From owner-freebsd-hackers Thu Jul 29 7:24:35 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from peach.ocn.ne.jp (peach.ocn.ne.jp [210.145.254.87]) by hub.freebsd.org (Postfix) with ESMTP id C7F7A155C0 for ; Thu, 29 Jul 1999 07:24:33 -0700 (PDT) (envelope-from dcs@newsguy.com) Received: from newsguy.com by peach.ocn.ne.jp (8.9.1a/OCN) id XAA14680; Thu, 29 Jul 1999 23:23:40 +0900 (JST) Message-ID: <37A05F22.5AA2D27D@newsguy.com> Date: Thu, 29 Jul 1999 23:03:14 +0900 From: "Daniel C. Sobral" X-Mailer: Mozilla 4.6 [en] (Win98; I) X-Accept-Language: en,pt-BR,ja MIME-Version: 1.0 To: Matthew Dillon Cc: hackers@FreeBSD.ORG Subject: MADV_SEQUENTIAL and GNU Grep References: <199907290439.XAA69977@celery.dragondata.com> <199907290445.VAA66252@apollo.backplane.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Matthew Dillon wrote: > > MADV_SEQUENTIAL *WILL* work. It changes the page fault > read-behind/read-ahead. Normally the VM system reads behind a bit as well > as reads ahead. If you set MADV_SEQUENTIAL it shifts to just doing > read-ahead, and it does more of it. 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) 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." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message