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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4AC1C77B75 for ; Wed, 3 May 2023 17:52:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229996AbjECRwh (ORCPT ); Wed, 3 May 2023 13:52:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229539AbjECRwa (ORCPT ); Wed, 3 May 2023 13:52:30 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE4B57A93 for ; Wed, 3 May 2023 10:52:28 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-55a9614c154so41222797b3.2 for ; Wed, 03 May 2023 10:52:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683136348; x=1685728348; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=RZYSjSUR1TVNLCONU/ktPYm4b5B8g2ry+YtlqDqVDwA=; b=06jHQvfsD3SDUJMSu6ULA+Lqi2Rheb3urP5pez8MV1dafSxYy0/iecp7i3W9YM8kw0 Z8sDp7LJx6LxY6887Lp9tpfA2PRnZ+5qsmf/2ne9kOhMV6oNSgGhzuXqwMC3i6HQpw8p D8X9p8yhzKfJ/bgSYEC5uIPGefibu0HxTKSIOIWINb3PnNySA5vrkGDdfiFHPxJVa3eg fzeTNSZPX/rk1YdIOuq6L93DdQc6YUPO6bt/7O5Wu9R3mWPc7MGSncLmqdQi7vfNKPNv eNUJWumFkZPqhtINkPq+WqdkN0g7gmfclLzeSV9JpuQEB/g+6NsZV9V3lB08IqjbYy4P Yf/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683136348; x=1685728348; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=RZYSjSUR1TVNLCONU/ktPYm4b5B8g2ry+YtlqDqVDwA=; b=MxcEocSlPbaTFSzraQfaMWqAfguK792/4Hd7atEs4wrz/kg5DjlbMwaJQpGCA4EGvo XUUWlgoJcj7AWpgv5OUHQjEkBxq6cUfhuSeh/A+9xkClCOFT+kTlxuxqtKMADnwFwzGc 1msMQ23/+frGip3F59jOffb9zxkZlTqRtNjHvebmricZ1mvGmsCc3PsAaClh7Zwt895a sh/yNjCuRWM/Aii6jRCu4hE2wXmBtOdw20ygso+y/+eo4jpBj2ruvp6Lnd9+VBdwbUV1 8TQ7mamTqOjI9rISNrP9HEEn9AJTUx+5tV5AKOedPHGlWbrgDTOlvEScH/PdsFLrRe1Y AI/g== X-Gm-Message-State: AC+VfDz6x2tTCiGwHvRBGe+W17MA+B8k4AHSmbyExC3JmmxrGvgShARV /QlJHMRRJGVWD/4Fy9u2PfH/8PhA3KJ/wA== X-Google-Smtp-Source: ACHHUZ59iAxehhHtXCF+bq4Cz843yfeiUKwoHIntE4kQjpxt94wcmUOFlOiSBWPXCkx4jhERPUtGCVXYZdfeOw== X-Received: from shakeelb.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:262e]) (user=shakeelb job=sendgmr) by 2002:a81:4054:0:b0:534:d71f:14e6 with SMTP id m20-20020a814054000000b00534d71f14e6mr12118393ywn.9.1683136347929; Wed, 03 May 2023 10:52:27 -0700 (PDT) Date: Wed, 3 May 2023 17:52:26 +0000 In-Reply-To: <20230428132406.2540811-2-yosryahmed@google.com> Mime-Version: 1.0 References: <20230428132406.2540811-1-yosryahmed@google.com> <20230428132406.2540811-2-yosryahmed@google.com> Message-ID: <20230503175226.nyjmmbnohm6xxckd@google.com> Subject: Re: [PATCH v2 1/2] memcg: use seq_buf_do_printk() with mem_cgroup_print_oom_meminfo() From: Shakeel Butt To: Yosry Ahmed Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Andrew Morton , Muchun Song , Sergey Senozhatsky , Steven Rostedt , Petr Mladek , Chris Li , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 28, 2023 at 01:24:05PM +0000, Yosry Ahmed wrote: > Currently, we format all the memcg stats into a buffer in > mem_cgroup_print_oom_meminfo() and use pr_info() to dump it to the logs. > However, this buffer is large in size. Although it is currently working > as intended, ther is a dependency between the memcg stats buffer and the > printk record size limit. > > If we add more stats in the future and the buffer becomes larger than > the printk record size limit, or if the prink record size limit is > reduced, the logs may be truncated. > > It is safer to use seq_buf_do_printk(), which will automatically break > up the buffer at line breaks and issue small printk() calls. > > Refactor the code to move the seq_buf from memory_stat_format() to its > callers, and use seq_buf_do_printk() to print the seq_buf in > mem_cgroup_print_oom_meminfo(). > > Signed-off-by: Yosry Ahmed > Acked-by: Michal Hocko > Reviewed-by: Sergey Senozhatsky Acked-by: Shakeel Butt