From owner-freebsd-hackers  Thu Jul 29  9:51:49 1999
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Date: Fri, 30 Jul 1999 01:50:28 +0900
From: "Daniel C. Sobral" <dcs@newsguy.com>
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To: Matthew Dillon <dillon@apollo.backplane.com>
Cc: hackers@FreeBSD.ORG
Subject: Re: MADV_SEQUENTIAL and GNU Grep
References: <199907290439.XAA69977@celery.dragondata.com> <199907290445.VAA66252@apollo.backplane.com> <37A05F22.5AA2D27D@newsguy.com> <199907291626.JAA74429@apollo.backplane.com>
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Matthew Dillon wrote:
> 
>     Yes, it will work.  Oops.  I do see one problem though... if you do
>     this the underlying file object will be marked for sequential operation
>     even after the grep (in this case) exits.  That is, an madvise() of
>     MADV_NORMAL, SEQUENTIAL, or RANDOM appears to have a permanent effect
>     on the object.  This is probably not correct behavior.  We could probably
>     fix this by moving this particular flag from the object to the vm_entry.

....

Could you please elaborate on "permanent"? To what structure the
information is currently attached, and what, if anything, can make
that structure "go away", short of a reboot?

Of course, we could MADV_NORMAL afterwards, though that would
require changing more than one character. I'm not sure I'm ready for
so much coding... :-)

--
Daniel C. Sobral			(8-DCS)
dcs@newsguy.com
dcs@freebsd.org

	"Is it true that you're a millionaire's son who never worked a day
in your life?"
	"Yeah, I guess so."
	"Lemme tell you, son, you ain't missed a thing."


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