Re: build.sh: set creation is serialized

[Juan RP <xtraeme%gmail.com@localhost>]

On Wed, 30 Apr 2008 21:11:01 +0200
Alan Barrett <apb%netbsd.org@localhost> wrote:

> "Analyse and fix the problem" is the only solution that appeals to me.
> 
> On my system, the disk scheduler still seems to work very badly in the
> face of multiple consecutive tasks.  (One spindle, ffs on cgd on wd.)
> One task doing heavy disk I/O (rm -rf a large directory tree, cp -RPp a
> large tree, unpack a tarball with many files) causes other tasks that
> try to access the disk to experience very bad performance.  Multiple
> simultaneous disk-intensive tasks makes the system almost unusable for
> interactive work.

The default disk scheduler sucks with concurrent I/Os. BUFQ_READPRIO
or BUFQ_PRIOCSCAN will help you (in case that you aren't using them yet).

-- 
Juan Romero Pardines - xtraeme at gmail|netbsd dot org
        The NetBSD Project

Make your own NetBSD/x86 Live CD
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