Ingo Molnar <[EMAIL PROTECTED]> wrote: > > > * Andrew Morton <[EMAIL PROTECTED]> wrote: > > > I forget how much of the 1000% came from that, but it was quite a lot. > > > > Removing the BKL was the first step. That took the context switch > > rate under high load from ~10,000/sec up to ~300,000/sec. Because the > > first thing a CPU hit on entry to the fs was then a semaphore. > > Performance rather took a dive. > > > > Of course the locks also became much finer-grained, so the contention > > opportunities lessened. But j_list_lock and j_state_lock have fs-wide > > scope, so I'd expect the context switch rate to go up quite a lot > > again. > > > > The hold times are short, and a context switch hurts rather ore than a > > quick spin. > > which particular workload was this - dbench? (I can try PREEMPT_RT on an > 8-way, such effects will show up tenfold.) >
Oh gee, that was back in the days when Martin was being useful. SDET, I think. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
