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Date: Tue, 26 Jun 2001 11:23:23 -0700 (PDT)
From: Matt Dillon <dillon@earth.backplane.com>
Message-Id: <200106261823.f5QINNM26741@earth.backplane.com>
To: "Jonathan Lemon <jlemon@flugsvamp.com>    Alfred Perlstein" <bright@sneakerz.org>
Cc: Poul-Henning Kamp <phk@critter.freebsd.dk>,
	"Brian F. Feldman" <green@FreeBSD.org>,
	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
References: <200106261707.f5QH70k41274@green.bikeshed.org> <75438.993576676@critter> <20010626123610.M64836@sneakerz.org>
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:...
:> some particular case of allocation you need the speed of the
:> optimized bzero().
:> 
:> But if you need the optimized bzero() that bad, what are you
:> doing calling malloc in the first place ?
:
:We could put the test for size in the macro portion then deciding
:to M_ZERO or not along with which version would be optimized out
:by the compiler for constants.
:
:-Alfred

    Yah, but I'm not sure its worth the effort to inline-optimize malloc()
    if prezeroing is added.  I can see the advantage of optimizing stand-alone
    bzero() calls, but inlining certain cases of malloc(M_ZERO) will bloat
    the codebase relative to malloc(M_ZERO) (not relative to the bzero that
    used to be there, but the code shrink might be more significant).  Plus
    there is no performance advantage over an optimized zeroing and 
    malloc(M_ZERO) being able to obtain a pre-zerod block.

						-Matt


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