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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 5F134C433DB for ; Thu, 28 Jan 2021 13:50:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D53F46146D for ; Thu, 28 Jan 2021 13:50:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D53F46146D 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 469936B0074; Thu, 28 Jan 2021 08:50:38 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3F3456B0075; Thu, 28 Jan 2021 08:50:38 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2BA806B0078; Thu, 28 Jan 2021 08:50:38 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0236.hostedemail.com [216.40.44.236]) by kanga.kvack.org (Postfix) with ESMTP id 12EAD6B0074 for ; Thu, 28 Jan 2021 08:50:38 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id D40B01EF3 for ; Thu, 28 Jan 2021 13:50:37 +0000 (UTC) X-FDA: 77755318914.20.birth78_1612fdd275a0 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 946F4180C07AB for ; Thu, 28 Jan 2021 13:50:37 +0000 (UTC) X-HE-Tag: birth78_1612fdd275a0 X-Filterd-Recvd-Size: 3121 Received: from mail-lf1-f49.google.com (mail-lf1-f49.google.com [209.85.167.49]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Thu, 28 Jan 2021 13:50:37 +0000 (UTC) Received: by mail-lf1-f49.google.com with SMTP id e2so4027960lfj.13 for ; Thu, 28 Jan 2021 05:50:36 -0800 (PST) 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=tklYkH91Jo65DvjESMcQp5Na5zQGHnu4lkAZqSyesDo=; b=HTphw51anwmBq/CktrM0CQAvI7gtylgyF0MAijUtw7mOBWBtyqBUh9D/i7oNv/W8r2 4wpU7fNYecfLhNrNRMlBnfEgb1/dJfNdt8Jm/3nBcv3I+270Dk8U7QkSpprweq7VVejX G7nw2YQon3qNK+IL/kFJ2vmDgOdU4Fi6sBgyg6UXeGMVfPgxh4c4KdrCqw04YUHCXW9I 9/MdFflfxSWA+yK8CUfAgJeIBGC7SxphY9FNlXX5przydKENIH8OHhjSYdf9GoVtbyyC 9b6c6J4YUkKvkMMtWaPA/WP0fBsQGkljeedwrQ3rxyb5qdgqne4QAEjOpbXkQremjUEU sg5A== 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=tklYkH91Jo65DvjESMcQp5Na5zQGHnu4lkAZqSyesDo=; b=uVxHPXXzkin/ei743IbN+pJvutoh19vUHISxQ5JcxFGHMU5QCJbEriCCppbms4JNoJ JzQMni1+Se6f5beBEuIPOahNVR/G2yoCWj395O7WL6nvi27BpiZ5ajFxGQNg08hwYwG6 cXP1OncnlG1j0FOQcfOA5KK9aa1CbsPK4t0gFYSGT3df+JRwXTdZl1Eb5fyW4hHEVKRh qAgEXuFVKsKw5d+ZYCtWMfCd3HNdC3df1Uk3b0WrWgXOwlL4ngcKh94Fx0iShProRg9b ZaNN38cqBg1h2p56C/9JYTeGOswh60RoJsdHSK/ghnnYdL8Z1FcXc78/wI6m0zCckFcJ GPQQ== X-Gm-Message-State: AOAM533pdxd5XbhFnqASF9WRm+gjse6pOQ2b94gaXM62tPHS+kDyy7X9 pzKihmMpKvhtVuJmkg2adhxrio+ieGDmXXVvIn8= X-Google-Smtp-Source: ABdhPJz5XZuiFSYzlyVs+XFmOg3OdZ9lMQg9DRggO/+ZVqnMy7Juxjxv86IaYOTWyFnxFvpULz/Pt/M8OnFbVspZQN8= X-Received: by 2002:a19:240a:: with SMTP id k10mr7871419lfk.442.1611841835599; Thu, 28 Jan 2021 05:50:35 -0800 (PST) MIME-Version: 1.0 References: <20210128130411.6125-1-vvghjk1234@gmail.com> <20210128132508.GE3592@techsingularity.net> In-Reply-To: <20210128132508.GE3592@techsingularity.net> From: Wonhyuk Yang Date: Thu, 28 Jan 2021 22:50:24 +0900 Message-ID: Subject: Re: [PATCH v2] mm/compactoin: Fix misbehaviors of fast_find_migrateblock() To: Mel Gorman Cc: Andrew Morton , Vlastimil Babka , linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" 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 Thu, Jan 28, 2021 at 10:25 PM Mel Gorman wrote: > > As nr_scanned is post-incremented, this will still consider if the page > should be used when the limit is reached. ++nr_scanned? Hi, Let's consider that limit is 4, nr_scanned is 0 and loop until reach the limit. 1) pre-increment: it will search three times.(0,1,2) 2) post-increment: it will search four times. (0,1,2,3) So you mean that searching three times is correct?