Date: Mon, 27 Oct 2008 06:25:02 +0000 (UTC) From: Maxim Sobolev <sobomax@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/kern subr_param.c Message-ID: <200810270625.m9R6P7q1047096@repoman.freebsd.org>
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sobomax 2008-10-27 06:25:02 UTC FreeBSD src repository Modified files: sys/kern subr_param.c Log: SVN rev 184323 on 2008-10-27 06:25:02Z by sobomax Default HZ value (1,000) on i386/amd64 is not very virtual machine friendly. Due to the nature of the beast it causes lot of unproductive overhead. This is especially bad when running SMP kernel on VMWare with several virtual processors - idle FreeBSD guest with SMP kernel takes 150% host CPU time on my dual-core MacBook Pro when I am enabling two virtual CPUs, making even host not very usable. Detect when we are running in the sandbox and reduce HZ to 10 (can be adjusted via VM_HZ in the kernel config) in such cases. This brings host CPU usage of idle FreeBSD/SMP on two virtual processors down to 10%. Detect most popular VM platforms out there - VMWare, Parallels, VirtualBox and VirtualPC. MFC after: 2 weeks Revision Changes Path 1.77 +39 -1 src/sys/kern/subr_param.c
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