Messages in this thread | | | Date | Sun, 23 Mar 2008 07:38:42 +0100 | From | Manfred Spraul <> | Subject | Re: Scalability requirements for sysv ipc |
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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
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