From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93DBBC433E1 for ; Thu, 14 May 2020 14:29:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2A61A206A5 for ; Thu, 14 May 2020 14:28:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="BMf5ILAu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2A61A206A5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6A925900005; Thu, 14 May 2020 10:28:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 633338E0005; Thu, 14 May 2020 10:28:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4FA0A900005; Thu, 14 May 2020 10:28:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0151.hostedemail.com [216.40.44.151]) by kanga.kvack.org (Postfix) with ESMTP id 33B518E0005 for ; Thu, 14 May 2020 10:28:59 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id CD5F42491 for ; Thu, 14 May 2020 14:28:58 +0000 (UTC) X-FDA: 76815556356.12.touch78_4e53d53b9aa19 X-HE-Tag: touch78_4e53d53b9aa19 X-Filterd-Recvd-Size: 5780 Received: from hqnvemgate24.nvidia.com (hqnvemgate24.nvidia.com [216.228.121.143]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Thu, 14 May 2020 14:28:58 +0000 (UTC) Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 07:26:39 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 14 May 2020 07:28:56 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 14 May 2020 07:28:56 -0700 Received: from [10.2.172.156] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 14:28:55 +0000 From: Zi Yan To: Anshuman Khandual CC: , Andrew Morton , "Kirill A. Shutemov" , Subject: Re: [RFC] mm/vmstat: Add events for THP migration without split Date: Thu, 14 May 2020 10:28:53 -0400 X-Mailer: MailMate (1.13.1r5685) Message-ID: <67C72AD3-120C-4825-B67B-AECD4245EC4E@nvidia.com> In-Reply-To: <1589257372-29576-1-git-send-email-anshuman.khandual@arm.com> References: <1589257372-29576-1-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL105.nvidia.com (172.20.187.12) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: multipart/signed; boundary="=_MailMate_CCB29A76-A65E-4F13-92D6-59BC5B189DEC_="; micalg=pgp-sha512; protocol="application/pgp-signature" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589466399; bh=OGgSR5gx2J6NyZmuHH/rWO4iXUFj+kkkfJWi2YkP9jc=; h=X-PGP-Universal:From:To:CC:Subject:Date:X-Mailer:Message-ID: In-Reply-To:References:MIME-Version:X-Originating-IP: X-ClientProxiedBy:Content-Type; b=BMf5ILAuRsX0OduG1sqZnhNAIRPq1gAK1FJmBU6AkOJDFqFpdysAFRk5LMLrximJz bNAVrYKUNUd9/TgCA8H7a7ymoz4xHMyvAj0mjdvdENTPaAqtBCS7jBDtGA2XyzQjmc Gve5RYhNIrk7MAlWrFsXXAd1AVdjZ1BKhf+5z23Nco78hdzfLP5V0bX3nkqHvppgbV 08qFzgs7ESSHJ96c9saFbak8wCbVzv/EuICxTYBe8P5Rx7GRRMaFsVW2FLgAlisEcU vrWHm6SPC1YcNl0/dXyr/Akr/UP29fUQOAm51uP05es0C1c9bLw8l4z3Bc1BVvpihZ G2sfTbUi93b9g== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: --=_MailMate_CCB29A76-A65E-4F13-92D6-59BC5B189DEC_= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On 12 May 2020, at 0:22, Anshuman Khandual wrote: > Add the following new trace events which will help in validating migrat= ion > events involving PMD based THP pages. > > 1. THP_PMD_MIGRATION_ENTRY_SET > 2. THP_PMD_MIGRATION_ENTRY_REMOVE > > There are no clear method to confirm whether a THP migration happened w= ith > out involving it's split. These trace events along with PGMIGRATE_SUCCE= SS > and PGMIGRATE_FAILURE will provide additional insights. After this chan= ge, > > A single 2M THP (2K base page) when migrated > > 1. Without split > > ................ > pgmigrate_success 1 > pgmigrate_fail 0 > ................ > thp_pmd_migration_entry_set 1 > thp_pmd_migration_entry_remove 1 > ................ > > 2. With split > > ................ > pgmigrate_success 512 > pgmigrate_fail 0 > ................ > thp_pmd_migration_entry_set 0 > thp_pmd_migration_entry_remove 0 > ................ > > pgmigrate_success as 1 instead of 512, provides a hint for possible THP= > migration event. But then it gets mixed with normal page migrations ove= r > time. These additional trace events provide required co-relation. To track successful THP migrations, the code below should work, right? diff --git a/mm/migrate.c b/mm/migrate.c index b1092876e537..d394f5331288 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1220,6 +1220,8 @@ static ICE_noinline int unmap_and_move(new_page_t g= et_new_page, * we want to retry. */ if (rc =3D=3D MIGRATEPAGE_SUCCESS) { + if (PageTransHuge(newpage)) + count_vm_event(THP_PMD_MIGRATION_SUCCESS); put_page(page); if (reason =3D=3D MR_MEMORY_FAILURE) { /* Maybe you could give more details on why you want to add the THP migratio= n event and how you are going to use the event in your use case. That would be very h= elpful to this code review. Are you going to do anything if you see THP migration failur= es? Thanks. =E2=80=94 Best Regards, Yan Zi --=_MailMate_CCB29A76-A65E-4F13-92D6-59BC5B189DEC_= Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQJDBAEBCgAtFiEEh7yFAW3gwjwQ4C9anbJR82th+ooFAl69VaUPHHppeUBudmlk aWEuY29tAAoJEJ2yUfNrYfqKl+kP/RvAsnjpBdzFa4nok58lz5bwn+wwXw+LmbBm qXOUo6mTy5zfB7MpB07loMJm9rh9PsBGbmMlUL3fuchA2UofWs6PU0VwydJUto6v YDyxj3/Wd5gd65wkEtNjQziQ5y2t5dEXDDX63HW5drbJPG6VR1AKAAwxhYfRw5Ao cjeJS1hFvplf/SX4sZEOaqoc/b72V5mq4fJ4eDQk0h2GKDI0S4rkYn1MYvYFziuc vScp76N6tFP3k7LRxoWNftW7iE8xP3oIE98xS0k7lPr1TCIo0s9SDf/wwJTMp2+p UvmTemGIwGuIkTqTjsNEmyeoEYv0dC4xl71i8fAJX0ms3VEy+apKxH2RNGGfKIxG M5iRuM1Ar+4b+S17GCKUgkb6BgbTsm1kiKa8+9V6B10M7LKLFpRQNioeidv+77qi yqs+d38Y75b1w8ZklJ3b2mKHSukbmsPs0F8MiKlgr3USxGx6XqNRa6ZNBFgyddVj BTkSrsyPPcWabYkwt4gGTd9RRKM4NHgeLG9FDAm+QK2bZJLrTpZgMivYbKfjkUct zqzQHIthMrkXQ7kTWCHhO1BE6wLdW2naClzkIvQMxjDPeoxlKuaB0Xj0q3EKfR3K 0sUkRyOJ0BMc22frfiDR0QQgouTIevQg94meTIic5nqNDU+fB6W97f1ksL/cU2cO CtfSXJlC =iRZb -----END PGP SIGNATURE----- --=_MailMate_CCB29A76-A65E-4F13-92D6-59BC5B189DEC_=--