On Wed, 2011-06-15 at 23:37 +0200, Peter Zijlstra wrote: > On Wed, 2011-06-15 at 14:12 -0700, Tim Chen wrote: > > Thanks to Andi for providing the info. We've used this workaround in > > our testing so it will not mask true kernel scaling bottlenecks. > > > http://programming.kicks-ass.net/sekrit/39-2.txt.bz2 > http://programming.kicks-ass.net/sekrit/tip-2.txt.bz2 > > tip+sirq+linus is still slightly faster than .39 here, although removing > that sysconf() wreckage closed the gap considerably (needing to know the > number of cpus to optimize locking sounds like a trainwreck all of its > own, needing it _that_ often instead of just once at startup is even > worse). > Peter, Fengguang's readahead fixes for tmpfs removed another bottleneck before anon_vma->lock become dominant. https://lkml.org/lkml/2011/4/26/143) We've found this issue when we were testing exim earlier. It was merged in 3.0-rc2 but not in plain 2.6.39. So with this patch on 2.6.39 we should get better comparison with 3.0-rc2. Thanks. Tim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>