2012/1/3 KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxx>: > (1/2/12 5:24 AM), Gilad Ben-Yossef wrote: >> This patch introduces two new vmstat counters: pcp_global_drain >> that counts the number of times a per-cpu pages global drain was >> requested and pcp_global_ipi_saved that counts the number of times >> the number of CPUs with per-cpu pages in any zone were less then >> 1/2 of the number of online CPUs. >> >> The patch purpose is to show the usefulness of only sending an IPI >> asking to drain per-cpu pages to CPUs that actually have them >> instead of a blind global IPI. It is probably not useful by itself. ... } >> on_each_cpu_mask(cpus_with_pcps, drain_local_pages, NULL, 1); >> + >> + count_vm_event(PCP_GLOBAL_DRAIN); >> + if (cpumask_weight(cpus_with_pcps)< (cpumask_weight(cpu_online_mask) / 2)) >> + count_vm_event(PCP_GLOBAL_IPI_SAVED); > > NAK. > > PCP_GLOBAL_IPI_SAVED is only useful at development phase. I can't > imagine normal admins use it. As the description explains, the purpose of the patch is to show why i claim the previous patch is useful. I did not meant it to be applied to mainline. My apologies for not stating this more clearly. I agree it is not useful for an admin, although perhaps PCP_GLOBAL_DRAIN alone might - I am not sure? Gilad -- Gilad Ben-Yossef Chief Coffee Drinker gilad@xxxxxxxxxxxxx Israel Cell: +972-52-8260388 US Cell: +1-973-8260388 http://benyossef.com "Unfortunately, cache misses are an equal opportunity pain provider." -- Mike Galbraith, LKML -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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