[PATCH] remove unnecessary cache flush on v6 copypage

[PATCH] remove unnecessary cache flush on v6 copypage

[heechul Yun]

ARM: mm: remove unnecessary cache flush on v6 copypage

Signed-off-by: Heechul Yun <heechul@illinois.edu>
--
arch/arm/mm/copypage-v6.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
index bdba6c6..63cca00 100644
--- a/arch/arm/mm/copypage-v6.c
+++ b/arch/arm/mm/copypage-v6.c
@@ -41,7 +41,6 @@ static void v6_copy_user_highpage_nonaliasing(struct page *to,
       kfrom = kmap_atomic(from, KM_USER0);
       kto = kmap_atomic(to, KM_USER1);
       copy_page(kto, kfrom);
-       __cpuc_flush_dcache_area(kto, PAGE_SIZE);
       kunmap_atomic(kto, KM_USER1);
       kunmap_atomic(kfrom, KM_USER0);
 }

--

Heechul

[PATCH] remove unnecessary cache flush on v6 copypage

[Russell King - ARM Linux]

On Wed, Jul 06, 2011 at 07:19:59PM -0700, heechul Yun wrote:
> ARM: mm: remove unnecessary cache flush on v6 copypage
> 
> Signed-off-by: Heechul Yun <heechul@illinois.edu>
> --
> arch/arm/mm/copypage-v6.c |    1 -
>  1 files changed, 0 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
> index bdba6c6..63cca00 100644
> --- a/arch/arm/mm/copypage-v6.c
> +++ b/arch/arm/mm/copypage-v6.c
> @@ -41,7 +41,6 @@ static void v6_copy_user_highpage_nonaliasing(struct page *to,
>        kfrom = kmap_atomic(from, KM_USER0);
>        kto = kmap_atomic(to, KM_USER1);
>        copy_page(kto, kfrom);
> -       __cpuc_flush_dcache_area(kto, PAGE_SIZE);
>        kunmap_atomic(kto, KM_USER1);
>        kunmap_atomic(kfrom, KM_USER0);
>  }

Patch looks good, except that it's whitespace damaged (the tabs are
replaced by spaces) which makes it hard to apply.  Could you try to
sort that out.  Documentation/email-clients.txt in the kernel tree
may help with that.

I assume Catalin will (eventually) provide an ack - and at that point
please submit it (in non-whitespace damaged form) to the patch system,
thanks.

[PATCH] remove unnecessary cache flush on v6 copypage

[Catalin Marinas]

On Thursday, July 7, 2011, heechul Yun <heechul@illinois.edu> wrote:
> ARM: mm: remove unnecessary cache flush on v6 copypage
>
> Signed-off-by: Heechul Yun <heechul@illinois.edu>

I would clarify the commit log a bit stating that this flush is no
longer necessary because of commit c0177800. We had a good reason for
adding the flush initially.

Otherwise,

Acked-by: Catalin Marinas <catalin.marinas@arm.com>


-- 
Catalin

[PATCH] remove unnecessary cache flush on v6 copypage

[saeed bishara]

On Thu, Jul 7, 2011 at 12:02 PM, Catalin Marinas
<catalin.marinas@arm.com> wrote:
> On Thursday, July 7, 2011, heechul Yun <heechul@illinois.edu> wrote:
>> ARM: mm: remove unnecessary cache flush on v6 copypage
I think you better mention that this is regarding v6 nonaliasing mode.
>>
>> Signed-off-by: Heechul Yun <heechul@illinois.edu>
>
> I would clarify the commit log a bit stating that this flush is no
> longer necessary because of commit c0177800. We had a good reason for
> adding the flush initially.
I agree, but I would also mention that the flush was needed in order
to coherent between dcache and icache, and now this is being handled
by __sync_icache_dcache
saeed