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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4913C433F5 for ; Tue, 23 Nov 2021 02:37:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E8AD46B0071; Mon, 22 Nov 2021 21:37:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E12A46B0072; Mon, 22 Nov 2021 21:37:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C8C0C6B0073; Mon, 22 Nov 2021 21:37:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0118.hostedemail.com [216.40.44.118]) by kanga.kvack.org (Postfix) with ESMTP id B48E36B0071 for ; Mon, 22 Nov 2021 21:37:39 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 7F10F89061 for ; Tue, 23 Nov 2021 02:37:29 +0000 (UTC) X-FDA: 78838633818.08.EEF1A20 Received: from mail-yb1-f174.google.com (mail-yb1-f174.google.com [209.85.219.174]) by imf11.hostedemail.com (Postfix) with ESMTP id 4CF0EF0000AC for ; Tue, 23 Nov 2021 02:37:28 +0000 (UTC) Received: by mail-yb1-f174.google.com with SMTP id v138so55381537ybb.8 for ; Mon, 22 Nov 2021 18:37:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=nTPvXtzHv6HZ++mcRaXSOv1XKXnEa9rG+SSlC7lYWhE=; b=bHQq0Hd9I+/x8g1ZiZ0Z02M8FM3ZseM/4YkRg0DgwRAubOxI1F66GBSSnLposQ8q4Y ZM0VPxfaLVAhZuZw4o9hBxpIt8KQSF3bp39N5GJlruPuG9tmzZGTUvjFK39kInRaraMF 7rwRsQKa4eu8zoZeZpq+NT+Wc6ZCWPxsHKnsf7Etw+JKv0aHa6BQ4gR3yjYGPvqRyD0r lsTm+CQQZ6wOPt5sNrS35Niz2aKBkxQ82ky0RbYVnCYKTNTMVM0rLM40UaLtTSNSxU1n VnqNWPUsrC9P9yN1kZh8AnqaIvybNdmzYY6Wm9B0BU9lYhN5bDHT5XVpKPD84TjCOUjU HrYA== 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:content-transfer-encoding; bh=nTPvXtzHv6HZ++mcRaXSOv1XKXnEa9rG+SSlC7lYWhE=; b=L0jdRxMKj55EWA23nsYJafobeZ3lre2Ps2qzLOn2zCarvWA6ZRNnbv/UemslXv07fV CDV7Pfr+bYdwxQuaQgoyk7oW/5eACFkZgvm++cWKgrBAfdwnbZII0sodNq5WY40KYxUq f9vEtSYEcX8V/33LMqwty2ghlB12M6ViEkYTX1OpYM3JLL4b/wdmFxegzOLBfUYdqXcL 1UqovzheosbOr3eGg6QGAa4RpCzv5hAtDQ/zYzZqXNwOrkG9ooglifKE2i3VfpLVi8IV wTCzwp1QXD4T3Y4PJA9hq0zdFbAyrjrf1V9j+Ptpqxauvc8JgEWJrRkwBm/vVBHDqaff b09g== X-Gm-Message-State: AOAM530iywG70lVUjP4ISwhvIfhkQnHdJqP5WJ5woKrnQZPg47EavSwM QYwJQ63XW3dxlaV/eZRGhAN/ubD09dqN7rPEm6bhoA== X-Google-Smtp-Source: ABdhPJyQuU6bla0tWR3Wxzlsd9NTbOuv/DnOYWhHE+zyUPIdWOhzHxoMxpfXFikXiLUYEMuzoAGwd/Vz1Gd5l2N773s= X-Received: by 2002:a05:6902:1144:: with SMTP id p4mr2434493ybu.404.1637635047527; Mon, 22 Nov 2021 18:37:27 -0800 (PST) MIME-Version: 1.0 References: <20211123001020.4083653-1-almasrymina@google.com> In-Reply-To: <20211123001020.4083653-1-almasrymina@google.com> From: Muchun Song Date: Tue, 23 Nov 2021 10:36:48 +0800 Message-ID: Subject: Re: [PATCH v8] hugetlb: Add hugetlb.*.numa_stat file To: Mina Almasry Cc: Tejun Heo , Zefan Li , Johannes Weiner , Jonathan Corbet , Mike Kravetz , Andrew Morton , Shuah Khan , Miaohe Lin , Oscar Salvador , Michal Hocko , David Rientjes , Shakeel Butt , Jue Wang , Yang Yao , Joanna Li , Cannon Matthews , Linux Memory Management List , LKML , Cgroups , linux-doc@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 4CF0EF0000AC X-Stat-Signature: ww31e4bha3oq77fqt9r6wiiq7hzqp1k8 Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b=bHQq0Hd9; dmarc=pass (policy=none) header.from=bytedance.com; spf=pass (imf11.hostedemail.com: domain of songmuchun@bytedance.com designates 209.85.219.174 as permitted sender) smtp.mailfrom=songmuchun@bytedance.com X-HE-Tag: 1637635048-942569 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 Tue, Nov 23, 2021 at 8:10 AM Mina Almasry wrote= : > > For hugetlb backed jobs/VMs it's critical to understand the numa > information for the memory backing these jobs to deliver optimal > performance. > > Currently this technically can be queried from /proc/self/numa_maps, but > there are significant issues with that. Namely: > 1. Memory can be mapped or unmapped. > 2. numa_maps are per process and need to be aggregated across all > processes in the cgroup. For shared memory this is more involved as > the userspace needs to make sure it doesn't double count shared > mappings. > 3. I believe querying numa_maps needs to hold the mmap_lock which adds > to the contention on this lock. > > For these reasons I propose simply adding hugetlb.*.numa_stat file, > which shows the numa information of the cgroup similarly to > memory.numa_stat. > > On cgroup-v2: > cat /sys/fs/cgroup/unified/test/hugetlb.2MB.numa_stat > total=3D2097152 N0=3D2097152 N1=3D0 > > On cgroup-v1: > cat /sys/fs/cgroup/hugetlb/test/hugetlb.2MB.numa_stat > total=3D2097152 N0=3D2097152 N1=3D0 > hierarichal_total=3D2097152 N0=3D2097152 N1=3D0 > > This patch was tested manually by allocating hugetlb memory and querying > the hugetlb.*.numa_stat file of the cgroup and its parents. > =EF=BF=BC > Cc: Mike Kravetz > Cc: Andrew Morton > Cc: Shuah Khan > Cc: Miaohe Lin > Cc: Oscar Salvador > Cc: Michal Hocko > Cc: Muchun Song > Cc: David Rientjes > Cc: Shakeel Butt > Cc: Jue Wang > Cc: Yang Yao > Cc: Joanna Li > Cc: Cannon Matthews > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > > Signed-off-by: Mina Almasry Reviewed-by: Muchun Song