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From: Shakeel Butt To: Jianyue Wu Cc: Andrew Morton , linux-mm@kvack.org, cgroups@vger.kernel.org, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, muchun.song@linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] mm: optimize stat output for 11% sys time reduce Message-ID: References: <20260110042249.31960-1-jianyuew@nvidia.com> <20260110153342.7e689e794ce43a0a39c699fc@linux-foundation.org> <7210e5e0-2a93-4d3b-a564-85c0fe117ef5@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7210e5e0-2a93-4d3b-a564-85c0fe117ef5@gmail.com> X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 3175240005 X-Rspam-User: X-Stat-Signature: 5hzbz6bn56xe31bbddfri9fdc8jskdjz X-HE-Tag: 1768263805-460150 X-HE-Meta: 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 aH+7Vk+f kkGLi9kSfspnCj7VnNbRi3w04pljLkuv9fkNVmORc08kW00qJb9wJzT0qprgJfZKLxRs2nEu4SKib8r8FprTADMq0gp1cqJK3UxkT0Feo3LCkD/6+YEweKpIROltlzqz+HYXBKAtLxuGcFOEdaHEhktTizhwrCGRJhUa5/enRuMfNxBVEwRRw8WKcoNI21WoiqUEx854b56dfGk3tC781zKuDQw8W/LFl3CYCtdZHDP3CtGIo49E4foD7gX7lfj5ZbAITE8c1VLusCBYX7YfFofmwfQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, Jan 11, 2026 at 12:37:45PM +0800, Jianyue Wu wrote: > On 1/11/2026 7:33 AM, Andrew Morton wrote: > > On Sat, 10 Jan 2026 12:22:49 +0800 Jianyue Wu wrote: > > > > > Replace seq_printf/seq_buf_printf with lightweight helpers to avoid > > > printf parsing in memcg stats output. > > > > > I don't understand - your previous email led me to believe that the new > > BPF interface can be used to address this issue? > > Yes, previously I think can directly use BPF interface to speedup. Later I > think maybe this is still needed, as some platform didn't have BPF installed > might still use these sysfs files. > It seems like this patch adds measurable improvement for the traditional stat readers. The high performance ones can be switched to the bpf based interface. So, I see no harm in taking this patch in.