Date: Sun, 24 Jun 2001 17:41:38 -0400 From: "Brian F. Feldman" <green@FreeBSD.org> To: "Jonathan Lemon <jlemon@flugsvamp.com> Alfred Perlstein" <bright@sneakerz.org> Cc: Mike Silbersack <silby@silby.com>, Matt Dillon <dillon@earth.backplane.com>, Mike Silbersack <silby@FreeBSD.org>, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org, jlemon@FreeBSD.org, bmilekic@FreeBSD.org Subject: Re: cvs commit: src/sys/netinet tcp_input.c tcp_output.c tcp_subr.c tcp_timer.c tcp_usrreq.c tcp_var.h Message-ID: <200106242141.f5OLfc176777@green.bikeshed.org> In-Reply-To: Message from "Jonathan Lemon <jlemon@flugsvamp.com> Alfred Perlstein" <bright@sneakerz.org> of "Sun, 24 Jun 2001 13:58:28 CDT." <20010624135828.A64836@sneakerz.org>
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"Jonathan Lemon <jlemon@flugsvamp.com> Alfred Perlstein" <bright@sneakerz.org> wrote: > * Mike Silbersack <silby@silby.com> [010623 13:14] wrote: > > > > On Sat, 23 Jun 2001, Matt Dillon wrote: > > > > > Yes, there's no question bzero() should be removed. The subroutine > > > overhead alone, never mind it doing anything, is enough to blow away > > > any benefit. Hence: > > > > > > Test3 - man load w/ptrs 35.73 nS/loop > > > Test4 - mlptrs & bzero 161.60 nS/loop > > > > > > Ouch! Of course, us old timers also see the fact that the entire > > > subroutine runs dozens of instructions in less then a microsecond and > > > say "ooooh, cool...". > > > > > > -Matt > > > > Wow! Thanks for the optimization, I hadn't considered that bzero could be > > so slow. > > > > I'm about to take off right now, I'll see if I can mock up some benchmarks > > of the overall performance of tcp_output when I get back on Monday. > > bzero seems to be optimized for large areas, perhaps it would help > malloc some if we used some alternative zero'ing function for small > allocations with M_ZERO set? That's pretty pointless; M_ZERO is _supposed_ to eventually be providing pre-zeroed memory, which should remove that bzero in the general case, anyway. -- Brian Fundakowski Feldman \ FreeBSD: The Power to Serve! / green@FreeBSD.org `------------------------------' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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