Date: Thu, 09 Jan 2020 15:56:49 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 243212] High CPU usage when set affinity on multiple CPU Message-ID: <bug-243212-227-sFEyfS7oM7@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-243212-227@https.bugs.freebsd.org/bugzilla/> References: <bug-243212-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D243212 Mark Johnston <markj@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |markj@FreeBSD.org --- Comment #2 from Mark Johnston <markj@FreeBSD.org> --- > I guess that this regression has something to do with NUMA, maybe threads= 4,5 are forced to use memory domain 0, causing the additional CPU usage. The policy as reported by cpuset is first-touch, meaning that threads will attempt to allocate memory from the local domain first. Some things you could try to help narrow the problem down: - Look at memory utilization. Do you have lots of free memory in both doma= ins? - Collect a flamegraph using https://github.com/brendangregg/FlameGraph to = see where the high system CPU time is coming from. - Try other domain allocation policies. round-robin will cause threads to alternate between the two domains. You can also try forcing all allocation= s to come from domain 0, where most of the threads are running. - Try disabling thread pinning. - Try setting the vm.numa.disabled tunable to 1. I think this will force t= he page allocator to behave the same as it would in 11.3, so you can rule out other differences between 11.3 and 12.1 that might be causing a problem. --=20 You are receiving this mail because: You are the assignee for the bug.=
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