From: Anton Blanchard <anton@samba.org>
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: paulus@samba.org, linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 1/3] powerpc: Optimise 64bit csum_partial
Date: Wed, 4 Aug 2010 09:11:14 +1000 [thread overview]
Message-ID: <20100803231114.GP29316@kryten> (raw)
In-Reply-To: <1C2B156C-E6C9-47CC-B5BF-6AA603581EC3@kernel.crashing.org>
Hi Segher,
> Not really. Do you know how many 16/32-bit words you can add before a
> 64-bit register can overflow? :-)
Thats a very good point. I thought about using 32bit adds when writing
the copy and checksum routine, but came to the conclusion that it wouldn't go
any faster than one using addes. The checksum only routine was the same loop
without the stores.
We rarely use csum_partial now we have copy and checksum to and from user
now, but I'll take a look at speeding it up in a follow on patch. Thanks!
Anton
next prev parent reply other threads:[~2010-08-03 23:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-03 6:08 [PATCH 1/3] powerpc: Optimise 64bit csum_partial Anton Blanchard
2010-08-03 6:09 ` [PATCH 2/3] powerpc: Optimise 64bit csum_partial_copy_generic and add csum_and_copy_from_user Anton Blanchard
2010-08-03 6:11 ` [PATCH 3/3] powerpc: Add 64bit csum_and_copy_to_user Anton Blanchard
2010-08-03 15:09 ` [PATCH 1/3] powerpc: Optimise 64bit csum_partial Segher Boessenkool
2010-08-03 23:11 ` Anton Blanchard [this message]
2010-08-03 23:39 ` Segher Boessenkool
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