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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86C92C4332F for ; Mon, 25 Oct 2021 18:10:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2CFA260F4F for ; Mon, 25 Oct 2021 18:10:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2CFA260F4F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 61E50940008; Mon, 25 Oct 2021 14:10:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5CD83940007; Mon, 25 Oct 2021 14:10:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 46F54940008; Mon, 25 Oct 2021 14:10:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0085.hostedemail.com [216.40.44.85]) by kanga.kvack.org (Postfix) with ESMTP id 34C14940007 for ; Mon, 25 Oct 2021 14:10:22 -0400 (EDT) Received: from smtpin33.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id DE036183432D2 for ; Mon, 25 Oct 2021 18:10:21 +0000 (UTC) X-FDA: 78735749442.33.A64AF58 Received: from mail-pg1-f175.google.com (mail-pg1-f175.google.com [209.85.215.175]) by imf02.hostedemail.com (Postfix) with ESMTP id 449617001A08 for ; Mon, 25 Oct 2021 18:10:18 +0000 (UTC) Received: by mail-pg1-f175.google.com with SMTP id q187so11765564pgq.2 for ; Mon, 25 Oct 2021 11:10:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+d0Qbu1iomeuu1b0XB1a5sl30MKuGON4H+QXA4yUgY8=; b=WCK5zsT3weZzmYfIBAoy+kmVYDC0BYJ6lommblY/oHQV/xnwun3Uuo6iPEc6fribAy uKfJmIaAC8d2IH9Fa1mmRfoYRrwRwP1b1mR941fuqAckUxtMloqQ/4udOb2NtHd52T4x btUqWEi40v7aAJ/kn0eITbpogV53PIPoZkWn5/fHVTFIfHYplnOkqXwvA6l4R+9yB/kA ZCzwpDyVG2JvfWhgzh+GsPs4pXSG5nwwiXWwa5IeI0FTbNTdvvfoNGPkZusYqQAVJ3VF seJzxEu8gZIw4wV8yg4cJdTvrUfUi0Edyo4hqlpILDOBWjDUk12ctSH48FWpUaDBvut0 TZHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+d0Qbu1iomeuu1b0XB1a5sl30MKuGON4H+QXA4yUgY8=; b=RiqM/dZrpoLKhfF+q8BF5MuQjBl2V0alNlN+8XT8JwAec9ySCZNYBAu7Xt6HZ0tq4/ cy3j/X02DHBdcORQM5vYwfnwoZItTURBXo1Dg3tILXZm7Q9AjqkBs53jKMeYHGkQxrk9 QTX8Dsaac2CXJc3Kl4ZZNRdOln+s3gy4TE1CQU0Z5Cs2NXhJdgYEYDUtYCYjPUOdlJWv RzQiaHFnbqssLTRuLBndn7SH906MslLmLUkI6h6BP4AQRZ4du/YGkkCeKF6eui7sPSM3 XbhkRM0Czi9H1M92WSbAsg5CH1W57y9CN8LR3pRVQythtUSiMrC8u5ahVbzYT6DMhjpn v8kQ== X-Gm-Message-State: AOAM532UDELj9D2y6qaMpBAxEmmiGZLNaa0ZokYYDLzWM6lXDnbnGUfw 8uZdcYU4/uaAIyICy6ByYMikaSDrLKeUdDDGTNU= X-Google-Smtp-Source: ABdhPJzwioKhEvGpI9odjpTyYQzGvhTJexObl6tmfLM4u6lVqCdB58boI2emDBXKBO3+eM8Bu2Wsfnb0z1J4L4F8xhg= X-Received: by 2002:a65:4008:: with SMTP id f8mr14907559pgp.310.1635185420342; Mon, 25 Oct 2021 11:10:20 -0700 (PDT) MIME-Version: 1.0 References: <20211025083315.4752-1-laoar.shao@gmail.com> In-Reply-To: <20211025083315.4752-1-laoar.shao@gmail.com> From: Alexei Starovoitov Date: Mon, 25 Oct 2021 11:10:09 -0700 Message-ID: Subject: Re: [PATCH v6 00/12] extend task comm from 16 to 24 To: Yafang Shao Cc: Andrew Morton , Kees Cook , Steven Rostedt , Mathieu Desnoyers , Arnaldo Carvalho de Melo , Petr Mladek , Peter Zijlstra , Alexander Viro , Valentin Schneider , "Zhang, Qiang" , robdclark@chromium.org, Christian Brauner , Dietmar Eggemann , Ingo Molnar , Juri Lelli , Vincent Guittot , "David S. Miller" , Jakub Kicinski , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , dennis.dalessandro@cornelisnetworks.com, mike.marciniszyn@cornelisnetworks.com, Doug Ledford , Jason Gunthorpe , linux-rdma@vger.kernel.org, Network Development , bpf , linux-perf-users@vger.kernel.org, Linux-Fsdevel , linux-mm , LKML , kernel test robot , kbuild test robot Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 449617001A08 X-Stat-Signature: jju7gqyxjhfruumypxpu3z886x3q6ue1 Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=WCK5zsT3; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf02.hostedemail.com: domain of alexei.starovoitov@gmail.com designates 209.85.215.175 as permitted sender) smtp.mailfrom=alexei.starovoitov@gmail.com X-HE-Tag: 1635185418-963685 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 Mon, Oct 25, 2021 at 1:33 AM Yafang Shao wrote: > > There're many truncated kthreads in the kernel, which may make trouble > for the user, for example, the user can't get detailed device > information from the task comm. > > This patchset tries to improve this problem fundamentally by extending > the task comm size from 16 to 24. In order to do that, we have to do > some cleanups first. It looks like a churn that doesn't really address the problem. If we were to allow long names then make it into a pointer and use 16 byte as an optimized storage for short names. Any longer name would be a pointer. In other words make it similar to dentry->d_iname.