Messages in this thread |  | | Date | Sat, 14 Aug 2004 13:51:39 +0200 | | From | Ingo Molnar <> | | Subject | Re: [patch] Latency Tracer, voluntary-preempt-2.6.8-rc4-O6 |
| |
* James Courtier-Dutton <James@superbug.demon.co.uk> wrote:
> I have tested this for a day now, and I have noticed problems: > 1) > kernel syslog gets a record like this: > > (default.hotplug/1470): 121 us critical section violates 100 us > threshold.
> and the /proc/latency_trace gets: > > preemption latency trace v1.0 > > ----------------------------- > > latency: 121 us, entries: 1032 (1032) > > process: default.hotplug/1470, uid: 0 > > nice: -10, policy: 0, rt_priority: 0 > > =======> > > 0.000ms (+0.000ms): page_address (kmap_high) > > 0.000ms (+0.000ms): page_slot (page_address) > > 0.000ms (+0.000ms): flush_all_zero_pkmaps (kmap_high) > > 0.000ms (+0.000ms): set_page_address (flush_all_zero_pkmaps)
> Could the patch be adjusted to make the syslog and the > /proc/latency_trace produce the same output?
We cannot include the full trace in the syslog - it's possibly thousands of lines long.
> 2) > I suspect that there is a problem with reiserfs, but when I detect a > momentary hang in the system(mouse stops moving), no latency_trace appears.
well, the mouse could stop moving for a number of reasons. It's handled via the X server and if the X server is preempted (for whatever reason) then the mouse pointer isnt updated.
you could try to change the mouse IRQ to be non-threaded. Also, do you have kernel_preemption set to 1? It defaults to 0.
Ingo - 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/
|  |