Re: [PATCH v2 29/35] powerpc/perf: remove current_is_64bit()

From: "Michal Suchánek" <msuchanek@suse.de>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: linuxppc-dev@lists.ozlabs.org,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
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Subject: Re: [PATCH v2 29/35] powerpc/perf: remove current_is_64bit()
Date: Wed, 27 Nov 2019 10:49:00 +0100	[thread overview]
Message-ID: <20191127094900.GA11661@kitsune.suse.cz> (raw)
In-Reply-To: <ecceebf5-391a-c75d-28a7-44623adc06e8@c-s.fr>

On Wed, Nov 27, 2019 at 06:41:09AM +0100, Christophe Leroy wrote:
> 
> 
> Le 26/11/2019 à 21:13, Michal Suchanek a écrit :
> > Since commit ed1cd6deb013 ("powerpc: Activate CONFIG_THREAD_INFO_IN_TASK")
> > current_is_64bit() is quivalent to !is_32bit_task().
> > Remove the redundant function.
> > 
> > Link: https://github.com/linuxppc/issues/issues/275
> > Link: https://lkml.org/lkml/2019/9/12/540
> > 
> > Fixes: linuxppc#275
> > Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
> > Signed-off-by: Michal Suchanek <msuchanek@suse.de>
> 
> This change is already in powerpc/next, see https://github.com/linuxppc/linux/commit/42484d2c0f82b666292faf6668c77b49a3a04bc0

Right, needs rebase.

Thanks

Michal
> 
> Christophe
> 
> > ---
> >   arch/powerpc/perf/callchain.c | 17 +----------------
> >   1 file changed, 1 insertion(+), 16 deletions(-)
> > 
> > diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
> > index c84bbd4298a0..35d542515faf 100644
> > --- a/arch/powerpc/perf/callchain.c
> > +++ b/arch/powerpc/perf/callchain.c
> > @@ -284,16 +284,6 @@ static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry,
> >   	}
> >   }
> > -static inline int current_is_64bit(void)
> > -{
> > -	/*
> > -	 * We can't use test_thread_flag() here because we may be on an
> > -	 * interrupt stack, and the thread flags don't get copied over
> > -	 * from the thread_info on the main stack to the interrupt stack.
> > -	 */
> > -	return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
> > -}
> > -
> >   #else  /* CONFIG_PPC64 */
> >   /*
> >    * On 32-bit we just access the address and let hash_page create a
> > @@ -321,11 +311,6 @@ static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry
> >   {
> >   }
> > -static inline int current_is_64bit(void)
> > -{
> > -	return 0;
> > -}
> > -
> >   static inline int valid_user_sp(unsigned long sp, int is_64)
> >   {
> >   	if (!sp || (sp & 7) || sp > TASK_SIZE - 32)
> > @@ -486,7 +471,7 @@ static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry,
> >   void
> >   perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
> >   {
> > -	if (current_is_64bit())
> > +	if (!is_32bit_task())
> >   		perf_callchain_user_64(entry, regs);
> >   	else
> >   		perf_callchain_user_32(entry, regs);
> > 