From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx169.postini.com [74.125.245.169]) by kanga.kvack.org (Postfix) with SMTP id 557346B0031 for ; Thu, 12 Sep 2013 19:46:18 -0400 (EDT) Received: from /spool/local by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 13 Sep 2013 05:06:24 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 2DB90E0058 for ; Fri, 13 Sep 2013 05:16:59 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r8CNm7Sc29491200 for ; Fri, 13 Sep 2013 05:18:10 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r8CNk3od028257 for ; Fri, 13 Sep 2013 05:16:03 +0530 Date: Fri, 13 Sep 2013 07:46:01 +0800 From: Wanpeng Li Subject: Re: [PATCH] mm/hwpoison: move set_migratetype_isolate() outside get_any_page() Message-ID: <20130912234601.GA21487@hacker.(null)> Reply-To: Wanpeng Li References: <1378998704-d94o0a30-mutt-n-horiguchi@ah.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1378998704-d94o0a30-mutt-n-horiguchi@ah.jp.nec.com> Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: Andrew Morton , Andi Kleen , Fengguang Wu , Tony Luck , gong.chen@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu, Sep 12, 2013 at 11:11:44AM -0400, Naoya Horiguchi wrote: >Chen Gong pointed out that set/unset_migratetype_isolate() was done in >different functions in mm/memory-failure.c, which makes the code less >readable/maintenable. So this patch makes it done in soft_offline_page(). > >With this patch, we get to hold lock_memory_hotplug() longer but it's not >a problem because races between memory hotplug and soft offline are very rare. > >This patch is against next-20130910. > Reviewed-by: Wanpeng Li >Signed-off-by: Naoya Horiguchi >Reviewed-by: Chen, Gong >--- > mm/memory-failure.c | 36 +++++++++++++++++------------------- > 1 file changed, 17 insertions(+), 19 deletions(-) > >diff --git a/mm/memory-failure.c b/mm/memory-failure.c >index 947ed54..702e1e1 100644 >--- a/mm/memory-failure.c >+++ b/mm/memory-failure.c >@@ -1421,19 +1421,6 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags) > return 1; > > /* >- * The lock_memory_hotplug prevents a race with memory hotplug. >- * This is a big hammer, a better would be nicer. >- */ >- lock_memory_hotplug(); >- >- /* >- * Isolate the page, so that it doesn't get reallocated if it >- * was free. This flag should be kept set until the source page >- * is freed and PG_hwpoison on it is set. >- */ >- if (get_pageblock_migratetype(p) != MIGRATE_ISOLATE) >- set_migratetype_isolate(p, true); >- /* > * When the target page is a free hugepage, just remove it > * from free hugepage list. > */ >@@ -1453,7 +1440,6 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags) > /* Not a free page */ > ret = 1; > } >- unlock_memory_hotplug(); > return ret; > } > >@@ -1652,15 +1638,28 @@ int soft_offline_page(struct page *page, int flags) > } > } > >+ /* >+ * The lock_memory_hotplug prevents a race with memory hotplug. >+ * This is a big hammer, a better would be nicer. >+ */ >+ lock_memory_hotplug(); >+ >+ /* >+ * Isolate the page, so that it doesn't get reallocated if it >+ * was free. This flag should be kept set until the source page >+ * is freed and PG_hwpoison on it is set. >+ */ >+ if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) >+ set_migratetype_isolate(page, true); >+ > ret = get_any_page(page, pfn, flags); >- if (ret < 0) >- goto unset; >- if (ret) { /* for in-use pages */ >+ unlock_memory_hotplug(); >+ if (ret > 0) { /* for in-use pages */ > if (PageHuge(page)) > ret = soft_offline_huge_page(page, flags); > else > ret = __soft_offline_page(page, flags); >- } else { /* for free pages */ >+ } else if (ret == 0) { /* for free pages */ > if (PageHuge(page)) { > set_page_hwpoison_huge_page(hpage); > dequeue_hwpoisoned_huge_page(hpage); >@@ -1671,7 +1670,6 @@ int soft_offline_page(struct page *page, int flags) > atomic_long_inc(&num_poisoned_pages); > } > } >-unset: > unset_migratetype_isolate(page, MIGRATE_MOVABLE); > return ret; > } >-- >1.8.3.1 -- 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