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

Lee Revell
2004-08-10T14:16:49Z

On Tue, 2004-08-10 at 03:53, Ingo Molnar wrote:
> can you trigger similar latencies via the attached mlock testcode?
> (written by Florian. Run it as root.)
>

Yup, using only 100000 bytes, I get a bunch of these:

(mlockall-test/6561): 10353us non-preemptible critical section violated 1100 us preempt threshold starting at get_user_pages+0xa6/0x3b0 and ending at get_user_pages+0x2c5/0x3b0
[<c0106717>] dump_stack+0x17/0x20
[<c0113eec>] dec_preempt_count+0x3c/0x50
[<c013d435>] get_user_pages+0x2c5/0x3b0
[<c013ea28>] make_pages_present+0x68/0x90
[<c013ee8d>] mlock_fixup+0x8d/0xb0
[<c013f170>] do_mlockall+0x70/0x90
[<c013f229>] sys_mlockall+0x99/0xa0
[<c01060b7>] syscall_call+0x7/0xb
ALSA /home/rlrevell/cvs/alsa/alsa-driver/alsa-kernel/core/pcm_lib.c:139: XRUN: pcmC0D2c
[<c0106717>] dump_stack+0x17/0x20
[<de93d64b>] snd_pcm_period_elapsed+0x27b/0x3e0 [snd_pcm]
[<de9791d1>] snd_emu10k1_interrupt+0xd1/0x3c0 [snd_emu10k1]
[<c011a7d3>] generic_handle_IRQ_event+0x33/0x60
[<c01079c2>] do_IRQ+0xb2/0x180
[<c01062d8>] common_interrupt+0x18/0x20
[<c0113d31>] check_preempt_timing+0x11/0xf0
[<c0113e62>] touch_preempt_timing+0x32/0x40
[<c013d216>] get_user_pages+0xa6/0x3b0
[<c013ea28>] make_pages_present+0x68/0x90
[<c013ee8d>] mlock_fixup+0x8d/0xb0
(mlockall-test/6561): 9168us non-preemptible critical section violated 1100 us preempt threshold starting at get_user_pages+0x2cf/0x3b0 and ending at get_user_pages+0xa6/0x3b0
[<c0106717>] dump_stack+0x17/0x20
[<c0113e62>] touch_preempt_timing+0x32/0x40
[<c013d216>] get_user_pages+0xa6/0x3b0
[<c013ea28>] make_pages_present+0x68/0x90
[<c013ee8d>] mlock_fixup+0x8d/0xb0
[<c013f170>] do_mlockall+0x70/0x90
[<c013f229>] sys_mlockall+0x99/0xa0
[<c01060b7>] syscall_call+0x7/0xb

Lee