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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 9DA2FC433FE for ; Thu, 10 Dec 2020 10:10:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A9BC23B31 for ; Thu, 10 Dec 2020 10:10:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728164AbgLJKKN (ORCPT ); Thu, 10 Dec 2020 05:10:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:55634 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726313AbgLJKKM (ORCPT ); Thu, 10 Dec 2020 05:10:12 -0500 Date: Thu, 10 Dec 2020 11:10:45 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1607594972; bh=J7sv2iFrStp06XrBmboT+zD64Wiv3fsbAwBnnf2rAFs=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=bh+goS4FrXP8/1kzLZDnLmQaoSt40yDsiBv/vec2SlhlXrPButujZB4EfKWJWFJQC GAFU/CVWCR6oknslGQ/DcIShKbeXC54JQqn328saa07awYE2Rzzq9sewvgYlzyh6Ic DC4j7g3W/LaqI33bDAcKBenlrJCsCLMeSflCicR8= From: Greg KH To: Christian =?iso-8859-1?Q?K=F6nig?= Cc: Hridya Valsaraju , Sumit Semwal , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, kernel-team@android.com, surenb@google.com, john.stultz@linaro.org Subject: Re: [PATCH] dmabuf: Add the capability to expose DMA-BUF stats in sysfs Message-ID: References: <20201210044400.1080308-1-hridya@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 10, 2020 at 10:58:50AM +0100, Christian König wrote: > In general a good idea, but I have a few concern/comments here. > > Am 10.12.20 um 05:43 schrieb Hridya Valsaraju: > > This patch allows statistics to be enabled for each DMA-BUF in > > sysfs by enabling the config CONFIG_DMABUF_SYSFS_STATS. > > > > The following stats will be exposed by the interface: > > > > /sys/kernel/dmabuf//exporter_name > > /sys/kernel/dmabuf//size > > /sys/kernel/dmabuf//dev_map_info > > > > The inode_number is unique for each DMA-BUF and was added earlier [1] > > in order to allow userspace to track DMA-BUF usage across different > > processes. > > > > Currently, this information is exposed in > > /sys/kernel/debug/dma_buf/bufinfo. > > However, since debugfs is considered unsafe to be mounted in production, > > it is being duplicated in sysfs. > > Mhm, this makes it part of the UAPI. What is the justification for this? > > In other words do we really need those debug information in a production > environment? Production environments seem to want to know who is using up memory :)