Date: Sun, 24 Jun 2001 13:58:28 -0500 From: "Jonathan Lemon <jlemon@flugsvamp.com> Alfred Perlstein" <bright@sneakerz.org> To: Mike Silbersack <silby@silby.com> Cc: 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: <20010624135828.A64836@sneakerz.org> In-Reply-To: <20010623131152.I23528-100000@achilles.silby.com>; from silby@silby.com on Sat, Jun 23, 2001 at 01:14:11PM -0500 References: <200106231730.f5NHUNd73058@earth.backplane.com> <20010623131152.I23528-100000@achilles.silby.com>
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* 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? -Alfred To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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