[Bug 264867] kevent EVFILT_TIMER, timer expiration with twice the period
Date: Wed, 29 Jun 2022 21:14:03 UTC
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=264867 --- Comment #6 from Mark Johnston <markj@FreeBSD.org> --- To expand on my question a bit, I think there is a race somewhere in the eventtimer code which occurs when a callout is scheduled on a different CPU. In particular, when an EVFILT_TIMER event is created, it is "pinned" to the current CPU, and all future callouts will fire on the CPU. I am not sure why kevent does this, it doesn't make much sense to me. If I change filt_timertouch() to set kc->cpuid = PCPU_GET(cpuid) each time the event is re-added, then the bug is much harder to trigger. Alternately, if the test is changed so that each thread pins itself to a different CPU, then the problem is not reproducible for me. (In reply to felice.tufo from comment #4) Does your test module specify the target CPU when arming a callout? -- You are receiving this mail because: You are the assignee for the bug.