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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 96EDBC433B4 for ; Wed, 7 Apr 2021 21:41:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2CDB761205 for ; Wed, 7 Apr 2021 21:41:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CDB761205 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B299E6B0078; Wed, 7 Apr 2021 17:41:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AFF7C6B007D; Wed, 7 Apr 2021 17:41:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9A0A96B007E; Wed, 7 Apr 2021 17:41:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0095.hostedemail.com [216.40.44.95]) by kanga.kvack.org (Postfix) with ESMTP id 7DD9A6B0078 for ; Wed, 7 Apr 2021 17:41:09 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 40ACD181BDC91 for ; Wed, 7 Apr 2021 21:41:09 +0000 (UTC) X-FDA: 78006891858.30.B56BB05 Received: from mail-ej1-f46.google.com (mail-ej1-f46.google.com [209.85.218.46]) by imf13.hostedemail.com (Postfix) with ESMTP id B5EA9E000102 for ; Wed, 7 Apr 2021 21:41:06 +0000 (UTC) Received: by mail-ej1-f46.google.com with SMTP id e14so30035925ejz.11 for ; Wed, 07 Apr 2021 14:41:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=9SQ0hw9S+bPEMfp5AGgdbU/K5VN9SJhDyLuUFosgsgY=; b=ESHvBwnuUCFygLrjCnezEKDuoL+Hh4uXgo88Dp2LIkN5nmUE8680L3lZPgur65/3SE 5ZNfyhRfiPGtLknk5Tjxco4axiImqC+O/lqBsuMY3CUgKoO/X8MDppiL91tJlF5YzKFU 4K7NDpzVwc0dishcJoWXBoY17GZiz8/oX2P8hrIWyRAXc74nGeOr2NgGJzJASYZDsffD m1h3pNHs7MSV+oMoaxKLBOpSXhQGY18CxgjGOiprRzkX+9Z56FVNdlO+L9ZngzwSZQ+n KQSOFThhR5Q71KdvgJJ/4NGlrjVh1DJF2kyAQadGTstAE+uhE6jhqxa6HDvMsWQGGV36 FNuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=9SQ0hw9S+bPEMfp5AGgdbU/K5VN9SJhDyLuUFosgsgY=; b=QHlY/Ck1+l5AeOF5WmOmAejkB1D9fEqnGatw8JMHbJYb68ulRWduTbE6Dlr6vjsN7m w/6gq2JVFnRYH0WL0OkcE4+AnsKT7GVl90prKx1JrJt88cCUEXuT3fmoMu8JHaGfwOLt UIQgoBVYboEjk8/3YE1MsMz432pVqF2JTt2OurXbk7T5nEgaJg+ONNBOxeiiWEK4rqLq OrWeZxWBH5S5STdlhLlQxXXcXvh1RFLvwwLn1tZI14EIsm5Ea5ydfQulcLLY00zCD3Hk jI4DjiOCnLozeAnUNbpKZX1aHtNyHAiuI2P4dpMt2JHDo7YVcxi3hl09OuUJL1KRxxus exHg== X-Gm-Message-State: AOAM530nVGuFePMuar/D4qO/Jve7k6zYu7elbOTBOcqQbzosbrl2iwgZ 1Smt0f1aKbv2ke/9XkJ0yRA4wPds+kCOMMzZ94UpOJuv X-Google-Smtp-Source: ABdhPJxRFtyJp1tZ+HioE3vlOFvVHCWtnaJxYQgCxv1aKGweVa32E2fq+27a96LfqGIyz99oBQxT8XIFACN97foEs8I= X-Received: by 2002:a17:906:b296:: with SMTP id q22mr6182541ejz.161.1617831667800; Wed, 07 Apr 2021 14:41:07 -0700 (PDT) MIME-Version: 1.0 References: <20210407030548.189104-1-yanfei.xu@windriver.com> <20210407030548.189104-3-yanfei.xu@windriver.com> In-Reply-To: <20210407030548.189104-3-yanfei.xu@windriver.com> From: Yang Shi Date: Wed, 7 Apr 2021 14:40:56 -0700 Message-ID: Subject: Re: [PATCH v2 2/2] mm: khugepaged: check MMF_DISABLE_THP ahead of iterating over vmas To: "Xu, Yanfei" Cc: Linux MM , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: B5EA9E000102 X-Stat-Signature: 8ywtkmw84iotk8qp1y43u7mt14m8oho6 Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf13; identity=mailfrom; envelope-from=""; helo=mail-ej1-f46.google.com; client-ip=209.85.218.46 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617831666-971524 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: On Tue, Apr 6, 2021 at 8:06 PM wrote: > > From: Yanfei Xu > > We could check MMF_DISABLE_THP ahead of iterating over all of vma. > Otherwise if some mm_struct contain a large number of vma, there will > be amounts meaningless cpu cycles cost. Reviewed-by: Yang Shi > > Signed-off-by: Yanfei Xu > --- > mm/khugepaged.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index a6012b9259a2..f4ad25a7db55 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -2094,6 +2094,8 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, > */ > if (unlikely(!mmap_read_trylock(mm))) > goto breakouterloop_mmap_lock; > + if (test_bit(MMF_DISABLE_THP, &mm->flags)) > + goto breakouterloop; > if (likely(!khugepaged_test_exit(mm))) > vma = find_vma(mm, khugepaged_scan.address); > > -- > 2.27.0 >