From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx181.postini.com [74.125.245.181]) by kanga.kvack.org (Postfix) with SMTP id F0D066B005C for ; Tue, 9 Apr 2013 19:29:06 -0400 (EDT) Received: from /spool/local by e34.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 9 Apr 2013 17:29:04 -0600 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id 9B49D19D8036 for ; Tue, 9 Apr 2013 17:28:42 -0600 (MDT) Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r39NSknu366852 for ; Tue, 9 Apr 2013 17:28:46 -0600 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r39NSkoZ007076 for ; Tue, 9 Apr 2013 17:28:46 -0600 From: Cody P Schafer Subject: [PATCH v2 04/10] mm/page_alloc: convert zone_pcp_update() to rely on memory barriers instead of stop_machine() Date: Tue, 9 Apr 2013 16:28:13 -0700 Message-Id: <1365550099-6795-5-git-send-email-cody@linux.vnet.ibm.com> In-Reply-To: <1365550099-6795-1-git-send-email-cody@linux.vnet.ibm.com> References: <1365550099-6795-1-git-send-email-cody@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Gilad Ben-Yossef , Simon Jeons , KOSAKI Motohiro , Mel Gorman , Linux MM , LKML , Cody P Schafer zone_pcp_update()'s goal is to adjust the ->high and ->mark members of a percpu pageset based on a zone's ->managed_pages. We don't need to drain the entire percpu pageset just to modify these fields. This lets us avoid calling setup_pageset() (and the draining required to call it) and instead allows simply setting the fields' values (with some attention paid to memory barriers to prevent the relationship between ->batch and ->high from being thrown off). This does change the behavior of zone_pcp_update() as the percpu pagesets will not be drained when zone_pcp_update() is called (they will end up being shrunk, not completely drained, later when a 0-order page is freed in free_hot_cold_page()). Signed-off-by: Cody P Schafer --- mm/page_alloc.c | 33 +++++++++------------------------ 1 file changed, 9 insertions(+), 24 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a07bd4c..4a03c56 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6012,33 +6012,18 @@ void free_contig_range(unsigned long pfn, unsigned nr_pages) #endif #ifdef CONFIG_MEMORY_HOTPLUG -static int __meminit __zone_pcp_update(void *data) -{ - struct zone *zone = data; - int cpu; - unsigned long batch = zone_batchsize(zone), flags; - - for_each_possible_cpu(cpu) { - struct per_cpu_pageset *pset; - struct per_cpu_pages *pcp; - - pset = per_cpu_ptr(zone->pageset, cpu); - pcp = &pset->pcp; - - local_irq_save(flags); - if (pcp->count > 0) - free_pcppages_bulk(zone, pcp->count, pcp); - drain_zonestat(zone, pset); - setup_pageset(pset, batch); - local_irq_restore(flags); - } - return 0; -} - +/* + * The zone indicated has a new number of managed_pages; batch sizes and percpu + * page high values need to be recalulated. + */ void __meminit zone_pcp_update(struct zone *zone) { + unsigned cpu; + unsigned long batch; mutex_lock(&pcp_batch_high_lock); - stop_machine(__zone_pcp_update, zone, NULL); + batch = zone_batchsize(zone); + for_each_possible_cpu(cpu) + pageset_set_batch(per_cpu_ptr(zone->pageset, cpu), batch); mutex_unlock(&pcp_batch_high_lock); } #endif -- 1.8.2 -- 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/ . Don't email: email@kvack.org