Re: [patch] voluntary-preempt-2.6.8-rc3-O4

Florian Schmidt
2004-08-09T16:53:28Z

On Mon, 9 Aug 2004 15:05:58 +0200
Ingo Molnar <mingo@elte.hu> wrote:

>
> * Ingo Molnar <mingo@elte.hu> wrote:
>
> > (the APIC bug has not been found yet so either turn off all APIC
> > options in .config or use noapic if you intend to use
> > voluntary_preempt=3.)
>
> but it would be nice if those experiencing APIC lockups could test the
> following: does the lockup still occur with -O4 if
> kernel_preemption=0?(while keeping voluntary_preemption=3)

I don't use APIC, since it never worked good for me.. But i wanted to
report that the mlockall latency still seems to be there.. I can easily
trigger it with mlockall'ing > ~10000kb. Need to recompile with the
preempt-timing patch, but here's an xrun trace that happened when
mlockall'ing 20000kb:

Aug 9 18:53:51 mango kernel: ALSA sound/core/pcm_lib.c:169: XRUN:
pcmC0D0p
Aug 9 18:53:51 mango kernel: [<c010636e>] dump_stack+0x1e/0x20
Aug 9 18:53:51 mango kernel: [<f08befae>]
snd_pcm_period_elapsed+0x2ee/0x460 [snd_pcm]
Aug 9 18:53:51 mango kernel: [<f08e1b84>]
snd_cs46xx_interrupt+0x1b4/0x1f0 [snd_cs46xx]
Aug 9 18:53:51 mango kernel: [<c011a5db>]
generic_handle_IRQ_event+0x3b/0x70
Aug 9 18:53:51 mango kernel: [<c0107725>] do_IRQ+0xa5/0x150
Aug 9 18:53:51 mango kernel: [<c0105f88>] common_interrupt+0x18/0x20
Aug 9 18:53:51 mango kernel: [<c013cc4a>] get_user_pages+0xca/0x380
Aug 9 18:53:51 mango kernel: [<c013e33d>] make_pages_present+0x8d/0xb0
Aug 9 18:53:51 mango kernel: [<c013e7e6>] mlock_fixup+0xa6/0xc0
Aug 9 18:53:51 mango kernel: [<c013eadb>] do_mlockall+0x7b/0x90
Aug 9 18:53:51 mango kernel: [<c013eb8e>] sys_mlockall+0x9e/0xb0
Aug 9 18:53:51 mango kernel: [<c0105e1b>] syscall_call+0x7/0xb

I can also see some of these [sparse they are though]:

Aug 9 18:58:08 mango kernel: ALSA sound/core/pcm_lib.c:199: Unexpected
hw_pointer value [1] (stream = 0, delta: -32, max jitter = 64): wrong
interrupt acknowledge?
Aug 9 18:58:08 mango kernel: [<c010636e>] dump_stack+0x1e/0x20
Aug 9 18:58:08 mango kernel: [<f08bee8d>]
snd_pcm_period_elapsed+0x1cd/0x460 [snd_pcm]
Aug 9 18:58:08 mango kernel: [<f08e1b84>]
snd_cs46xx_interrupt+0x1b4/0x1f0 [snd_cs46xx]
Aug 9 18:58:08 mango kernel: [<c011a5db>]
generic_handle_IRQ_event+0x3b/0x70
Aug 9 18:58:08 mango kernel: [<c0107725>] do_IRQ+0xa5/0x150
Aug 9 18:58:08 mango kernel: [<c0105f88>] common_interrupt+0x18/0x20

Flo

--
Palimm Palimm!