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charset=us-ascii Content-Disposition: inline In-Reply-To: <20230301193403.1507484-1-surenb@google.com> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 835191C0016 X-Stat-Signature: ruj5j71xk91mjp1jj6cm1u5dr8iqa55p X-Rspam-User: X-HE-Tag: 1677765507-496315 X-HE-Meta: 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 2yZ4cIqP QYEaoMxuvIJCUEdTbcC38sV7eSnn+wXFCWFLro+ukVqQY6UE14QEIa2/TBST6xejCLQSIkqEiOerDPILrm/6HqI2COpwk+egGwHJCSWU5DrXZLJaj+F2YJGyKTB0Tr+i6vARIbE8EiELwN6GfRJSRkAvsky3y9Kkvx7A3S9nFnZ9gC7YaonI0HfNuUa1QAeRLCHsuOk8+WIRIteZSTiRb46Z5CE/DnFPtOlGXXzN03CczcmnhUBUx3EKkYFkMczp9fOf9F+tTv0PtxIWSkEjB1Xwg0yDbxgJ7yYx4i/WGDNuuIbS2M1BMk4nzfig8XQ4rPrdDS3mnOEcLCWWrodXhvJME3jq4oo9OYw9vlnXQiWDMd7vS49Vey/nzdQ== 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: On Wed 01-03-23 11:34:03, Suren Baghdasaryan wrote: > Current 500ms min window size for psi triggers limits polling interval > to 50ms to prevent polling threads from using too much cpu bandwidth by > polling too frequently. However the number of cgroups with triggers is > unlimited, so this protection can be defeated by creating multiple > cgroups with psi triggers (triggers in each cgroup are served by a single > "psimon" kernel thread). > Instead of limiting min polling period, which also limits the latency of > psi events, it's better to limit psi trigger creation to authorized users > only, like we do for system-wide psi triggers (/proc/pressure/* files can > be written only by processes with CAP_SYS_RESOURCE capability). This also > makes access rules for cgroup psi files consistent with system-wide ones. > Add a CAP_SYS_RESOURCE capability check for cgroup psi file writers and > remove the psi window min size limitation. > > Suggested-by: Sudarshan Rajagopalan > Link: https://lore.kernel.org/all/cover.1676067791.git.quic_sudaraja@quicinc.com/ > Signed-off-by: Suren Baghdasaryan Acked-by: Michal Hocko with this to fix [...] > @@ -1278,8 +1277,7 @@ struct psi_trigger *psi_trigger_create(struct psi_group *group, > if (state >= PSI_NONIDLE) > return ERR_PTR(-EINVAL); > > - if (window_us < WINDOW_MIN_US || > - window_us > WINDOW_MAX_US) > + if (window_us <= 0 || window_us > WINDOW_MAX_US) > return ERR_PTR(-EINVAL); window_us is u32 sp the check for <= 0 doesn't make any sense. > > /* Check threshold */ > -- > 2.40.0.rc0.216.gc4246ad0f0-goog -- Michal Hocko SUSE Labs