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Howlett" , Brendan Jackman , David Hildenbrand , Johannes Weiner , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , Zi Yan , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-team@meta.com Subject: Re: [PATCH v3 1/3] mm/page_alloc/vmstat: Simplify refresh_cpu_vm_stats change detection Date: Fri, 10 Oct 2025 11:30:29 -0700 Message-Id: <20251010183029.68434-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20251002204636.4016712-2-joshua.hahnjy@gmail.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: ox8msbwdwuxcn8sfnqccxyb9rq9jupmd X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 49224120005 X-HE-Tag: 1760121033-976484 X-HE-Meta: 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 jfz6Rh7t rC6kfq4Z7MJo01KJwgaC8ktmVwRTfbZ2qVyMz91wDGZO1YKh0jIJLOfSFNbb0IAQREOMJMru/Zxt97Zl4/uZYen91pUmZkT6qfIUWB6f89B4kYQgqJSfu+4xfvsUO8JJI4IAnX2rbn/ClWFPhHt6F1vXiPskfOUDCCjSojT93EKvb7x2Koo856qoiR3bCgUiuQZZ8thrX8UI2/hAtZc7D5MOALeZFmY5ZkWVPpc9KT4wlkKkqxqceG89VWCQ+B7jUrako/PqntfI+dAYhlmPCbSCnQGDtzmrmPwZpJYU/gSYMLJNFEoVNrnE8t5T9FolJGFarKthf0f2pz7I7muyEkv4T9r93bynTDNDZ9KCqf7KLX1+fOy7R6wuRrA== 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 Thu, 2 Oct 2025 13:46:31 -0700 Joshua Hahn wrote: > Currently, refresh_cpu_vm_stats returns an int, indicating how many > changes were made during its updates. Using this information, callers > like vmstat_update can heuristically determine if more work will be done > in the future. > > However, all of refresh_cpu_vm_stats's callers either (a) ignore the > result, only caring about performing the updates, or (b) only care about > whether changes were made, but not *how many* changes were made. > > Simplify the code by returning a bool instead to indicate if updates > were made. > > In addition, simplify fold_diff and decay_pcp_high to return a bool > for the same reason. > > Signed-off-by: Joshua Hahn Reviewed-by: SeongJae Park Thanks, SJ [...]