lkml.org 
[lkml]   [2004]   [Aug]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch] Latency Tracer, voluntary-preempt-2.6.8-rc4-O6

* Andi Kleen <ak@muc.de> wrote:

> >> Interesting results. One of the problems is kallsyms_lookup,
> >> triggered by the printks:
> >
> > yeah - kallsyms_lookup does a linear search over thousands of symbols.
> > Especially since /proc/latency_trace uses it too it would be worthwile
> > to implement some sort of binary searching.
>
> Or just stick some cond_sched()s in there. It was designed to be slow,
> but there are no locking issues.

the speedup would be important: even on a 2GHz box reading 10,000 trace
entries takes a couple of seconds.

[ the /proc/latency_trace read()ing itself is fully preemptible, i'd be
ashamed if it werent ;) ]

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/

\
 
 \ /
  Last update: 2005-03-22 14:05    [W:0.071 / U:0.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site