Date: Thu, 5 Oct 2000 04:58:43 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: bde@zeta.org.au (Bruce Evans) Cc: dillon@earth.backplane.com (Matt Dillon), peter@netplex.com.au (Peter Wemm), cp@bsdi.com (Chuck Paterson), bright@wintelcom.net (Alfred Perlstein), jhb@FreeBSD.ORG (John Baldwin), arch@FreeBSD.ORG, jdp@polstra.com (John Polstra), eischen@vigrid.com (Daniel Eischen), grog@lemis.com (Greg Lehey) Subject: Re: Mutexes and semaphores Message-ID: <200010050458.VAA07440@usr07.primenet.com> In-Reply-To: <Pine.BSF.4.21.0010051216130.12069-100000@besplex.bde.org> from "Bruce Evans" at Oct 05, 2000 12:40:16 PM
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> This seems to be only to win getppid() benchmarks. Complications like it > might be justified in inner loops of syscalls that are called somewhat > more than once at most in normal programs. It's too hard to do things > this in the thousands of places that would be necessary to get a uniform > speedup. Well screw that, that's not the way to win getppid() benchmarks! The real way to cheat is to double map a read-only page into user space from kernel space, and have it just dereference a pid_t * into the relevent page. I even know a UNIX that did this, once upon a time... Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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