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charset=us-ascii Content-Disposition: inline In-Reply-To: <20230203232409.163847-3-frederic@kernel.org> X-Rspam-User: X-Rspamd-Queue-Id: 4474014001E X-Rspamd-Server: rspam01 X-Stat-Signature: ay1nd73cwgdhdbpn93d15k5meucnm73n X-HE-Tag: 1676295268-16278 X-HE-Meta: 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 qIyMWoUA q0eyFBsqH1OydFiae+2rJbqkI8TTC1StdpopkObiv0TmNsvmU+bdLfEhwh4UauwQiNv4LlFIz/UjFG9J+sO56I66SK9Bo2XKIBj2Rv2tid1t9muqhCLHYRVvxrYLibg1DnANhuS6ZjkZGWB1X33DahvxB3lJw/wSXlsJFcPbvU9qunnpWNO4CVjfu+iyD+2Uclm8RUrFgZPEFzQtEMkujrynlL37UGRiE2mmHYgRoZAbT1gbOQxCHdFbaz4kZLCP5ivqsdpvL1MJgBUG1TWachcvQj/4omcdsLOaOhZ8UXuGgu8+SERLfad2qlAXJeIehg+4prXllpC6OG4w= 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 Sat 04-02-23 00:24:09, Frederic Weisbecker wrote: > Provide this new API to check if a CPU has been isolated either through > isolcpus= or nohz_full= kernel parameter. > > It aims at avoiding kernel load deemed to be safely spared on CPUs > running sensitive workload that can't bear any disturbance, such as > pcp cache draining. > > Suggested-by: Michal Hocko > Signed-off-by: Frederic Weisbecker Is there any locking required? I do not think so as these should be boot time configured AFAIR. From the discussion around this I have understood that this might change in the future once cpusets gain a better isolation support. Maybe this should be documented at this stage? Thanks! > --- > include/linux/sched/isolation.h | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h > index b645cc81fe01..088672f08469 100644 > --- a/include/linux/sched/isolation.h > +++ b/include/linux/sched/isolation.h > @@ -53,4 +53,10 @@ static inline bool housekeeping_cpu(int cpu, enum hk_type type) > return true; > } > > +static inline bool cpu_is_isolated(int cpu) > +{ > + return !housekeeping_test_cpu(cpu, HK_TYPE_DOMAIN) || > + !housekeeping_test_cpu(cpu, HK_TYPE_KERNEL_NOISE); > +} > + > #endif /* _LINUX_SCHED_ISOLATION_H */ > -- > 2.34.1 -- Michal Hocko SUSE Labs