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[141.239.149.160]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1fc0bc52bbcsm78305985ad.291.2024.07.17.11.57.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Jul 2024 11:57:05 -0700 (PDT) Sender: Tejun Heo Date: Wed, 17 Jul 2024 08:57:04 -1000 From: "tj@kernel.org" To: Waiman Long Cc: Boy Wu =?utf-8?B?KOWQs+WLg+iqvCk=?= , "boris@bur.io" , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "cgroups@vger.kernel.org" , "linux-mediatek@lists.infradead.org" , "axboe@kernel.dk" , Iverlin Wang =?utf-8?B?KOeOi+iLs+mclik=?= , "josef@toxicpanda.com" , "linux-arm-kernel@lists.infradead.org" , "matthias.bgg@gmail.com" , "angelogioacchino.delregno@collabora.com" Subject: Re: [PATCH v3] blk-cgroup: Replace u64 sync with spinlock for iostat update Message-ID: References: <5560c690cc6de67139a9b2e45c7a11938b70fc58.camel@mediatek.com> <1b19b68adb34410bf6dc8fd3f50e4b82c1a014e4.camel@mediatek.com> <134fc34c-10b8-4d00-aaca-8285efce9899@redhat.com> <48fa8bc9-9f8d-4406-9137-88a555883ea2@redhat.com> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <48fa8bc9-9f8d-4406-9137-88a555883ea2@redhat.com> On Wed, Jul 17, 2024 at 02:55:37PM -0400, Waiman Long wrote: > I was wrong about __blkcg_rstat_flush(). Right, the main updater of > iostat_cpu is  blk_cgroup_bio_start(). We do need to drop down some comment > on what is protected by u64_sync and what is by blkg_stat_lock though. It > can be confusing. Oh yeah, definitely. It is confusing. -- tejun