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 9E1C3C433B4 for ; Wed, 7 Apr 2021 21:41:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C57861165 for ; Wed, 7 Apr 2021 21:41:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233976AbhDGVlW (ORCPT ); Wed, 7 Apr 2021 17:41:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233880AbhDGVlU (ORCPT ); Wed, 7 Apr 2021 17:41:20 -0400 Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45F47C061761 for ; Wed, 7 Apr 2021 14:41:09 -0700 (PDT) Received: by mail-ej1-x62e.google.com with SMTP id u17so23812706ejk.2 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=cVZ5AbLCtKtfilRB0J+qt9x37LmzLEQXwuppDaaLGyGc43Mk3YnQy/Dw0OTJ2QPeGC pQaiCbe6vP6WH7xC4YPAE014S3DCcSPNjyGNdeJaBGAFOzVQYX68u3P1CEn8VY8YOt9u /EjI1GpLysAc2Y+NuUJwDRDuSWfmRAeBdJVV+PGElsU6hBpa3ISu52BpsJaFRN6ZpiyS wsXEdFHsw2sUp6GwoTZwm94wnUgZlHC8miQh7xddUt4bLgGzqI9ic8tE8WtUxlLRZo1i hv1iF490bcizhepYMsGv6evY09KCH1gtraDcfoAxn0xKPhJFp6DL1lJ9I7E+cWYRHmHL BqnQ== X-Gm-Message-State: AOAM533CCThV3MAsUKk4nl4t6GvSBW9o2MR2qpu5lIHE5XBu4I5kACGe Ul4GwiBHYpSQo+vWDMUhVS2Fe/M8io7zleVUkac= 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" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 >