On Fri, Aug 23, 2013 at 10:36:38AM -0400, Naoya Horiguchi wrote: >On Fri, Aug 23, 2013 at 06:30:39PM +0800, Wanpeng Li wrote: >> v1 -> v2: >> * add more explanation in patch description. >> >> Set pageblock migration type will hold zone->lock which is heavy contended >> in system to avoid race. However, soft offline page will set pageblock >> migration type twice during get page if the page is in used, not hugetlbfs >> page and not on lru list. There is unnecessary to set the pageblock migration >> type and hold heavy contended zone->lock again if the first round get page >> have already set the pageblock to right migration type. >> >> The trick here is migration type is MIGRATE_ISOLATE. There are other two parts >> can change MIGRATE_ISOLATE except hwpoison. One is memory hoplug, however, we >> hold lock_memory_hotplug() which avoid race. The second is CMA which umovable >> page allocation requst can't fallback to. So it's safe here. >> >> Signed-off-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx> >> --- >> mm/memory-failure.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >> index 297965e..f357c91 100644 >> --- a/mm/memory-failure.c >> +++ b/mm/memory-failure.c >> @@ -1426,7 +1426,8 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags) >> * was free. This flag should be kept set until the source page >> * is freed and PG_hwpoison on it is set. >> */ >> - set_migratetype_isolate(p, true); >> + if (get_pageblock_migratetype(p) == MIGRATE_ISOLATE) >> + set_migratetype_isolate(p, true); > >Do you really mean "we set MIGRATE_ISOLATE only if it's already set?" > Ouch, it's my fault, I will fix it in next version. ;-) Regards, Wanpeng Li >Thanks, >Naoya Horiguchi > >> /* >> * When the target page is a free hugepage, just remove it >> * from free hugepage list. >> -- >> 1.8.1.2 >> >> -- >> To unsubscribe, send a message with 'unsubscribe linux-mm' in >> the body to majordomo@xxxxxxxxx. For more info on Linux MM, >> see: http://www.linux-mm.org/ . >> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> >> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>