From owner-freebsd-hackers Thu Jul 15 21:57:53 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id CC1C0155AD for ; Thu, 15 Jul 1999 21:57:51 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id VAA15580; Thu, 15 Jul 1999 21:57:31 -0700 (PDT) (envelope-from dillon) Date: Thu, 15 Jul 1999 21:57:31 -0700 (PDT) From: Matthew Dillon Message-Id: <199907160457.VAA15580@apollo.backplane.com> To: "Daniel C. Sobral" Cc: freebsd-hackers@FreeBSD.ORG, tech-kern@netbsd.org Subject: Re: Swap overcommit (was Re: Replacement for grep(1) (part 2)) References: <19866.932086145@splode.eterna.com.au> <378EB49D.331D46DA@newsguy.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :Technical follow-up: : :Contrary to what I previously said, a number of tests reveal that :Solaris, indeed, does not overcommit. All non-read only segments, :and all malloc()ed memory is reserved upon exec() or fork(), and the :reserved memory is not allowed to exceed the total memory. It makes :extensive use of read only DATA segments, and has a NON_RESERVE :mmap() flag. : :Though the foot firmly planted in my mouth ought to prevent me from :saying anything else, I must say that it does explain a few things :to me... : :-- :Daniel C. Sobral (8-DCS) :dcs@newsguy.com Something is weird here. If the solaris people are using a SWAPSIZE + REALMEM VM model, they have to allow the allocated + reserved space go +REALMEM bytes over available swap space. If not they are using only a SWAPSIZE VM model. Wait - does Solaris normally use swap files or swap partitions? Or is it that weird /tmp filesystem stuff? If it normally uses swap files and allows holes then that explains everything. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message