On Tue, 29 Jul 2008 23:07:45 +1000 Simon Horman <horms@xxxxxxxxxxxx> wrote:
> On Tue, Jul 29, 2008 at 10:47:09PM +1000, Keith Owens wrote:
> > Simon Horman (on Tue, 29 Jul 2008 19:47:20 +1000) wrote:
> > >Aesthetic issues aside is it safe to call up() if down_trylock() failed?
> > >
> > >arch/ia64/kernel/salinfo.c: In function `salinfo_work_to_do':
> > >arch/ia64/kernel/salinfo.c:195: warning: ignoring return value of `down_trylock'
> > >
> > >Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>
> > >
> > >Index: linux-2.6/arch/ia64/kernel/salinfo.c
> > >===================================================================
> > >--- linux-2.6.orig/arch/ia64/kernel/salinfo.c 2008-07-29 19:06:33.000000000 +1000
> > >+++ linux-2.6/arch/ia64/kernel/salinfo.c 2008-07-29 19:40:02.000000000 +1000
> > >@@ -192,8 +192,8 @@ struct salinfo_platform_oemdata_parms {
> > > static void
> > > salinfo_work_to_do(struct salinfo_data *data)
> > > {
> > >- down_trylock(&data->mutex);
> > >- up(&data->mutex);
> > >+ if (down_trylock(&data->mutex) == 0)
> > >+ up(&data->mutex);
> > > }
> > >
> > > static void
> >
> > NAK. The whole point of this function is to set the mutex to the up
> > state, irrespective of whether it was already down or not. Tracking
> > the state of data->mutex in all the possible contexts is just too
> > fragile, especially since it can be modified from NMI context.
> > salinfo_work_to_do() ensures that the mtuex ends in the up state.
boggle. I daren't look.
> > To remove the warning, just stick '(void)' in front of down_trylock().
>
> Thanks, will do.
>
For gawd's sake add a comment there too.
--
To unsubscribe from this list: send the line "unsubscribe linux-ia64" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|