Messages in this thread | | | Subject | Re: [patch] voluntary-preempt-2.6.8-rc2-I3 | From | Thomas Charbonnel <> | Date | Sat, 24 Jul 2004 01:48:43 +0200 |
| |
> All known performance problems have been fixed in -I4. The focus is > mainly on latency. You can best support this patch by trying it out and > doing measurements - both latency and throughput measurements are > welcome. Latency measurement can be done via the latencytest tool: > > http://www.alsa-project.org/~iwai/latencytest-0.5.4.tar.gz > > If you enable both CONFIG_PREEMPT_VOLUNTARY and CONFIG_PREEMPT then you > can use the /proc/sys/kernel/voluntary_preemption|kernel_preemption > sysctl knobs to turn the preemption features on/off. The following flag > combinations can be used to do comparisons: > > vanilla: vp:0 kp:0 > CONFIG_PREEMPT: vp:0 kp:1 > voluntary-preempt: vp:1 kp:0 > voluntary-preempt + CONFIG_PREEMPT: vp:1 kp:1 > voluntary-preempt + softirq defer: vp:2 kp:0 [default] > voluntary-preempt + softirq defer + CONFIG_PREEMPT: vp:2 kp:1 > > each of the above combinations should work and should pretty exactly > represent that particular kernel (i.e. you can get vanilla > non-preemptible 2.6.8-rc2 kernel behavior by switching both flags on) - > but i typically use the default one for testing. > > Ingo
Hi,
I'm experiencing hard freezes in the early stage of the latency test suite (X11 test, latencytest-0.5.4) with 2.6.8-rc2-I4, both with the default vp:2 kp:0 and with vp:0 kp:0 (nvidia card, xfree drivers). I was also experiencing hard freezes before with 2.6.7-mm7-H4 while doing intensive disk I/O on reiserfs (e.g. tar big_file.tar.gz)
As for the tests, I have 2 remaining problems, one with mmap in conjunction with mlockall(MCL_CURRENT|MCL_FUTURE) :
XRUN: pcmC2D0c [<c0105f6e>] dump_stack+0x1e/0x30 [<c03673b1>] snd_pcm_period_elapsed+0x2e1/0x420 [<c039d3d4>] snd_hdsp_interrupt+0x174/0x180 [<c01073bb>] handle_IRQ_event+0x3b/0x70 [<c0107746>] do_IRQ+0x96/0x150 [<c0105b14>] common_interrupt+0x18/0x20 [<c014890f>] do_no_page+0x5f/0x300 [<c0148da2>] handle_mm_fault+0xe2/0x190 [<c01477a0>] get_user_pages+0x130/0x370 [<c0148f17>] make_pages_present+0x87/0xb0 [<c014a916>] do_mmap_pgoff+0x476/0x6d0 [<c010ba50>] sys_mmap2+0xa0/0xe0 [<c0105155>] sysenter_past_esp+0x52/0x71 XRUN: pcmC2D0p [<c0105f6e>] dump_stack+0x1e/0x30 [<c03673b1>] snd_pcm_period_elapsed+0x2e1/0x420 [<c039d3b4>] snd_hdsp_interrupt+0x154/0x180 [<c01073bb>] handle_IRQ_event+0x3b/0x70 [<c0107746>] do_IRQ+0x96/0x150 [<c0105b14>] common_interrupt+0x18/0x20 [<c014890f>] do_no_page+0x5f/0x300 [<c0148da2>] handle_mm_fault+0xe2/0x190 [<c01477a0>] get_user_pages+0x130/0x370 [<c0148f17>] make_pages_present+0x87/0xb0 [<c014a916>] do_mmap_pgoff+0x476/0x6d0 [<c010ba50>] sys_mmap2+0xa0/0xe0 [<c0105155>] sysenter_past_esp+0x52/0x71
and the other one when accessing the keyboard at a sensible moment. Such a moment occurs rather precisely every 8.079 seconds on my system (+/- 2ms). I could verify this by keeping a key pressed (xrun every 8.079 second), or just using the keyboard normally (xruns happen more or less randomly but the time interval to the previous one is always a multiple of this 8.079 period) :
XRUN: pcmC2D0c [<c0105f6e>] dump_stack+0x1e/0x30 [<c03673b1>] snd_pcm_period_elapsed+0x2e1/0x420 [<c039d3d4>] snd_hdsp_interrupt+0x174/0x180 [<c01073bb>] handle_IRQ_event+0x3b/0x70 [<c0107746>] do_IRQ+0x96/0x150 [<c0105b14>] common_interrupt+0x18/0x20 [<c0107746>] do_IRQ+0x96/0x150 [<c0105b14>] common_interrupt+0x18/0x20 [<c01030f4>] cpu_idle+0x34/0x40 [<c054880d>] start_kernel+0x16d/0x190 [<c010019f>] 0xc010019f
Can you think of a possible explanation for this one ?
Thomas
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |