To: Joe Buck <Joe.Buck@synopsys.COM>
Cc: Andi Kleen <ak@suse.de>,
       Ulrich Weigand <weigand@i1.informatik.uni-erlangen.de>, gcc@gcc.gnu.org,
       linux-kernel@vger.kernel.org, schwidefsky@de.ibm.com
Subject: Re: Linux 2.6 nanosecond time stamp weirdness breaks GCC build
In-Reply-To: <20040401143908.B4619@synopsys.com> (Joe Buck's message of
 "Thu, 1 Apr 2004 14:39:08 -0800")
References: <200404011928.VAA23657@faui1d.informatik.uni-erlangen.de>
	<20040401220957.5f4f9ad2.ak@suse.de>
	<20040401203923.GA32177@nevyn.them.org>
	<20040401143908.B4619@synopsys.com>
From: prj@po.cwru.edu (Paul Jarc)
Organization: What did you have in mind?  A short, blunt, human pyramid?
Mail-Copies-To: nobody
Mail-Followup-To: Joe Buck <Joe.Buck@synopsys.COM>, Andi Kleen <ak@suse.de>,
 Ulrich Weigand <weigand@i1.informatik.uni-erlangen.de>, gcc@gcc.gnu.org, 
 linux-kernel@vger.kernel.org, schwidefsky@de.ibm.com
Date: Thu, 01 Apr 2004 17:44:59 -0500
Message-ID: <m3ad1vjp1a.fsf@multivac.cwru.edu>
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Joe Buck <Joe.Buck@synopsys.COM> wrote:
> Case 2: make falsely thinks that the .c is younger than the .o.  It
> recompiles the .c file, even though it didn't have to.  Harmless.

The OP explained how this can be harmful in the case of parallel
builds - the .o file is not updated atomically, so while one part of
the build is (unnecessarily) updating it, another part will fail to
find it.


paul
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