From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx151.postini.com [74.125.245.151]) by kanga.kvack.org (Postfix) with SMTP id 324D36B006C for ; Mon, 2 Jan 2012 05:25:36 -0500 (EST) Received: by mail-ee0-f41.google.com with SMTP id c41so17353876eek.14 for ; Mon, 02 Jan 2012 02:25:35 -0800 (PST) From: Gilad Ben-Yossef Subject: [PATCH v5 8/8] mm: add vmstat counters for tracking PCP drains Date: Mon, 2 Jan 2012 12:24:19 +0200 Message-Id: <1325499859-2262-9-git-send-email-gilad@benyossef.com> In-Reply-To: <1325499859-2262-1-git-send-email-gilad@benyossef.com> References: <1325499859-2262-1-git-send-email-gilad@benyossef.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: Gilad Ben-Yossef , Christoph Lameter , Chris Metcalf , Peter Zijlstra , Frederic Weisbecker , linux-mm@kvack.org, Pekka Enberg , Matt Mackall , Sasha Levin , Rik van Riel , Andi Kleen , Mel Gorman , Andrew Morton , Alexander Viro , Avi Kivity 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. Signed-off-by: Gilad Ben-Yossef CC: Christoph Lameter CC: Chris Metcalf CC: Peter Zijlstra CC: Frederic Weisbecker CC: linux-mm@kvack.org CC: Pekka Enberg CC: Matt Mackall CC: Sasha Levin CC: Rik van Riel CC: Andi Kleen CC: Mel Gorman CC: Andrew Morton CC: Alexander Viro CC: Avi Kivity --- include/linux/vm_event_item.h | 1 + mm/page_alloc.c | 4 ++++ mm/vmstat.c | 2 ++ 3 files changed, 7 insertions(+), 0 deletions(-) diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h index 03b90cd..3657f6f 100644 --- a/include/linux/vm_event_item.h +++ b/include/linux/vm_event_item.h @@ -58,6 +58,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, THP_COLLAPSE_ALLOC_FAILED, THP_SPLIT, #endif + PCP_GLOBAL_DRAIN, PCP_GLOBAL_IPI_SAVED, NR_VM_EVENT_ITEMS }; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 092c331..4ca6bfa 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1140,6 +1140,10 @@ void drain_all_pages(void) cpumask_clear_cpu(cpu, cpus_with_pcps); } 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); } #ifdef CONFIG_HIBERNATION diff --git a/mm/vmstat.c b/mm/vmstat.c index 8fd603b..daf632c 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -786,6 +786,8 @@ const char * const vmstat_text[] = { "thp_collapse_alloc_failed", "thp_split", #endif + "pcp_global_drain", + "pcp_global_ipi_saved" #endif /* CONFIG_VM_EVENTS_COUNTERS */ }; -- 1.7.0.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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: email@kvack.org