From owner-cvs-all Fri Dec 14 0:37: 0 2001 Delivered-To: cvs-all@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id CEF3637B405; Fri, 14 Dec 2001 00:36:57 -0800 (PST) Received: (from dillon@localhost) by apollo.backplane.com (8.11.6/8.9.1) id fBE8asv22625; Fri, 14 Dec 2001 00:36:54 -0800 (PST) (envelope-from dillon) Date: Fri, 14 Dec 2001 00:36:54 -0800 (PST) From: Matthew Dillon Message-Id: <200112140836.fBE8asv22625@apollo.backplane.com> To: Søren Schmidt Cc: cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/sys/kern subr_disklabel.c References: <200112140828.fBE8SL376721@freebsd.dk> Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG :It seems Kirk McKusick wrote: :> mckusick 2001/12/13 21:50:44 PST :> :> Modified files: :> sys/kern subr_disklabel.c :> Log: :> Add disk I/O scheduling for positively niced processes. :> When a positively niced process requests a disk I/O, make :> it wait for its nice value of ticks before scheduling its :> I/O request if there are any other processes with I/O :> requests in the disk queue. For all the gory details, see :> the ``Running fsck in the Background'' paper in the Usenix :> BSDCon 2002 Conference Proceedings, pages 55-64. : :This breaks the kernel compile: : :../../../kern/subr_disklabel.c: In function `bioqdisksort': :.. This seems kind of incomplete in general, actually. What if you have several niced processes doing disk I/O? They'll trip over each other unnecessarily. What about background I/O? It won't be effected at all. What about directory operations? A niced process's blocked I/O could screw up performance for other processes. etc. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message