From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752512Ab2AZKDl (ORCPT ); Thu, 26 Jan 2012 05:03:41 -0500 Received: from mail-ee0-f46.google.com ([74.125.83.46]:33004 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751449Ab2AZKD2 (ORCPT ); Thu, 26 Jan 2012 05:03:28 -0500 From: Gilad Ben-Yossef 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 , Michal Nazarewicz , Kosaki Motohiro , Milton Miller Subject: [v7 8/8] mm: add vmstat counters for tracking PCP drains Date: Thu, 26 Jan 2012 12:02:01 +0200 Message-Id: <1327572121-13673-9-git-send-email-gilad@benyossef.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1327572121-13673-1-git-send-email-gilad@benyossef.com> References: <1327572121-13673-1-git-send-email-gilad@benyossef.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces two new vmstat counters for testing purposes: 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 CC: Michal Nazarewicz CC: Kosaki Motohiro CC: Milton Miller --- include/linux/vm_event_item.h | 1 + mm/page_alloc.c | 5 +++++ mm/vmstat.c | 2 ++ 3 files changed, 8 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 4135983..1aa9031 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1195,6 +1195,11 @@ 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 f600557..3ee5f99 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