Date: Wed, 23 Nov 2005 19:08:24 -0500 From: Kris Kennaway <kris@obsecurity.org> To: David Xu <davidxu@freebsd.org> Cc: current@FreeBSD.org, Kris Kennaway <kris@obsecurity.org> Subject: Re: 4BSD process starvation during I/O Message-ID: <20051124000824.GA11032@xor.obsecurity.org> In-Reply-To: <438500BE.3020507@freebsd.org> References: <20051123201837.GA4822@xor.obsecurity.org> <438500BE.3020507@freebsd.org>
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--OXfL5xGRrasGEqWY Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Nov 24, 2005 at 07:52:30AM +0800, David Xu wrote: > Kris Kennaway wrote: >=20 > >Perhaps this can be tweaked. > > > >Kris > > > >P.S. Please, no responses about how maybe someone could write a new > >scheduler that doesn't have this property. > > > > > >=20 > > > Can you try it again with FULL_PREEMPTION is turned on ? Didn't really make a difference: # sh dd.sh 1 mdconfig: ioctl(/dev/mdctl): No such file or directory md0 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.325922 secs (202451919 bytes/sec) # sh dd.sh 2 md0 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.828649 secs (146794428 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.828715 secs (146789108 bytes/sec) # sh dd.sh 3 md0 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.875729 secs (143109929 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.879152 secs (142849247 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.883898 secs (142489377 bytes/sec) # sh dd.sh 4 md0 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.834240 secs (146346968 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.858093 secs (144468255 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.894780 secs (141671047 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 3.108751 secs (86348335 bytes/sec) # sh dd.sh 12 md0 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.860367 secs (144291681 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.885677 secs (142354961 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 1.983243 secs (135351757 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 3.409261 secs (78737139 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 3.762066 secs (71353204 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 3.910402 secs (68646510 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 5.086984 secs (52769079 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 5.566311 secs (48225018 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 5.816347 secs (46151897 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 6.818567 secs (39368309 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 7.375191 secs (36397085 bytes/sec) 16384+0 records in 16384+0 records out 268435456 bytes transferred in 7.568077 secs (35469440 bytes/sec) # --OXfL5xGRrasGEqWY Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQFDhQR3Wry0BWjoQKURAigDAJ951FvCLW4lhhL5laz//H5GaIkf6QCg0Daf 7rtmBRUfV9A8EIIAJrm4GsQ= =0Wlz -----END PGP SIGNATURE----- --OXfL5xGRrasGEqWY--
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