Date: Tue, 07 Jul 2020 17:12:44 +0000
From: bugzilla-noreply@freebsd.org
To: bugs@FreeBSD.org
Subject: [Bug 247829] Constant load of 1 on a recent 12.1-STABLE with 3 ZFS pools (high rates of zfskern{mmp_thread_enter})
Message-ID: <bug-247829-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D247829 Bug ID: 247829 Summary: Constant load of 1 on a recent 12.1-STABLE with 3 ZFS pools (high rates of zfskern{mmp_thread_enter}) Product: Base System Version: 12.1-STABLE Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: gbe@FreeBSD.org On a recent virtualized 12.1-STABLE build I see a constant load of 1. While investigating 'top -HS' it shows a relative high cpu usage for 'zfskern{mmp_thread_enter}', like in the example below. PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND 11 root 155 ki31 0B 64K CPU2 2 17:28 97.39% idle{idl= e: cpu2} 11 root 155 ki31 0B 64K CPU3 3 17:29 96.78% idle{idl= e: cpu3} 11 root 155 ki31 0B 64K CPU1 1 17:29 96.40% idle{idl= e: cpu1} 11 root 155 ki31 0B 64K RUN 0 17:25 96.13% idle{idl= e: cpu0} 8 root -8 - 0B 1040K mmp->m 2 0:44 4.32% zfskern{mmp_thread_enter} 8 root -8 - 0B 1040K mmp->m 1 0:44 4.28% zfskern{mmp_thread_enter} 8 root -8 - 0B 1040K mmp->m 3 0:44 4.25% zfskern{mmp_thread_enter} The problem at this point is that the relatively small CPU usage results in= a load=3D1.0, which let the host system schedule the assigned CPU cores of th= e VM at the highest possible clockrate. Trying OpenZFS seems to improve the situation, but I am not sure that this = is completely true, since only my zroot pool was detected and the two other po= ols weren't. --=20 You are receiving this mail because: You are the assignee for the bug.=
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