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=-3.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 3777DC4724C for ; Thu, 7 May 2020 21:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0593220731 for ; Thu, 7 May 2020 21:06:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="JYC32j/t" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726701AbgEGVGO (ORCPT ); Thu, 7 May 2020 17:06:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726218AbgEGVGK (ORCPT ); Thu, 7 May 2020 17:06:10 -0400 Received: from mail-qk1-x743.google.com (mail-qk1-x743.google.com [IPv6:2607:f8b0:4864:20::743]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C215C05BD43 for ; Thu, 7 May 2020 14:06:10 -0700 (PDT) Received: by mail-qk1-x743.google.com with SMTP id s9so1320635qkm.6 for ; Thu, 07 May 2020 14:06:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=NEeebNbM/M0OFPawcEwiP7KQRHS26VREdoUS4zdOewE=; b=JYC32j/tVnDFyZT5cYi5BA4MS8gBSFnKpZe1g7y+WWKiAfQZ5EJtQTrCYRiguXAA2l 0vJ7cSu9q8Xr9H+/xflgKxprjziO6nUU0m7xAn8VfL6xKLvxxDNKL95b+nfZgyUxXtfY OYFZrMyS7894JTbZAsi9npqMeADUMfGvvSzL8mEc+eiwUY9CgOj9HYnA0M7QMYVPJTv7 Y2ciFMaL72giuvY6ENJegOReYfVmdOC34oZ8grdvBs6wYWx5dlara1Zb+FCCQLhN9OUv xNIpdubzwyETlxZKfGC0XPp7JAThtjvREjJjOUiA/Y7VelnvQgT1oEmJ4YrXFO9uLnnF s1Ew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=NEeebNbM/M0OFPawcEwiP7KQRHS26VREdoUS4zdOewE=; b=hZTiar3ySeGRRnOn3MbspsttONZ5Jnzm91t9fil/VeZOoDXI0j2nOaayBpETvqDRHU dXHpBr0FTbR8VF7H+PyIFYYtaGkcuXrw1u/fjMtK1wI4066RyeI0aX4eRTJ365VQlmNc wIUiLZb8Mzd32wxPy9T0/33gYvKNEzHW2OeSLwbDbj3IfZ9w6dY2Dbha8O66zaKqfgy0 oz0i1DEAq6eL2Qqj11PQ2DZFi1/075kio3Owp9PK/8HJZP6tUslYEXQj7yLAnrNF0cbz 0HmHVPEAP/vuWauDM+7wjfr4AMMZ7q+w1bMwrw7DUfHmR1d3MdzJAxqMzyoxlaQD6YqJ KrJw== X-Gm-Message-State: AGi0Pua3lJm8vtzN1pVzp7KAD4K06/hzURmGz8v7clajEO3MDpontUVZ BhMFrouQ6KIsKSlwcXKkBJPSVNo5a5g= X-Google-Smtp-Source: APiQypJsEx7aeCPdLDnanbySV4gX1hXU71wlsuantZoJhLj50yE07ICZgNKiJA9SVzPbUFe4vnX9lw== X-Received: by 2002:a37:6409:: with SMTP id y9mr16506966qkb.184.1588885569875; Thu, 07 May 2020 14:06:09 -0700 (PDT) Received: from localhost (70.44.39.90.res-cmts.bus.ptd.net. [70.44.39.90]) by smtp.gmail.com with ESMTPSA id x19sm4049983qkh.42.2020.05.07.14.06.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2020 14:06:09 -0700 (PDT) Date: Thu, 7 May 2020 17:05:53 -0400 From: Johannes Weiner To: Roman Gushchin Cc: Andrew Morton , Michal Hocko , linux-mm@kvack.org, kernel-team@fb.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo Message-ID: <20200507210553.GE161043@cmpxchg.org> References: <20200422204708.2176080-1-guro@fb.com> <20200422204708.2176080-11-guro@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200422204708.2176080-11-guro@fb.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 22, 2020 at 01:46:59PM -0700, 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