Date: Wed, 29 Jun 2022 21:14:03 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 264867] kevent EVFILT_TIMER, timer expiration with twice the period Message-ID: <bug-264867-227-74oohqE2AS@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-264867-227@https.bugs.freebsd.org/bugzilla/> References: <bug-264867-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D264867 --- 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= .=20 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 w= hy kevent does this, it doesn't make much sense to me. If I change filt_timertouch() to set kc->cpuid =3D PCPU_GET(cpuid) each tim= e 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? --=20 You are receiving this mail because: You are the assignee for the bug.=
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