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Date: Tue, 9 Mar 2010 18:21:19 +0100 (CET)
From: Julia Lawall <julia@diku.dk>
To: Christophe Jaillet <christophe.jaillet@wanadoo.fr>
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [patch] arch/powerpc/platforms/pseries/ras.c - cleanup
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On Tue, 9 Mar 2010, Christophe Jaillet wrote:

> I personaly think that yes, because the smaller, the better.

Perhaps the memset solves some concurrency problem?  I just wonder why 
such a pattern would come up more than one time, in code that looks fairly 
diverse (ie not copy-paste), if it really has no purpose.  But I can 
always send something and see what happens...

julia

> Could you write one of your semantic match and send the patches ?
> 
> CJ
> 
> "Julia Lawall" <julia@diku.dk> a écrit dans le message de
> news:Pine.LNX.4.64.1003082235030.5727@ask.diku.dk...
> > On Mon, 8 Mar 2010, Christophe Jaillet wrote:
> >
> > > From: Christophe Jaillet <christophe.jaillet@wanadoo.fr>
> > >
> > > Hi, here is a patch against arch/powerpc/platforms/pseries/ras.c.
> > >
> > > No need to memset (.., 0, ...) a buffer that is complety filled by a
> memcpy
> > > the line after.
> >
> > I find 14 occurrences of this in linux-next.  Could it be useful for
> > something?
> >
> > julia
> >
> >
> > >
> > >
> > > Signed-off-by: Christophe Jaillet <christophe.jaillet@wanadoo.fr>
> > >
> > > ---
> > >
> > > diff --git a/arch/powerpc/platforms/pseries/ras.c
> > > b/arch/powerpc/platforms/pseries/ras.c
> > > index 2b548af..7a401ed 100644
> > > --- a/arch/powerpc/platforms/pseries/ras.c
> > > +++ b/arch/powerpc/platforms/pseries/ras.c
> > > @@ -276,7 +276,6 @@ static struct rtas_error_log
> *fwnmi_get_errinfo(struct
> > > pt_regs *regs)
> > >       (errdata >= rtas.base && errdata < rtas.base + rtas.size - 16)) {
> > >    savep = __va(errdata);
> > >    regs->gpr[3] = savep[0]; /* restore original r3 */
> > > -  memset(mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
> > >    memcpy(mce_data_buf, (char *)(savep + 1), RTAS_ERROR_LOG_MAX);
> > >    errhdr = (struct rtas_error_log *)mce_data_buf;
> > >   } else {
> > >
> > >
> > >
> > > --
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> 
> 
> 
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