On Tue, 2004-07-20 at 08:19, Jens Axboe wrote:
On Tue, Jul 20 2004, Ingo Molnar wrote:
How much
I/O do you allow to be in flight at once? It seems like by
decreasing the maximum size of I/O that you handle in one interrupt
you could improve this quite a bit. Disk throughput is good enough,
anyone in the real world who would feel a 10% hit would just throw
hardware at the problem.
i'm not sure whether this particular value (max # of sg-entries per IO
op) is runtime tunable. Jens? Might make sense to enable elvtune-alike
tunability of this value.
elvtune is long dead :-)
This one occured several times while bonnie was cleaning up after
itself:
ALSA /home/rlrevell/cvs/alsa/alsa-driver/alsa-kernel/core/pcm_lib.c:169:
XRUN: pcmC0D2c
[<c01066a7>] dump_stack+0x17/0x20
[<de935377>] snd_pcm_period_elapsed+0x2c7/0x400 [snd_pcm]
[<de945211>] snd_emu10k1_interrupt+0xd1/0x3c0 [snd_emu10k1]
[<c01078c3>] handle_IRQ_event+0x33/0x60
[<c0107c05>] do_IRQ+0xa5/0x170
[<c0106268>] common_interrupt+0x18/0x20
[<c0161b81>] shrink_dcache_parent+0x21/0x30
[<c0159d69>] d_unhash+0x39/0xb0
[<c0159e4c>] vfs_rmdir+0x6c/0x1b0
[<c015a05f>] sys_rmdir+0xcf/0xf0
[<c0106047>] syscall_call+0x7/0xb
ALSA /home/rlrevell/cvs/alsa/alsa-driver/alsa-kernel/core/pcm_lib.c:169:
XRUN: pcmC0D0p
[<c01066a7>] dump_stack+0x17/0x20
[<de935377>] snd_pcm_period_elapsed+0x2c7/0x400 [snd_pcm]
[<de945477>] snd_emu10k1_interrupt+0x337/0x3c0 [snd_emu10k1]
[<c01078c3>] handle_IRQ_event+0x33/0x60
[<c0107c05>] do_IRQ+0xa5/0x170
[<c0106268>] common_interrupt+0x18/0x20
[<c0161b81>] shrink_dcache_parent+0x21/0x30
[<c0159d69>] d_unhash+0x39/0xb0
[<c0159e4c>] vfs_rmdir+0x6c/0x1b0
[<c015a05f>] sys_rmdir+0xcf/0xf0
[<c0106047>] syscall_call+0x7/0xb
Lee