linux-kernel - Re: [PATCH] dma-buf: Remove DMA-BUF sysfs stats

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CABdmKX3LGWueY91k+i7_WFTC8b8LJdR8nj6Y9KeJMRk7fSrsww@mail.gmail.com>
Date: Tue, 20 Jan 2026 13:56:02 -0800
From: "T.J. Mercier" <tjmercier@...gle.com>
To: Sumit Semwal <sumit.semwal@...aro.org>
Cc: Christian König <christian.koenig@....com>, 
	Jonathan Corbet <corbet@....net>, linux-kernel@...r.kernel.org, linux-media@...r.kernel.org, 
	dri-devel@...ts.freedesktop.org, linaro-mm-sig@...ts.linaro.org, 
	linux-doc@...r.kernel.org
Subject: Re: [PATCH] dma-buf: Remove DMA-BUF sysfs stats

On Mon, Jan 19, 2026 at 5:08 AM Sumit Semwal <sumit.semwal@...aro.org> wrote:
>
> Hi T J,
>
> On Mon, 19 Jan 2026 at 15:15, Christian König <christian.koenig@....com> wrote:
> >
> > On 1/16/26 20:05, T.J. Mercier wrote:
> > > Commit bdb8d06dfefd ("dmabuf: Add the capability to expose DMA-BUF stats
> > > in sysfs") added dmabuf statistics to sysfs in 2021 under
> > > CONFIG_DMABUF_SYSFS_STATS. After being used in production, performance
> > > problems were discovered leading to its deprecation in 2022 in commit
> > > e0a9f1fe206a ("dma-buf: deprecate DMABUF_SYSFS_STATS"). Some of the
> > > problems with this interface were discussed in my LPC 2025 talk. [1][2]
> > >
> > > Android was probably the last user of the interface, which has since
> > > been migrated to use the dmabuf BPF iterator [3] to obtain the same
> > > information more cheaply. As promised in that series, now that the
> > > longterm stable 6.18 kernel has been released let's remove the sysfs
> > > dmabuf statistics from the kernel.
> > >
> > > [1] https://www.youtube.com/watch?v=D83qygudq9c
> > > [2] https://lpc.events/event/19/contributions/2118/
> > > [3] https://lore.kernel.org/all/20250522230429.941193-1-tjmercier@google.com/
> > >
> > > Signed-off-by: T.J. Mercier <tjmercier@...gle.com>
> >
> > Oh yes please :)
> >
> > Reviewed-by: Christian König <christian.koenig@....com>
> Thank you for your patch, LGTM :)
>
> If its not pushed yet, I'll push it tonight.
>
> Best,
> Sumit

Thanks Sumit and Christian!