Date: Fri, 28 Oct 2005 18:43:10 +0800 From: David Xu <davidxu@freebsd.org> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: Pertti Kosunen <pertti.kosunen@pp.nic.fi>, current@freebsd.org, "Yuriy N. Shkandybin" <jura@networks.ru> Subject: Re: Timers and timing, was: MySQL Performance 6.0rc1 Message-ID: <436200BE.70604@freebsd.org> In-Reply-To: <31129.1130495688@critter.freebsd.dk> References: <31129.1130495688@critter.freebsd.dk>
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Poul-Henning Kamp wrote: > In message <4361FDBE.7000500@freebsd.org>, David Xu writes: > > > the correct way to optimize this would be to add a time(2) systemcall > which returns the value of the kernel global time_second. > Can we make a page in kernel address space which is readable my user code? put the variable in the page, I know read an integer is atomic-op, needn't lock, so syscall is not needed.
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