Re: [PATCH net-next] arch_fast_hash: avoid indirect function calls and implement hash in asm
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: 2014-12-04 15:56:47
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On Thu, Dec 04, 2014 at 02:08:50PM +0100, Hannes Frederic Sowa wrote:
By default the arch_fast_hash hashing function pointers are initialized to jhash(2). If during boot-up a CPU with SSE4.2 is detected they get updated to the CRC32 ones. This dispatching scheme incurs a function pointer lookup and indirect call for every hashing operation.
Just curious, is jhash actually faster than generic C CRC32 on common platforms? Cheers, -- Email: Herbert Xu [off-list ref] Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt