Date: Sat, 4 Sep 2004 10:23:44 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: Don Lewis <truckman@FreeBSD.org> Cc: freebsd-current@FreeBSD.org Subject: Re: what is fsck's "slowdown"? Message-ID: <200409041723.i84HNi4Q046252@apollo.backplane.com> References: <200409040709.i8479U79031043@gw.catspoiler.org>
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:This sort of thing was my initial thought, but the posted CPU usage
:statistics show that fsck is burning up most of its CPU cycles in
:userland.
:
:>> load: 0.99 cmd: fsck 67 [running] 15192.26u 142.30s 99% 184284k
:
:Increasing MAXBUFSPACE looks like it would make the problem worse
:because getdatablk() does a linear search.
Oh my. I didn't even notice. That code dates all the way back to 1994
so I wont bash the author too badly, but it is pretty aweful coding.
Hashing the buffer cache is trivial. I'll do it for DragonFly and post
the patch as a template for you guys to do it in FreeBSD (or you could just
do it on your own, it really does look trivial).
-Matt
Matthew Dillon
<dillon@backplane.com>
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