From owner-freebsd-current Sat Jul 25 18:42:14 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id SAA23755 for freebsd-current-outgoing; Sat, 25 Jul 1998 18:42:14 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from Kitten.mcs.com (Kitten.mcs.com [192.160.127.90]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id SAA23747 for ; Sat, 25 Jul 1998 18:42:08 -0700 (PDT) (envelope-from karl@Mars.mcs.net) Received: from Mars.mcs.net (karl@Mars.mcs.net [192.160.127.85]) by Kitten.mcs.com (8.8.7/8.8.2) with ESMTP id UAA08316; Sat, 25 Jul 1998 20:41:41 -0500 (CDT) Received: (from karl@localhost) by Mars.mcs.net (8.8.7/8.8.2) id UAA05246; Sat, 25 Jul 1998 20:41:41 -0500 (CDT) Message-ID: <19980725204141.39635@mcs.net> Date: Sat, 25 Jul 1998 20:41:41 -0500 From: Karl Denninger To: Brian Feldman Cc: IBS / Andre Oppermann , current@FreeBSD.ORG Subject: Re: MMAP problems References: <35BA4F9A.3E28B29E@pipeline.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.84 In-Reply-To: ; from Brian Feldman on Sat, Jul 25, 1998 at 06:20:19PM -0400 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sat, Jul 25, 1998 at 06:20:19PM -0400, Brian Feldman wrote: > Hmm, what is the default behavior of msync()? Is it handled automatically, > say, in-kernel? If so, maybe it needs to be explicitly called; also is > this daemon using a drive with async/softupdates by any chance? > > Cheers, > Brian Feldman > green@unixhelp.org Its not using a drive which is mounted async or with softupdates. Msync is *NOT* called anywhere in the code that I can find. However, this code is reported to work on a lot of other platforms/systems, and on *SOME* versions of FreeBSD without trouble. It is definitely broken on -current, although not "badly"; the problem happens infrequently, but often enough to piss me off. The real problem is that I don't know what the bad sequence of calls is, and therefore, I have to consider mmap() and friends (including the SYSVSHM implementation, which uses it) unusable. This is a *bad* thing over all, and something that the FreeBSD folks really need to consider doing something about - not having usable and reliable mmap/SHM capability basically destroys FreeBSD as a DBMS or news server if you care about minor things like data integrity. -- -- Karl Denninger (karl@MCS.Net)| MCSNet - Serving Chicagoland and Wisconsin http://www.mcs.net/ | T1's from $600 monthly / All Lines K56Flex/DOV | NEW! Corporate ISDN Prices dropped by up to 50%! Voice: [+1 312 803-MCS1 x219]| EXCLUSIVE NEW FEATURE ON ALL PERSONAL ACCOUNTS Fax: [+1 312 803-4929] | *SPAMBLOCK* Technology now included at no cost To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message