Date: Thu, 31 Dec 2015 13:50:57 -0500 From: Allan Jude <allanjude@freebsd.org> To: "Jonathan T. Looney" <jtl@freebsd.org>, Bruce Evans <brde@optusnet.com.au> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r292955 - head/lib/libmd Message-ID: <56857911.5010205@freebsd.org> In-Reply-To: <D2AADE36.4E8D4%jlooney@juniper.net> References: <201512301804.tBUI4oGp065466@repo.freebsd.org> <20151231115651.R995@besplex.bde.org> <20151231143314.Y1520@besplex.bde.org> <5684D606.3080609@freebsd.org> <D2AADE36.4E8D4%jlooney@juniper.net>
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This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --O083ff9QVAvbmPH4aqR4UNC1wvdF6BD95 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 2015-12-31 13:32, Jonathan T. Looney wrote: > On 12/31/15, 2:15 AM, "Allan Jude" <allanjude@freebsd.org> wrote: >=20 >> It seems these problems also slow things down, a lot: >> >> # time md5 /media/md5test/bigdata >> MD5 (/media/md5test/bigdata) =3D 6afad0bf5d8318093e943229be05be67 >> 4.310u 3.476s 0:07.79 99.8% 20+167k 0+0io 0pf+0w >> # time env LD_PRELOAD=3D/usr/obj/media/svn/md5/head/tmp/lib/libmd.so >> /usr/obj/media/svn/md5/head/sbin/md5/md5 /media/md5test/bigdata >> MD5 (/media/md5test/bigdata) =3D 6afad0bf5d8318093e943229be05be67 >> 4.133u 0.354s 0:04.49 99.7% 20+167k 1+0io 0pf+0w >> >> (file is fully cached in ZFS ARC, dd reads it at 11GB/s) >> >> Will investigate more tomorrow. >=20 > md5 will be slower than dd due to the extra processing it needs to do t= o > generate the hash. I suspect that explains the difference you're seeing= > between those utilities. >=20 > Jonathan >=20 >=20 >=20 Sorry, you missed my point here. I replaced MDXFile() with the implementation included in my earlier email. Using the newer libmd with that code, cut the time to md5 the SAME data down a lot. I need to do a more scientific test on a box that isn't doing other stuff still though. The comment about dd doing 11GB/s, was just to clarify that I wasn't reading the file from disk, which would introduce other variables. --=20 Allan Jude --O083ff9QVAvbmPH4aqR4UNC1wvdF6BD95 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (MingW32) iQIcBAEBAgAGBQJWhXkVAAoJEBmVNT4SmAt+ILUQAIqfQHl2vbev0r4P50O25avg c4M8u2z+rWZ0ETMKwT1ND5vAA+tCnJ8qC816Pk/RvuJSCBUYTXTRysV00WWGBlyP DcJ43uvOjdRDu8xjOQ7FTsR3F3jXE1Sbf6g8MRO6ZkuPXPrEhFj2ejSBWIIQ2UE6 1KhkMbGUHeRWWiyHA4epCCwiVm9v0jB8Njf7ruZFQeT6OBYEWNqq1RCpwRrsey1b UGUczXjIa530YLZjBIAw1en/Kkm2JrPG9iY3QosVqbmp+jEsKSSqk7CPeKpV+uy0 vmAThXR2p7rb7YRjn/YRw7wDi5ynqaSpzYGQ1AvO+aTU2gE87dTQJdhLzjdEujPs NzgWsT5aZHrlLrXpFuE4rCrmE2yfrpJAOeXdVz6q3Eh3spQXxTNZnD+peM1vA/DC yoNx2mm8Sa/vCvUP2/0nEHJwKzzP02fwXB6RzaXhUfXJzGrMDGSxnSOXW+SYLWU4 oZnC3/2/4wLnJRFuoB0D3M0kyei+JMBF0ZFNY12FDuyZGOQg818PPRlcLR9YdUIm v74O1Am8H42NXCjWreZlWGXXmfK22zixF92K2dk2ySVj+PmbljBjXKzX1M/qzkPL KHeQZiW24C5AUWoiilWEmHZBa9SbxdyyMCesLxVBEM0uySbJUeXyONkR/m6pmjNU q5jvRUJq8CyWeX02BZY+ =89t7 -----END PGP SIGNATURE----- --O083ff9QVAvbmPH4aqR4UNC1wvdF6BD95--
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