Date: Sun, 27 Apr 2014 08:20:53 -0700 From: Peter Grehan <grehan@freebsd.org> To: Oleg Ginzburg <olevole@olevole.ru> Cc: freebsd-virtualization@freebsd.org Subject: Re: bhyve behavior under cpuset_setaffinity Message-ID: <535D2055.6060107@freebsd.org> In-Reply-To: <11465971.5E2sZFzEpK@kde4.my.domain> References: <11465971.5E2sZFzEpK@kde4.my.domain>
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Hi Oleg, > For example by executing follow command on bhyve pid: > > % cpuset -l 2 -p 3476 > 3476 vcpu 0 RET ioctl 0 ... > 3476 vcpu 1 RET ioctl 0 Looks like you have a 2 vCPU guest, but the cpuset only contains a single host CPU. What happens here under load is that you will start hitting "lock-holder preemption", where a vCPU can be preempted while holding a lock, and the other vCPU will spin trying to acquire it. Using the "-P" option with bhyve will help this somewhat, though I'd recommend using >= 2 CPUs with the cpuset command. later, Peter.
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