memory-hotplug: allocate zone's pcp before onlining pages (6dcd73d7) · Commits · 戴 / test

We use __free_page() to put a page to buddy system when onlining pages. __free_page() will store NR_FREE_PAGES in zone's pcp.vm_stat_diff, so we should allocate zone's pcp before onlining pages, otherwise we will lose some free pages. [mhocko@suse.cz: make zone_pcp_reset independent of MEMORY_HOTREMOVE] Signed-off-by:

Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by:

Michal Hocko <mhocko@suse.cz> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/memory_hotplug.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -498,12 +498,16 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages)
		* So, zonelist must be updated after online.
		*/
		mutex_lock(&zonelists_mutex);
		if (!populated_zone(zone))
		if (!populated_zone(zone)) {
		need_zonelists_rebuild = 1;
		build_all_zonelists(NULL, zone);
		}

		ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
		online_pages_range);
		if (ret) {
		if (need_zonelists_rebuild)
		zone_pcp_reset(zone);
		mutex_unlock(&zonelists_mutex);
		printk(KERN_DEBUG "online_pages [mem %#010llx-%#010llx] failed\n",
		(unsigned long long) pfn << PAGE_SHIFT,
		@@ -519,7 +523,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages)
		if (onlined_pages) {
		node_set_state(zone_to_nid(zone), N_HIGH_MEMORY);
		if (need_zonelists_rebuild)
		build_all_zonelists(NULL, zone);
		build_all_zonelists(NULL, NULL);
		else
		zone_pcp_update(zone);
		}

mm/page_alloc.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -5983,7 +5983,6 @@ void __meminit zone_pcp_update(struct zone *zone)
		}
		#endif

		#ifdef CONFIG_MEMORY_HOTREMOVE
		void zone_pcp_reset(struct zone *zone)
		{
		unsigned long flags;
		@@ -6003,6 +6002,7 @@ void zone_pcp_reset(struct zone *zone)
		local_irq_restore(flags);
		}

		#ifdef CONFIG_MEMORY_HOTREMOVE
		/*
		* All pages in the range must be isolated before calling this.
		*/

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