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=-11.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 36182C433E1 for ; Mon, 22 Jun 2020 17:13:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1148E20707 for ; Mon, 22 Jun 2020 17:13:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="aEK0cKVi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729876AbgFVRNA (ORCPT ); Mon, 22 Jun 2020 13:13:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729782AbgFVRNA (ORCPT ); Mon, 22 Jun 2020 13:13:00 -0400 Received: from mail-lj1-x242.google.com (mail-lj1-x242.google.com [IPv6:2a00:1450:4864:20::242]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99BF3C061573 for ; Mon, 22 Jun 2020 10:12:59 -0700 (PDT) Received: by mail-lj1-x242.google.com with SMTP id e4so20213187ljn.4 for ; Mon, 22 Jun 2020 10:12:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MczyUKnr4KWUAWPoNy99bqHhQdcxqPt73wnuGURBYbQ=; b=aEK0cKViZ7S0ph9kpZzVfQ8A5ynsiYQa5Ts9xIn8wvCwAjTrINbnY8Byk4x5iPjnzi 0f5U3r+rzHHR+UgvV3vizeA9X+il3u/h+WckB5KVVg0HTFJ6hBT6RQIzbULIczNgw2TG JPGAvh8TP5j0jkbZJhlJ0T1X0+O0QjBCuUNiETb0lo5MRGcIb055JksnVkM2kUmooeqj /3k8TZrUdya8ulEA7Gqc2fiZZ0wyB+IpsmEqOz9/k/qrTX1zaqyhc2QbdlmOipvZ4YQ8 l/8kfFRLCxb4SoYGvY9E4D9vtmEloxBLuTQJ+Xfn+eMPqykXBHVK/GEU95kaavsusBqI ia0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MczyUKnr4KWUAWPoNy99bqHhQdcxqPt73wnuGURBYbQ=; b=fZnUOMdZEHrEXBt5CjzaDj4WXCcMZqWcZhGNJJo4+b2Ky/T0GYNRWAVAWhvRASLKmU wuqLS7vhvLd6Ze6GbexFOlGNTWgTcJA5kL78UK42TeZm24TmdnMbtdb762SA9pdIyPY9 Kc4IEkOiOBRh9stSfWP6hHg/kWA+bOBrk4RkyB9OfbZsKPGnl/MLuAS2g2WsP9hxeLat M9g3KAtaxwqqfT+u1w4dTOzb0MfsbDEVnW34LJ+JbEY0f2bMsemt9ttojv0VXj+Lknmz sQXvSA3xjBO0sLtsg7KeCnUSyx+e4xs42d/xovK1ymyUQviGWgaDX3geqcGMGrnTcFEs /qOA== X-Gm-Message-State: AOAM532LG+H6tek1pDLiVexYpTMTpBxQ4uefp5r/17+FpiKt6iO9lU/k EbW8plcPV63ylGDfD973aZStw2Xtea1IyLNE/KX+rw== X-Google-Smtp-Source: ABdhPJzz/cwMqUCaSL9gP+/s5pE/WjebWsM0Egj2WRCtgz8ZOXxoB5kYkg/zYWM8ANzketpHei1+R4XnkESbxhA0b3g= X-Received: by 2002:a2e:910c:: with SMTP id m12mr9512410ljg.332.1592845977819; Mon, 22 Jun 2020 10:12:57 -0700 (PDT) MIME-Version: 1.0 References: <20200608230654.828134-1-guro@fb.com> <20200608230654.828134-11-guro@fb.com> In-Reply-To: <20200608230654.828134-11-guro@fb.com> From: Shakeel Butt Date: Mon, 22 Jun 2020 10:12:46 -0700 Message-ID: Subject: Re: [PATCH v6 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo To: Roman Gushchin Cc: Andrew Morton , Christoph Lameter , Johannes Weiner , Michal Hocko , Linux MM , Vlastimil Babka , Kernel Team , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 8, 2020 at 4:07 PM Roman Gushchin wrote: > > Deprecate memory.kmem.slabinfo. > > An empty file will be presented if corresponding config options are > enabled. > > The interface is implementation dependent, isn't present in cgroup v2, > and is generally useful only for core mm debugging purposes. In other > words, it doesn't provide any value for the absolute majority of users. > > A drgn-based replacement can be found in tools/cgroup/slabinfo.py . > It does support cgroup v1 and v2, mimics memory.kmem.slabinfo output > and also allows to get any additional information without a need > to recompile the kernel. > > If a drgn-based solution is too slow for a task, a bpf-based tracing > tool can be used, which can easily keep track of all slab allocations > belonging to a memory cgroup. > > Signed-off-by: Roman Gushchin > Acked-by: Johannes Weiner > Reviewed-by: Vlastimil Babka Hi Roman, I am not against removing the memory.kmem.slabinfo interface but I would like to have an alternative solution more accessible than tools/cgroup/slabinfo.py. In our case, we don't have ssh access and if we need something for debugging, it is much more preferable to provide a file to read to SREs. After the review, that file will be added to a whitelist and then we can directly read that file through automated tools without approval for each request. I am just wondering if a file interface can be provided for whatever tools/cgroup/slabinfo.py is providing. Shakeel