Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 27 Jan 2006 16:42:03 -0500
From:      John Baldwin <jhb@freebsd.org>
To:        Jason Evans <jasone@freebsd.org>
Cc:        cvs-src@freebsd.org, src-committers@freebsd.org, Andrey Chernov <ache@freebsd.org>, cvs-all@freebsd.org
Subject:   Re: cvs commit: src/lib/libc/stdlib malloc.c
Message-ID:  <200601271642.06181.jhb@freebsd.org>
In-Reply-To: <6B47D688-0A7D-421F-9830-9493EC375307@FreeBSD.ORG>
References:  <200601270236.k0R2ai2x067283@repoman.freebsd.org> <20060127025150.GA57825@nagual.pp.ru> <6B47D688-0A7D-421F-9830-9493EC375307@FreeBSD.ORG>

next in thread | previous in thread | raw e-mail | index | archive | help
On Thursday 26 January 2006 22:02, Jason Evans wrote:
> On Jan 26, 2006, at 6:51 PM, Andrey Chernov wrote:
> > I worry about my system performance. Could you please make all
> > statistics
> > and debug code conditional, debending on some flags which could be
> > set as
> > malloc options? Even in case this is a test period now, some people
> > perhaps don't want some tests. It is much easy to turn some tests
> > off via
> > malloc options than to comment out manually corresponding malloc.c
> > defines
> > after each cvsup.
>
> Unfortunately, run-time checks for the debugging features are
> expensive, since the debugging code is scattered throughout
> malloc.c.  This pretty much mandates compile-time configuration, for
> performance reasons.
>
> I can disable statistics and debugging, if there's a general
> consensus to do so.  How much performance difference is the debug/
> stats code making for you?  I've only been disabling debug/stats for
> benchmarking purposes, so I don't have a good feel for how much it
> impacts overall system performance.

Perhaps you could add some Makefile foo so Andrey can just add some entries to 
his /etc/make.conf (like NO_MALLOC_DEBUG, NO_MALLOC_STATS).  This would give 
Andrey what he needs w/o adding runtime overhead and w/o requiring Andrey to 
hack the source each time.

-- 
John Baldwin <jhb@FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200601271642.06181.jhb>