From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:17445 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750951AbaEGUun (ORCPT ); Wed, 7 May 2014 16:50:43 -0400 Date: Wed, 7 May 2014 13:50:35 -0700 From: "Darrick J. Wong" To: Tomasz Torcz , linux-btrfs@vger.kernel.org Cc: Liu Bo Subject: Re: [RFC PATCH 0/3] Btrfs: add xxhash algorithm Message-ID: <20140507205035.GA8921@birch.djwong.org> References: <1399460193-1713-1-git-send-email-bo.li.liu@oracle.com> <20140507110806.GD26824@mother.pipebreaker.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20140507110806.GD26824@mother.pipebreaker.pl> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Wed, May 07, 2014 at 01:08:06PM +0200, Tomasz Torcz wrote: > On Wed, May 07, 2014 at 06:56:29PM +0800, Liu Bo wrote: > > "xxHash is an extremely fast non-cryptographic Hash algorithm, working at speeds > > close to RAM limits."[1] And xxhash is 32-bits hash, same as crc32. > > > > Here is the hash comparsion extracted from the link[1]: > > (single thread, Windows Seven 32 bits, using Open Source's SMHasher on a Core 2 > > Duo @3GHz) > > > > -------------------------------------------- > > Name Speed Q.Score Author > > xxHash 5.4 GB/s 10 > > CRC32 0.43 GB/s 9 > > -------------------------------------------- > > Core 2 Duo is awfully old CPU. Since 2008, Intel CPUs have crc32 instruction, > hugely speeding up CRC operations. Just for kicks I (sloppily) benchmarked a few of the kernel's hash implementations on a Core i5-3320M CPU @3.3GHz: xxhash: 6.0GB/s crc32c-intel: 11.5GB/s crc32c (no hw accel): 1.8GB/s --D > > > -- > Tomasz Torcz "God, root, what's the difference?" > xmpp: zdzichubg@chrome.pl "God is more forgiving." > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html