From mboxrd@z Thu Jan 1 00:00:00 1970 From: Harald Hoyer Date: Tue, 25 May 2004 10:58:36 +0000 Subject: Re: Update on disk IO slowdown using udev Message-Id: <40B326DC.4060707@redhat.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="------------enig1E3A51B6F3E8376C2374BD83" List-Id: References: <20040525104659.GF26696@y-boda.hpc2n.umu.se> In-Reply-To: <20040525104659.GF26696@y-boda.hpc2n.umu.se> To: linux-hotplug@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig1E3A51B6F3E8376C2374BD83 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Try it the other way round. I guess the data is cached :) Use bonnie or hdparm -Tt to measure throughput! Ake wrote: > Hi! > After some more experimenting i did the following, > > mkdir /tmpfsdev > mount -t tmpfs tmpfs /tmpfsdev > mknod /tmpfsdev/sdb b 8 16 (This is my test disk) > dd if=/tmpfsdev/sdb of=/dev/null bs=8192k count=20 > 20+0 records in > 20+0 records out > 167772160 bytes transferred in 11.006714 seconds (15242711 bytes/sec) > > mkdir /rawdev > mknod /rawdev/sdb b 8 16 > dd if=/rawdev/sdb of=/dev/null bs=8192k count=20 > 20+0 records in > 20+0 records out > 167772160 bytes transferred in 1.668631 seconds (100544793 bytes/sec) > > > So tmpfs is the culprit. > So, yes using udev i DO get a slowdown due to its use of tmpfs. > --------------enig1E3A51B6F3E8376C2374BD83 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFAsybft7dFwsVXVUIRAicMAKCcbfXFVL/T/coB7uVCF9YaYaVUdwCgtdo8 AGygHoX+n1C5VtMNgMatNDc= =Iy/O -----END PGP SIGNATURE----- --------------enig1E3A51B6F3E8376C2374BD83-- ------------------------------------------------------- This SF.Net email is sponsored by: Oracle 10g Get certified on the hottest thing ever to hit the market... Oracle 10g. Take an Oracle 10g class now, and we'll give you the exam FREE. http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel