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=243212 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 domains? - 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 allocations 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 the 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. -- You are receiving this mail because: You are the assignee for the bug.help
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