On Fri, 3 Sep 2010 14:47:03 -0700 Ying Han <yinghan@xxxxxxxxxx> wrote: > > We don't have any quantitative data on the effect of these excess tlb > > flushes, which makes it difficult to decide which kernel versions > > should receive this patch. > > > > Help? > > Andrew: > > We observed the degradation on 2.6.34 compared to 2.6.26 kernel. The > workload we are running is doing 4k-random-write which runs about 3-4 > minutes. We captured the TLB shootsdowns before/after: > > Before the change: > TLB: 29435 22208 37146 25332 47952 43698 43545 40297 49043 44843 46127 > 50959 47592 46233 43698 44690 TLB shootdowns [HSUM = 662798 ] > > After the change: > TLB: 2340 3113 1547 1472 2944 4194 2181 1212 2607 4373 1690 1446 2310 > 3784 1744 1134 TLB shootdowns [HSUM = 38091 ] Do you have data on how much additional CPU time (and/or wall time) was consumed? > Also worthy to mention, we are running in fake numa system where each > fake node is 128M size. That makes differences on the check > inactive_anon_is_low() since the active/inactive ratio falls to 1. -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>