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 A8362C3A5A2 for ; Fri, 20 Sep 2019 21:04:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7433B205F4 for ; Fri, 20 Sep 2019 21:04:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569013460; bh=VubYVjGnRP2aZyg2jw4IPrIbkXEgM+ozY9rWM9RJIW8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=qTlspw64I9dea0Lr4i37z3hM4MkmbZreEDPr9pMLz/mvkfNfefQrA8pu/AdEJmyej FiEHls8p7/iPwyQ2tca5H08qEWopZpVYdtCWB3BGftxJdSngaeLU6nV2ZQW3uIF8tB hG2FyuJODEYovFuD8Pwb3i4tquDsre9vdq1HDwAQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388000AbfITVET (ORCPT ); Fri, 20 Sep 2019 17:04:19 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:41811 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387479AbfITVET (ORCPT ); Fri, 20 Sep 2019 17:04:19 -0400 Received: by mail-qt1-f196.google.com with SMTP id x4so10249212qtq.8 for ; Fri, 20 Sep 2019 14:04:17 -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=MclSGY+9kJ6oxOJZqAtmvR1JbCyv4F0ekRMFCKZI+a4=; b=W1TT8PeUF03mOyewPJFuLQBqka1UfjINtniTRkofWjYTeZr931izfgfsaaIaGErNvN s+tqTvczyGothiXkzQAVqv6bMD+v5POW9PRTP9MCT4B4+kbgaqttHEnYCkIJpNr8KyZq J00Yft/zFKYRSbnWXIvIGWuDb8cJkXWFt0ZzMflOGQncVr+QH+AqAwiw6NLyX7QVJTQV Gw0ozqgf9/xrI2HCmHhrDE2KIKoets0i+olYMsFxjNPWAfBdkswwXqWtVzs6VBjDhxrM F0LZxLpe+peE9RgPikO1I/l0tH87JsT1rZ6wAWb6FjI0RANiw5o6QyWhAVw8F8kujYjZ yWOA== 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=MclSGY+9kJ6oxOJZqAtmvR1JbCyv4F0ekRMFCKZI+a4=; b=RRQwkPHQ7ISJFO7Wd3dW5oOje89xdFGOBnjubQKLS2Wn1FsOvznS8Gz2Yp+E9NOL2m LE2Rki0JKVUYoxht9JKUh0eHJm1DgXOzJYPaqfwUDiBMDn9yhGgVbqfrszq+AyhIRRny khPMDP86tpTDzQLnhXqJtIBX7yUhx46Jg7PAcKPMx5EdslpCR1x0rEacSA6ppSGXrjkj w+tw7qrSNDVfH67SZcqhs/zdNexeAiX1+coGV6Rub97bXAFulLeugcoPTAu1jfcWYImB 9xow4rAeoh6BESPDKiK9gQ7d1S7ZPE5dQ2C/xXmIiOXtMiIIHq3MpCQFzlpla8OwzZf4 Ikhg== X-Gm-Message-State: APjAAAXQYGEuvqjmnxd2urlz9HOTdiUp9f2ImZQmJWFz4lSO09o3MC65 xE3tIh1y/LTKzYsRs/52Tlg= X-Google-Smtp-Source: APXvYqzaXZKtBOUh/fvkW1VV/1BXJ0Ju9+8M/LnxzHTwlxNpqt4wp9bha/+1b4vMaHhbWO5TZz5eRg== X-Received: by 2002:a0c:82a2:: with SMTP id i31mr14464002qva.160.1569013456404; Fri, 20 Sep 2019 14:04:16 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::7520]) by smtp.gmail.com with ESMTPSA id a72sm1367119qkg.77.2019.09.20.14.04.13 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 20 Sep 2019 14:04:14 -0700 (PDT) Date: Fri, 20 Sep 2019 14:04:11 -0700 From: Tejun Heo To: Namhyung Kim Cc: Song Liu , Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , LKML , Jiri Olsa , Alexander Shishkin , Stephane Eranian , Li Zefan , Johannes Weiner Subject: Re: [PATCH 2/9] perf/core: Add PERF_SAMPLE_CGROUP feature Message-ID: <20190920210411.GB2233839@devbig004.ftw2.facebook.com> References: <20190828073130.83800-1-namhyung@kernel.org> <20190828073130.83800-3-namhyung@kernel.org> <20190828144911.GR2263813@devbig004.ftw2.facebook.com> <20190831030321.GA93532@google.com> <20190831045815.GE2263813@devbig004.ftw2.facebook.com> <20190916152325.GD3084169@devbig004.ftw2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 On Fri, Sep 20, 2019 at 05:47:45PM +0900, Namhyung Kim wrote: > Thanks for the sharing information! For 32-bit, while the ino itself is not > monotonic, gen << 32 + ino is monotonic right? I think we can use the It's not. gen gets incremented on every allocation, so it has not high but still realistic chance of collisions. Thanks. -- tejun