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Date: Mon, 14 May 2007 16:12:24 -0400
From: Kris Kennaway <kris@obsecurity.org>
To: Jason Evans <jasone@freebsd.org>
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Cc: Robert Watson <rwatson@FreeBSD.org>, freebsd-arch@freebsd.org
Subject: Re: Multiple malloc(3)s (was Re: HEADS DOWN)
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On Mon, May 14, 2007 at 12:19:54PM -0700, Jason Evans wrote:
> Robert Watson wrote:
> >I have to admit, 
> >however, that I do wish we'd retained an easy switch to let us go back 
> >and forth between phkmalloc and jemalloc for comparison purposes.
> 
> It is pretty easy to go back and forth for comparison purposes, because 
> revision 1.92 of src/lib/libc/stdlib/malloc.c is a source-compatible 
> version of phkmalloc.  You can update just that one file and get a libc 
> with phkmalloc instead of jemalloc.  I continue to make use of this for 
> performance testing purposes, and it remains a sound strategy for 
> diagnosing possible regressions.

I can confirm how trivial this is to do - it is indeed only one file
that needs to be reverted, and you can even install it as a separate
libc (e.g. in /tmp) and use LD_LIBRARY_PATH, libmap.conf, etc to
direct access to it on a per-application basis.

Kris