13 Jul
2004
13 Jul
'04
5:55 p.m.
On Tue, 2004-07-13 at 09:26, Benno Senoner wrote:
Lee Revell wrote:
Right, I did not think of these. I just meant that you would not
typically run Gnutella on a DAW. This should never interfere with audio
latency, as Gnutella is running at normal priority and JACK is running
SCHED_FIFO.
Besides, it looks like there is a real problem with the route cache
flushing. I ran the same test with no significant network traffic and I
am still seeing spikes in latency. There are all of 5 entries in the
route cache.
Kernel IP routing cache
Source Destination Gateway Flags Metric Ref Use Iface
vmail-mx.dca.ne 192.168.2.102 192.168.2.102 l 0 1 838 lo
192.168.2.102 vmail-mx.dca.ne . 0 0 4 eth0
vmail-mx.dca.ne 192.168.2.102 192.168.2.102 l 0 1 838 lo
192.168.2.102 . . 0 0 2 eth0
192.168.2.102 vmail-mx.dca.ne . 0 0 4 eth0
Jul 13 15:15:49 mindpipe kernel: ALSA
/usr/src/alsa-cvs-1.0.5/alsa-driver/alsa-kernel/core/pcm_lib.c:169: XRUN: pcmC0D0p
Jul 13 15:15:49 mindpipe kernel: [__crc_totalram_pages+1387264/5353478]
snd_pcm_period_elapsed+0x2ca/0x410 [snd_pcm]
Jul 13 15:15:49 mindpipe kernel: [__crc_totalram_pages+1455070/5353478]
snd_emu10k1_interrupt+0x3c8/0x480 [snd_emu10k1]
Jul 13 15:15:49 mindpipe kernel: [handle_IRQ_event+49/96] handle_IRQ_event+0x31/0x60
Jul 13 15:15:49 mindpipe kernel: [do_IRQ+155/352] do_IRQ+0x9b/0x160
Jul 13 15:15:49 mindpipe kernel: [common_interrupt+24/32] common_interrupt+0x18/0x20
Jul 13 15:15:49 mindpipe kernel: [rt_run_flush+77/144] rt_run_flush+0x4d/0x90
Jul 13 15:15:49 mindpipe kernel: [rt_secret_rebuild+0/48] rt_secret_rebuild+0x0/0x30
Jul 13 15:15:49 mindpipe kernel: [rt_secret_rebuild+14/48] rt_secret_rebuild+0xe/0x30
Jul 13 15:15:49 mindpipe kernel: [run_timer_softirq+201/416]
run_timer_softirq+0xc9/0x1a0
Jul 13 15:15:49 mindpipe kernel: [__do_softirq+131/144] __do_softirq+0x83/0x90
Jul 13 15:15:49 mindpipe kernel: [do_softirq+53/64] do_softirq+0x35/0x40
Jul 13 15:15:49 mindpipe kernel: [do_IRQ+261/352] do_IRQ+0x105/0x160
Jul 13 15:15:49 mindpipe kernel: [common_interrupt+24/32] common_interrupt+0x18/0x20
Jul 13 15:15:49 mindpipe kernel: [default_idle+35/64] default_idle+0x23/0x40
Jul 13 15:15:49 mindpipe kernel: [apm_cpu_idle+165/384] apm_cpu_idle+0xa5/0x180
Jul 13 15:15:49 mindpipe kernel: [cpu_idle+45/64] cpu_idle+0x2d/0x40
Jul 13 15:15:49 mindpipe kernel: [start_kernel+392/464] start_kernel+0x188/0x1d0
Jul 13 15:15:49 mindpipe kernel:
Jul 13 15:25:49 mindpipe kernel: ALSA
/usr/src/alsa-cvs-1.0.5/alsa-driver/alsa-kernel/core/pcm_lib.c:169: XRUN: pcmC0D0p
Jul 13 15:25:49 mindpipe kernel: [__crc_totalram_pages+1387264/5353478]
snd_pcm_period_elapsed+0x2ca/0x410 [snd_pcm]
Jul 13 15:25:49 mindpipe kernel: [__crc_totalram_pages+1455070/5353478]
snd_emu10k1_interrupt+0x3c8/0x480 [snd_emu10k1]
Jul 13 15:25:49 mindpipe kernel: [handle_IRQ_event+49/96] handle_IRQ_event+0x31/0x60
Jul 13 15:25:49 mindpipe kernel: [do_IRQ+155/352] do_IRQ+0x9b/0x160
Jul 13 15:25:49 mindpipe kernel: [common_interrupt+24/32] common_interrupt+0x18/0x20
Jul 13 15:25:49 mindpipe kernel: [local_bh_enable+17/112] local_bh_enable+0x11/0x70
Jul 13 15:25:49 mindpipe kernel: [rt_run_flush+92/144] rt_run_flush+0x5c/0x90
Jul 13 15:25:49 mindpipe kernel: [rt_secret_rebuild+0/48] rt_secret_rebuild+0x0/0x30
Jul 13 15:25:49 mindpipe kernel: [rt_secret_rebuild+14/48] rt_secret_rebuild+0xe/0x30
Jul 13 15:25:49 mindpipe kernel: [run_timer_softirq+201/416]
run_timer_softirq+0xc9/0x1a0
Jul 13 15:25:49 mindpipe kernel: [__do_softirq+131/144] __do_softirq+0x83/0x90
Jul 13 15:25:49 mindpipe kernel: [do_softirq+53/64] do_softirq+0x35/0x40
Jul 13 15:25:49 mindpipe kernel: [do_IRQ+261/352] do_IRQ+0x105/0x160
Jul 13 15:25:49 mindpipe kernel: [common_interrupt+24/32] common_interrupt+0x18/0x20
Jul 13 15:25:49 mindpipe kernel: [default_idle+35/64] default_idle+0x23/0x40
Jul 13 15:25:49 mindpipe kernel: [apm_cpu_idle+165/384] apm_cpu_idle+0xa5/0x180
Jul 13 15:25:49 mindpipe kernel: [cpu_idle+45/64] cpu_idle+0x2d/0x40
Jul 13 15:25:49 mindpipe kernel: [start_kernel+392/464] start_kernel+0x188/0x1d0
Jul 13 15:25:49 mindpipe kernel:
On Mon, 2004-07-12 at 19:31, Andrew Morton wrote:
Why not reasonable ? It is very important that networking and HD I/O
both don't interfere with low latency audio.
Think about large audio setups where you use PC hardware to act as
dedicated samplers, software synthesizers etc.
OK, thanks. The problem areas there are the timer-based route cache
flushing and reiserfs.
We can probably fix the route caceh thing by rescheduling the timer after
having handled 1000 routes or whatever, although I do wonder if this is a
thing we really need to bother about - what else was that machine up to?
Gnutella client. Forgot about that. I agree, it is not reasonable to
expect low latency with this kind of network traffic happening. I am
impressed it worked as well as it did.