From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx194.postini.com [74.125.245.194]) by kanga.kvack.org (Postfix) with SMTP id 269646B0031 for ; Wed, 4 Sep 2013 23:07:11 -0400 (EDT) Message-ID: <5227F4B6.40009@huawei.com> Date: Thu, 5 Sep 2013 11:04:22 +0800 From: Jianguo Wu MIME-Version: 1.0 Subject: Re: [PATCH] mm/thp: fix comments in transparent_hugepage_flags References: <1378301422-9468-1-git-send-email-wujianguo@huawei.com> <5227e870.ab42320a.62d4.3d12SMTPIN_ADDED_BROKEN@mx.google.com> In-Reply-To: <5227e870.ab42320a.62d4.3d12SMTPIN_ADDED_BROKEN@mx.google.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Wanpeng Li Cc: Jianguo Wu , akpm@linux-foundation.org, aarcange@redhat.com, kirill.shutemov@linux.intel.com, mgorman@suse.de, xiaoguangrong@linux.vnet.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Hi Wanpeng, On 2013/9/5 10:11, Wanpeng Li wrote: > Hi Jianguo, > On Wed, Sep 04, 2013 at 09:30:22PM +0800, Jianguo Wu wrote: >> Since commit d39d33c332(thp: enable direct defrag), defrag is enable >> for all transparent hugepage page faults by default, not only in >> MADV_HUGEPAGE regions. >> >> Signed-off-by: Jianguo Wu >> --- >> mm/huge_memory.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index a92012a..abf047e 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -28,10 +28,8 @@ >> >> /* >> * By default transparent hugepage support is enabled for all mappings > > This is also stale. TRANSPARENT_HUGEPAGE_ALWAYS is not configured by default in > order that avoid to risk increase the memory footprint of applications w/o a > guaranteed benefit. > Right, how about this: By default transparent hugepage support is disabled in order that avoid to risk increase the memory footprint of applications w/o a guaranteed benefit, and khugepaged scans all mappings when transparent hugepage enabled. Defrag is invoked by khugepaged hugepage allocations and by page faults for all hugepage allocations. Thanks, Jianguo Wu > Regards, > Wanpeng Li > >> - * and khugepaged scans all mappings. Defrag is only invoked by >> - * khugepaged hugepage allocations and by page faults inside >> - * MADV_HUGEPAGE regions to avoid the risk of slowing down short lived >> - * allocations. >> + * and khugepaged scans all mappings. Defrag is invoked by khugepaged >> + * hugepage allocations and by page faults for all hugepage allocations. >> */ >> unsigned long transparent_hugepage_flags __read_mostly = >> #ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS >> -- >> 1.8.1.2 >> >> -- >> 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 > > -- > 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 > > -- 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