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b=fgsqbEFJMphC0NO85sA0hK3dRmiHLIn/+JEvZ3VNUypK1t9a27aQIRKldS2AIQWG/ xTmKizpo38V3KcPQlAv0MBFChHJj/8tvP3MjynQHl/gUa64CqW04pAZcWQIpdtGdi9 yZXTEiFhaFLoHiHajZsYX9m/HefGnzDlKh0s9ccLHTzs2TSQubV2ClWlJQqvYm6omo JCncODigKLKHXsclYZtW7jiKhNyZi1NXfPtqvC//DE8IflhspoIyMqApPhVQr//Uqa 2BjTHt1tIBdlDJ1onQo57zNspzMUI00kkpVTWvM+Ox9sT9gqHCI6QKLYUz37seWjI8 Euakf0dOf3yIA== From: SeongJae Park To: Gutierrez Asier Cc: SeongJae Park , akpm@linux-foundation.org, damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, wangkefeng.wang@huawei.com, artem.kuzin@huawei.com, stepanov.anatoly@huawei.com Subject: Re: [RFC PATCH v1] mm: improve call_controls_lock Date: Tue, 30 Dec 2025 21:01:37 -0800 Message-ID: <20251231050138.77727-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <4b367446-2248-4936-99b6-e9ee93298eb5@huawei-partners.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 0ED15C0013 X-Stat-Signature: hm6c868jr7st9w53whm5jpso169yspd1 X-Rspam-User: X-HE-Tag: 1767157303-892203 X-HE-Meta: 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 yjqYxM8h DQcrk 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 Tue, 30 Dec 2025 12:02:31 +0300 Gutierrez Asier wrote: > > > On 12/29/2025 6:22 PM, SeongJae Park wrote: > > Hello Asier, > > Hi SeongJae, > > > > > Thank you for sending this patch! > > > > On Mon, 29 Dec 2025 14:55:32 +0000 Asier Gutierrez wrote: > > > >> This is a minor patch set for a call_controls_lock synchronization improvement. > > > > Please break description lines to not exceed 75 characters per line. > > > >> > >> Spinlocks are faster than mutexes, even when the mutex takes the fast > >> path. Hence, this patch replaces the mutex call_controls_lock with a spinlock. > > > > But call_controls_lock is not being used on performance critical part. > > Actually, most of DAMON code is not performance critical. I really appreciate > > your patch, but I have to say I don't think this change is really needed now. > > Please let me know if I'm missing something. > > I was just reviewing the code and I noticed this. Yes, you are right, the performance > is not critical. Thank you for flexibly accepting my humble opinion. > > >> > >> Initial benchmarking shows the following results > >> > >> > >> # bpftrace -e 'kprobe:kdamond_call { @start[tid] = nsecs; } > > > > Commit log shouldn't start with '#'. Please consider indenting the above > > command and below outputs of it. > > > > > > Thanks, > > SJ > > > > [...] > > > > Thanks a lot for the review! My pleasure! Looking forward to your next patch :) Thanks, SJ [...]