Messages in this thread | | | Date | Mon, 26 Apr 1999 22:19:31 +0200 (CEST) | From | Ingo Molnar <> | Subject | Re: Linus on Linux, Apache and Threads |
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On Mon, 26 Apr 1999, Stephen C. Tweedie wrote:
> > That isnt the performance issue. The scaling issue tends to be the > > "wake all / wake one" stuff - which is hard to do well for wake one. > > SysV semaphores do wake-one for simple up/down counted use. The 2.2.6 > implementation does have a couple of problems right now: it will _only_ > wake one at a time even if you up() more than once, and it will do so in > strict FIFO, which is not necessarily going to direct the wakeup to the > best thread (ie. the one last scheduled on a CPU which is now idle).
i dont think this is a RL issue, most SysV semaphores (in SAP and Oracle) are mutexes.
-- mingo
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