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Tue, 18 Aug 2026 16:02:01 -0700 (PDT) Date: Tue, 18 Aug 2026 16:01:58 -0700 From: Ziyang Men To: Tejun Heo Cc: kernel-team@meta.com, Jens Axboe , Josef Bacik , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Shuah Khan , Johannes Weiner , Michal =?iso-8859-1?Q?Koutn=FD?= , Roman Gushchin , Shakeel Butt , JP Kobryn , Mykola Lysenko , linux-block@vger.kernel.org, bpf@vger.kernel.org, cgroups@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] block: add BPF kfuncs to read blkcg io.stat Message-ID: References: <20260817214205.723267-1-ziyang.meme@gmail.com> <20260817214205.723267-2-ziyang.meme@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: Hi Tejun, On Tue, Aug 18, 2026 at 12:42:54PM -1000, Tejun Heo wrote: >On Tue, Aug 18, 2026 at 03:31:29PM -0700, Ziyang Men wrote: >> Ok I will add the casts bpf_get_blkcg() and bpf_put_blkcg(), and remove the >> check of css->ss in above functoins. > >RCU_PROTECTED is probably better than get/put(). Yes we can make the blkcg* RCU_PROTECTED but then the bpf_blkcg_flush_stats() needs to take the @cgroup* since it is SLEEPABLE. Does this work for you? Best, Ziyang > >Thanks. > >-- >tejun