From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx121.postini.com [74.125.245.121]) by kanga.kvack.org (Postfix) with SMTP id 022A76B0044 for ; Wed, 26 Sep 2012 21:17:41 -0400 (EDT) Received: by padfa10 with SMTP id fa10so1020966pad.14 for ; Wed, 26 Sep 2012 18:17:41 -0700 (PDT) Date: Wed, 26 Sep 2012 18:17:39 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH v4] kpageflags: fix wrong KPF_THP on non-huge compound pages In-Reply-To: <1348691234-31729-1-git-send-email-n-horiguchi@ah.jp.nec.com> Message-ID: References: <1348691234-31729-1-git-send-email-n-horiguchi@ah.jp.nec.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: Wu Fengguang , Andrew Morton , KOSAKI Motohiro , Andi Kleen , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Wed, 26 Sep 2012, Naoya Horiguchi wrote: > diff --git v3.6-rc6.orig/fs/proc/page.c v3.6-rc6/fs/proc/page.c > index 7fcd0d6..b8730d9 100644 > --- v3.6-rc6.orig/fs/proc/page.c > +++ v3.6-rc6/fs/proc/page.c > @@ -115,7 +115,13 @@ u64 stable_page_flags(struct page *page) > u |= 1 << KPF_COMPOUND_TAIL; > if (PageHuge(page)) > u |= 1 << KPF_HUGE; > - else if (PageTransCompound(page)) > + /* > + * PageTransCompound can be true for non-huge compound pages (slab > + * pages or pages allocated by drivers with __GFP_COMP) because it > + * just checks PG_head/PG_tail, so we need to check PageLRU to make > + * sure a given page is a thp, not a non-huge compound page. > + */ > + else if (PageTransCompound(page) && PageLRU(compound_trans_head(page))) > u |= 1 << KPF_THP; > > /* Yes, that looks good. Nice catch by Fengguang. -- 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