From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maarten Lankhorst Subject: Re: [Linaro-mm-sig] [PATCH] dma-buf: Add debugfs support Date: Fri, 14 Dec 2012 12:57:54 +0100 Message-ID: <50CB1442.50002@gmail.com> References: <1355477817-5750-1-git-send-email-sumit.semwal@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1355477817-5750-1-git-send-email-sumit.semwal@ti.com> Sender: linux-media-owner@vger.kernel.org To: sumit.semwal@ti.com Cc: sumit.semwal@linaro.org, linaro-mm-sig@lists.linaro.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org List-Id: dri-devel@lists.freedesktop.org Op 14-12-12 10:36, sumit.semwal@ti.com schreef: > From: Sumit Semwal > > Add debugfs support to make it easier to print debug information > about the dma-buf buffers. > I like the idea, I don't know if it could be done in a free manner, but for bonus points could we also have the dma-buf fd be obtainable that way from a debugfs entry? Doing so would allow me to 'steal' a dma-buf from an existing mapping easily, and test against that. Also I think the name of the device and process that exported the dma-buf would be useful to have as well, even if in case of the device that would mean changing the api slightly to record it. I was thinking of having a directory structure like this: /sys/kernel/debug/dma_buf/stats and then for each dma-buf: /sys/kernel/debug/dma-buf/exporting_file.c/-fd /sys/kernel/debug/dma-buf/exporting_file.c/-attachments /sys/kernel/debug/dma-buf/exporting_file.c/-info Opening the fd file would give you back the original fd, or fail with -EIO if refcount was dropped to 0. Would something like this be doable? I don't know debugfs that well, but I don't see why it wouldn't be, ~Maarten