From owner-freebsd-hackers Fri Dec 4 06:57:59 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id GAA09004 for freebsd-hackers-outgoing; Fri, 4 Dec 1998 06:57:59 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id GAA08998 for ; Fri, 4 Dec 1998 06:57:52 -0800 (PST) (envelope-from luigi@labinfo.iet.unipi.it) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id NAA08298; Fri, 4 Dec 1998 13:48:36 +0100 From: Luigi Rizzo Message-Id: <199812041248.NAA08298@labinfo.iet.unipi.it> Subject: Re: Nonblocking page fetching To: toasty@home.dragondata.com (Kevin Day) Date: Fri, 4 Dec 1998 13:48:36 +0100 (MET) Cc: hackers@FreeBSD.ORG In-Reply-To: <199812041431.IAA27124@home.dragondata.com> from "Kevin Day" at Dec 4, 98 08:31:20 am X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > I have an application where I'm streaming large amounts of data from disk, ... > The hack I ended up using was another process that I could tell that I > needed the frames, and all it did was sit in a for loop touching every page, > to force them to be brought in. > > This has some obvious disadvantages, but it stopped my movie player from > sitting in vmwait when it could be doing other things. is it so bad ? The forked process should consume very little memory and because they are local you can even resort to or some cheap local IPC mechanism to synchronize them. From a portability point of view i think this is going to be to be better than provide a specialised syscall. > One final note... Does anyone know what effect turning off the bzero on new > pages would be? Security is not an issue in this system, as it's not again how bad is it ? bzero is generally done in the idle loop if i am not mistaken so you should not be affected too badly by that unless you are at or near 100% CPU usage. cheers luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message