Date: Thu, 29 Jul 1999 09:26:12 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: "Daniel C. Sobral" <dcs@newsguy.com> Cc: hackers@FreeBSD.ORG Subject: Re: MADV_SEQUENTIAL and GNU Grep Message-ID: <199907291626.JAA74429@apollo.backplane.com> References: <199907290439.XAA69977@celery.dragondata.com> <199907290445.VAA66252@apollo.backplane.com> <37A05F22.5AA2D27D@newsguy.com>
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:So it works, then? GNU grep has this #ifdef'ed out, with a comment
:about it impacting negatively on performance on BSD 4.1. I recall
:some rants on this subject a couple of years ago... If it is
:working, I'd like to change that 0 to 1 in our tree.
:
:--
:Daniel C. Sobral (8-DCS)
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.
-Matt
Matthew Dillon
<dillon@backplane.com>
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