Subject: Re: [PATCH 19/31] powerpc/mm: Convert 4k hash insert to C

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Mon, 21 Sep 2015 14:27:58 +0530

Benjamin Herrenschmidt <[email-masked]> writes:

> On Mon, 2015-09-21 at 12:10 +0530, Aneesh Kumar K.V wrote:
>> Signed-off-by: Aneesh Kumar K.V <[email-masked]>
>> ---
>>  arch/powerpc/mm/Makefile        |   3 +
>>  arch/powerpc/mm/hash64_64k.c    | 204 +++++++++++++++++++++
>>  arch/powerpc/mm/hash_low_64.S   | 380 ------------------------------
>> ----------
>>  arch/powerpc/mm/hash_utils_64.c |   4 +-
>>  4 files changed, 210 insertions(+), 381 deletions(-)
>>  create mode 100644 arch/powerpc/mm/hash64_64k.c
>
> Did you check if there was any measurable performance difference ?
>

Not with this patch series. I did look at the .s file generated between
__hash_page_4k and hash64_4k.c and found them similar. 

I will also try some micro benchmarks w.r.t hash insert/update and will
update later with numbers.

-aneesh