@xxxxxxxxxxxx wrote:
> >I will be running some additional tests
> >- reducing preempt_max_latency
> >- running with sortirq and hardirq_preemption=0
> >to see if these uncover any further problems.
>
> #1 - audio driver
> latency: 621 us, entries: 28 (28)
> -----------------
> | task: latencytest/11492, uid:0 nice:0 policy:1 rt_prio:99
> -----------------
> => started at: snd_ensoniq_playback1_prepare+0x74/0x180
> => ended at: snd_ensoniq_playback1_prepare+0x11d/0x180
> =======>
> 00000001 0.000ms (+0.000ms): snd_ensoniq_playback1_prepare
> (snd_pcm_do_prepare)
> 00000001 0.014ms (+0.014ms): snd_es1371_dac1_rate
> (snd_ensoniq_playback1_prepare)
> 00000001 0.014ms (+0.000ms): snd_es1371_wait_src_ready
> (snd_es1371_dac1_rate)
> 00000001 0.562ms (+0.548ms): snd_es1371_src_read (snd_es1371_dac1_rate)
> 00000001 0.562ms (+0.000ms): snd_es1371_wait_src_ready
> (snd_es1371_src_read)
> 00000001 0.578ms (+0.015ms): snd_es1371_wait_src_ready
> (snd_es1371_src_read)
> 00000001 0.585ms (+0.006ms): snd_es1371_src_write (snd_es1371_dac1_rate)
> 00000001 0.585ms (+0.000ms): snd_es1371_wait_src_ready
> (snd_es1371_src_write)
> 00000001 0.601ms (+0.015ms): snd_es1371_src_write (snd_es1371_dac1_rate)
> 00000001 0.601ms (+0.000ms): snd_es1371_wait_src_ready
> (snd_es1371_src_write)
> 00000001 0.602ms (+0.001ms): snd_es1371_wait_src_ready
> (snd_es1371_dac1_rate)
> 00000001 0.616ms (+0.013ms): smp_apic_timer_interrupt
> (snd_ensoniq_playback1_prepare)
>
> or
>
> latency: 663 us, entries: 41 (41)
> -----------------
> | task: latencytest/11492, uid:0 nice:0 policy:1 rt_prio:99
> -----------------
> => started at: snd_ensoniq_playback1_prepare+0x74/0x180
> => ended at: snd_ensoniq_playback1_prepare+0x11d/0x180
> =======>
> 00000001 0.000ms (+0.000ms): snd_ensoniq_playback1_prepare
> (snd_pcm_do_prepare)
> 00000001 0.004ms (+0.004ms): snd_es1371_dac1_rate
> (snd_ensoniq_playback1_prepare)
> 00000001 0.005ms (+0.000ms): snd_es1371_wait_src_ready
> (snd_es1371_dac1_rate)
> 00000001 0.006ms (+0.001ms): snd_es1371_src_read (snd_es1371_dac1_rate)
> 00000001 0.006ms (+0.000ms): snd_es1371_wait_src_ready
> (snd_es1371_src_read)
> 00000001 0.019ms (+0.012ms): snd_es1371_wait_src_ready
> (snd_es1371_src_read)
> 00000001 0.607ms (+0.588ms): snd_es1371_src_write (snd_es1371_dac1_rate)
> 00000001 0.608ms (+0.000ms): snd_es1371_wait_src_ready
> (snd_es1371_src_write)
> 00000001 0.624ms (+0.016ms): snd_es1371_src_write (snd_es1371_dac1_rate)
> 00000001 0.624ms (+0.000ms): snd_es1371_wait_src_ready
> (snd_es1371_src_write)
> 00000001 0.626ms (+0.001ms): snd_es1371_wait_src_ready
> (snd_es1371_dac1_rate)
> 00000001 0.639ms (+0.013ms): smp_apic_timer_interrupt
> (snd_ensoniq_playback1_prepare)

Hmm, looks like the es1371 takes ~0.5 ms to set the DAC rate. The ALSA
team would probably be able to help. Takashi, any ideas?

Lee

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