Date: Wed, 29 Mar 2000 16:38:18 -0800 From: Mike Smith <msmith@freebsd.org> To: Mike Smith <msmith@freebsd.org> Cc: Matthew Dillon <dillon@apollo.backplane.com>, freebsd-current@freebsd.org Subject: Re: SMP buildworld times / performance tests Message-ID: <200003300038.QAA08006@mass.cdrom.com> In-Reply-To: Your message of "Wed, 29 Mar 2000 16:33:36 PST." <200003300033.QAA07919@mass.cdrom.com>
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> > For the single-process (1-fork) case, syscall overhead improved > > moderately from 1.6 uS in 4.0 to 1.3 uS in 5.0. I think the marked > > improvement in the competing-cpu's case is due to the movement of the > > MP lock inward somewhat (even for syscalls that aren't MP safe), > > the removal of a considerable number of unnecessary 'lock'ed instructions, > > and the removal of the cpl lock (which benefits spl*() code as well as > > syscall/interrupt code). > > > > I got similar results for calling sigprocmask(): > > You should be able to remove the splhigh() from sigprocmask and run it > MPSAFE. At least, I can't find a reason not to (and it works here, yes). Just following on from this, one thing that I can see immediately being very important to me at least is a spinlock in the timecounter structure. Calcru and various other things call microtime(), and we're going to want to lock out updates and parallel accesses to the timecounter. What should we be using for an interrupt-disabling spinlock? -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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