Date: Thu, 6 Feb 2003 08:50:12 -0800 (PST) From: Arun Sharma <arun@sharma-home.net> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/18524: The current kernel doesn't keep stats on a per c Message-ID: <200302061650.h16GoCgn021587@freefall.freebsd.org>
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The following reply was made to PR kern/18524; it has been noted by GNATS. From: Arun Sharma <arun@sharma-home.net> To: John Baldwin <jhb@FreeBSD.org> Cc: smp@freebsd.org, freebsd-gnats-submit@FreeBSD.org Subject: Re: kern/18524: The current kernel doesn't keep stats on a per c Date: Thu, 6 Feb 2003 08:50:49 -0800 On Thu, Feb 06, 2003 at 11:13:15AM -0500, John Baldwin wrote: > > and submit a new patch: > > > > http://www.sharma-home.net/~adsharma/misc/pcpu-cptime.patch > > [...] > > Why not stick the cp_time stuff in struct pcpu instead of using an > array? The new patch _is_ putting cp_time in struct pcpu. The old patch in the PR predates struct pcpu. I also chose to leave the existing cp_time alone. One could argue that a user level tool could sum up the pcpu cp_times to derive the cp_time and the kernel can avoid dirtying an extra cache line. If people feel strongly about it, I can skip touching cp_time in the SMP case. It's a choice between compatibility with UP vs performance. -Arun To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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