Messages in this thread | | | Date | Tue, 3 Jan 2012 21:00:17 +0200 | Subject | Re: [PATCH v5 8/8] mm: add vmstat counters for tracking PCP drains | From | Gilad Ben-Yossef <> |
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2012/1/3 KOSAKI Motohiro <kosaki.motohiro@gmail.com>: > (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@benyossef.com Israel Cell: +972-52-8260388 US Cell: +1-973-8260388 http://benyossef.com
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