Re: [patch] arch/powerpc/platforms/pseries/ras.c - cleanup

Re: [patch] arch/powerpc/platforms/pseries/ras.c - cleanup

[Julia Lawall]

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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Re: [patch] arch/powerpc/platforms/pseries/ras.c - cleanup

[Christophe Jaillet]

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

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 {
> >
> >
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe
kernel-janitors" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >

Re: [patch] arch/powerpc/platforms/pseries/ras.c - cleanup

[Julia Lawall]

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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 {
> > >
> > >
> > >
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe
> kernel-janitors" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > >
> 
> 
> 
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