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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 D6CCDC3A5A1 for ; Wed, 28 Aug 2019 14:48:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A83202077B for ; Wed, 28 Aug 2019 14:48:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567003719; bh=DrggFc35vDJ5BKYSOvDqyafOdM1VWe8R/POFM1RO03k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=veJP+pCM0G+pnT7kkpVt6aKsmfuLvt/4C+dhZkzJVyjYkIr223rTfwlVJrbEp/ypL 5mLV4spHVa+BrC/nViHyCW0be/vDe7llfGJa58CEAXh7qYHvVXd2dT9NF649qlTxhG 0c2sK9XvTiw7urWbN/rqtAnjXL3wLyUS3uYnYmOw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726764AbfH1Osi (ORCPT ); Wed, 28 Aug 2019 10:48:38 -0400 Received: from mail-qk1-f196.google.com ([209.85.222.196]:39300 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726272AbfH1Osi (ORCPT ); Wed, 28 Aug 2019 10:48:38 -0400 Received: by mail-qk1-f196.google.com with SMTP id 4so2611675qki.6 for ; Wed, 28 Aug 2019 07:48:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=p11EOwu/uVWWwafbZoZanI/o5iGdReqlGXH8aeEIwZs=; b=qRCmLgBMPolI5D1ew8nG90rOtC7mFtSfXX2Jrds5xSvZmTrMg/CHVyjmHKQwjOQ1Yl IFz51blzXZUBrSOQX5/zWXzKDY4iihZvRE0aVY71k8y66pk3jz9EHnjaHjF2DOUAE2b/ m1tXhsQbenmBNS4WG/OtjRkbC15NJF/rPh5TC4Dgm+7ghafp+i8NJVZ/MtSQk7RHptg3 u/uNWe2nSOVte8P2CiC8je410mnaUQzTd3mlgGES1SdkfRO+g5QLpqGXeTcD/kv02glK uhMzGCpNDwIS07fcqh79UmUAjOdk9RosI22JvLaCt6VZsiXr1boDM2s3R2qnbYE1PXYa Ra3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=p11EOwu/uVWWwafbZoZanI/o5iGdReqlGXH8aeEIwZs=; b=CH801lXULXnoR5PzdLay4B8Gdc8cvJV/0m1YIjSlRh+RetWObpPIBjh4yMwCRTj02d Z3AcuD3QV2kJE/H9gbY/N/9HLWOM9vQaD0GY1o3UGkTvHIOYzJPkFjMwE8EMJqA9myrn ZC1ILdkyYtppbP39sRSiIZh0EsAEpfXg7m8+JpzSlCRmZ2dY88EYfKcsjjLpWIeH+HX2 SMderAu0ydErXMducjodNcDCWVS8Ya9ZcWv8SzH5pjCCeByNmVP7i1aWgNHkA162sT1N SA8g+Jo8ulsexw5VqLevm59bgi+jqQ2OySZ5+vstTh7xbIGLvSaMqo0oCR2x05ARwQ7m W9eQ== X-Gm-Message-State: APjAAAW6zztZXGJbEgczgRrmK+fdSmiVEl5ANJdV/8zOito1sTgYJGXX 9GImKUM59080p/h9Rfi91T8= X-Google-Smtp-Source: APXvYqyI/lM8w93rKPohI6SnUh1EbEp6HqeyFc9b6D2tyMIFivGgf81C5M52iseVgilUGgu7Q6ZOuQ== X-Received: by 2002:a37:813:: with SMTP id 19mr3865720qki.427.1567003713733; Wed, 28 Aug 2019 07:48:33 -0700 (PDT) Received: from localhost ([2620:10d:c091:500::1:c231]) by smtp.gmail.com with ESMTPSA id h1sm1588941qtc.92.2019.08.28.07.48.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 28 Aug 2019 07:48:33 -0700 (PDT) Date: Wed, 28 Aug 2019 07:48:30 -0700 From: Tejun Heo To: Namhyung Kim Cc: Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , LKML , Jiri Olsa , Alexander Shishkin , Stephane Eranian , Li Zefan , Johannes Weiner , Adrian Hunter Subject: Re: [PATCH 1/9] perf/core: Add PERF_RECORD_CGROUP event Message-ID: <20190828144830.GQ2263813@devbig004.ftw2.facebook.com> References: <20190828073130.83800-1-namhyung@kernel.org> <20190828073130.83800-2-namhyung@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190828073130.83800-2-namhyung@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Namhyung. On Wed, Aug 28, 2019 at 04:31:22PM +0900, Namhyung Kim wrote: > + * struct { > + * struct perf_event_header header; > + * u64 ino; > + * u64 path_len; > + * char path[]; ino and path aren't great identifers for cgroups because both can get recycled pretty quickly. Can you please take a look at KERNFS_ROOT_SUPPORT_EXPORTOP? That's the fhandle that cgroup uses, currently the standard ino+gen which isn't ideal but good enough. Another benefit is that the path can also be resolved efficiently from userspace given the handle. Thanks. -- tejun