Messages in this thread | | | Subject | Re: [PATCH] kallsyms: Fix sleeping function called from invalid context when CONFIG_KALLSYMS_SELFTEST=y | From | "Leizhen (ThunderTown)" <> | Date | Tue, 27 Dec 2022 15:16:31 +0800 |
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On 2022/12/21 20:37, Leizhen (ThunderTown) wrote: >>>> I am not familiar with it. But task_cputime() in >>>> kernel/sched/cputime.c looks promising. And there must be >>>> the interface how the user space get this information. >>>> Some is available via /proc/<PID>/... I am not sure >>>> if there is a syscall. >> Please, try to investigate the above hints. > Yes, I will. Thanks.
Function task_cputime() works well when CONFIG_VIRT_CPU_ACCOUNTING_GEN=y, but not when CONFIG_TICK_CPU_ACCOUNTING=y. The latter seems to be based on tick interrupt sampling, rather than recording timestamps during task switches.
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-- Regards, Zhen Lei
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