lkml.org 
[lkml]   [2008]   [Mar]   [23]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
DateSun, 23 Mar 2008 07:38:42 +0100
FromManfred Spraul <>
SubjectRe: Scalability requirements for sysv ipc
Mike Galbraith wrote:
> On Sat, 2008-03-22 at 15:22 +0100, Manfred Spraul wrote:
> 
>> Mike Galbraith wrote:
>> 
>>> Total: 4691827                                Total: 3942000
>>> 
>>> 
>> Thanks. Unfortunately the test was buggy, it bound the tasks to the 
>> wrong cpu :-(
>> Could you run it again? Actually 1 cpu and 4 cpus are probably enough.
>> 
>
> Sure.  (ran as before, hopefully no transcription errors)
>
> 
Thanks:
sysv sem:
- 2.6.22 had almost linear scaling (up to 4 cores).
- 2.6.24.3 scales to 2 cpus, then it collapses. with 4 cores, it's 75% 
slower than 2.6.22.

sysv msg:
- neither 2.6.22 nor 2.6.24 scale very good. That's more or less 
expected, the message queue code contains a few global statistic 
counters (msg_hdrs, msg_bytes).

The cleanup of sysv is nice, but IMHO sysv sem should remain scalable - 
and a gloal semaphore with IDR can't be as scalable as the RCU protected 
array that was used before.

--
    Manfred
--
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: 2008-03-23 07:41    [from the cache]
©2003-2008