Date: Thu, 30 Oct 2008 13:20:34 +0100 From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no> To: Maxim Sobolev <sobomax@FreeBSD.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r184323 - head/sys/kern Message-ID: <86wsfqgtpp.fsf@ds4.des.no> In-Reply-To: <200810270625.m9R6P2a8029701@svn.freebsd.org> (Maxim Sobolev's message of "Mon, 27 Oct 2008 06:25:02 %2B0000 (UTC)") References: <200810270625.m9R6P2a8029701@svn.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Maxim Sobolev <sobomax@FreeBSD.org> writes: > Log: > Default HZ value (1,000) on i386/amd64 is not very virtual machine frie= ndly. > 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 tim= e 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. T= his > brings host CPU usage of idle FreeBSD/SMP on two virtual processors down > to 10%. What, too chicken to go whole hog and make the kernel tickless? :) DES --=20 Dag-Erling Sm=C3=B8rgrav - des@des.no
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?86wsfqgtpp.fsf>