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=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 4DEA0C433E5 for ; Mon, 27 Jul 2020 17:29:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F1D020729 for ; Mon, 27 Jul 2020 17:29:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bmEegtJg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730994AbgG0R3T (ORCPT ); Mon, 27 Jul 2020 13:29:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730974AbgG0R3S (ORCPT ); Mon, 27 Jul 2020 13:29:18 -0400 Received: from mail-io1-xd44.google.com (mail-io1-xd44.google.com [IPv6:2607:f8b0:4864:20::d44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 564E8C061794; Mon, 27 Jul 2020 10:29:18 -0700 (PDT) Received: by mail-io1-xd44.google.com with SMTP id q75so9663868iod.1; Mon, 27 Jul 2020 10:29:18 -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=Twl8egs2sgu9K2jUzyioOJdzChfT8oqMYRNtXj1w94Y=; b=bmEegtJgjmIbLBbTat5MprW8AbcHi/GCR+b/be88P4z6uYRhqOPQwZvY+KgtlwvHg1 N4ICNnkrSuvMfHyrhCaMPTSaCWpTNZiYMoaBCFSEiX6+67oaI2o2Df46D+cTiuk6RKdH LWIB01sC9tVfimdUuCkacMamqOI4goVj7R8ybw+7+k22pVMpYzsI0LGnufsKU5FycBKV 2q73J0Qm7SMd32tsPQMf3QShXIO6yNCb3aa4W9pF7X/T24ON0LbQvPOAuKLjAIkIiUYx ZyhLhQaLzj6rP7kU8egE6STMuJZQjb41Nkl75U7o8ci1ybC3TTzICtF1T3ozEhlXjbbt MncQ== 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=Twl8egs2sgu9K2jUzyioOJdzChfT8oqMYRNtXj1w94Y=; b=ZOw7tQ9WlQgOqCxf8shf5TkZpdYXX64wYNNxhoqzAoYYDGZ/cLoIO3AVEcLuh30R1d jPycdmeMRCbG7HQlpAduZVQ7JP6yZNZTgf/ZGRtsQao7vyHX4Y8FSTo7GIHNaXhsrKNc l+dfH0HQMV+SdyrfF15uqoluQo334U6DmqfQsCbkpG7dUG6RjOBO+8Yf8JqjP75osOzL vS9VJqzf1RpU5tfz/xsZMbZ4eiM6+Msu6uHB2c3w+QfDUK2UEKC5Xg2ajXDVTxqK4Czy WwDKrHa+dt3XXM7BYmUtOE/+sHJr3R/eUWoiBdvQVhvmTPT+X4djf6LSM+g0Y3v2cAb9 Uzag== X-Gm-Message-State: AOAM531alpy9GJrHWqLYCV9eF5VWd+MtDjdG6OD8KTitVzXCHP8nHRuz 3IiOdlTUclxoZ5A0XySB8TSXRv3a/Pzn7gsuLuc= X-Google-Smtp-Source: ABdhPJxxgfdHHeyfu9fL+ZOZXfFlu0kc7hS7ebEk7MvDy1g28AJrX540XgnyyU+MlbYM5jUv6exPXnqOeN3OwC8/9tI= X-Received: by 2002:a5d:9051:: with SMTP id v17mr6151014ioq.88.1595870957629; Mon, 27 Jul 2020 10:29:17 -0700 (PDT) MIME-Version: 1.0 References: <1595681998-19193-1-git-send-email-alex.shi@linux.alibaba.com> <1595681998-19193-4-git-send-email-alex.shi@linux.alibaba.com> In-Reply-To: <1595681998-19193-4-git-send-email-alex.shi@linux.alibaba.com> From: Alexander Duyck Date: Mon, 27 Jul 2020 10:29:06 -0700 Message-ID: Subject: Re: [PATCH v17 03/21] mm/compaction: correct the comments of compact_defer_shift To: Alex Shi Cc: Andrew Morton , Mel Gorman , Tejun Heo , Hugh Dickins , Konstantin Khlebnikov , Daniel Jordan , Yang Shi , Matthew Wilcox , Johannes Weiner , kbuild test robot , linux-mm , LKML , cgroups@vger.kernel.org, Shakeel Butt , Joonsoo Kim , Wei Yang , "Kirill A. Shutemov" , Rong Chen Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 25, 2020 at 6:00 AM Alex Shi wrote: > > There is no compact_defer_limit. It should be compact_defer_shift in > use. and add compact_order_failed explanation. > > Signed-off-by: Alex Shi > Cc: Andrew Morton > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > --- > include/linux/mmzone.h | 1 + > mm/compaction.c | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index f6f884970511..14c668b7e793 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -512,6 +512,7 @@ struct zone { > * On compaction failure, 1< * are skipped before trying again. The number attempted since > * last failure is tracked with compact_considered. > + * compact_order_failed is the minimum compaction failed order. > */ > unsigned int compact_considered; > unsigned int compact_defer_shift; > diff --git a/mm/compaction.c b/mm/compaction.c > index 86375605faa9..cd1ef9e5e638 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -136,7 +136,7 @@ void __ClearPageMovable(struct page *page) > > /* > * Compaction is deferred when compaction fails to result in a page > - * allocation success. 1 << compact_defer_limit compactions are skipped up > + * allocation success. compact_defer_shift++, compactions are skipped up > * to a limit of 1 << COMPACT_MAX_DEFER_SHIFT > */ > void defer_compaction(struct zone *zone, int order) So this doesn't read right. I wouldn't keep the "++," in the explanation, and if we are going to refer to a limit of "1 << COMPACT_MAX_DEFER_SHIFT" then maybe this should be left as "1 << compact_defer_shift".