From owner-freebsd-hackers Sun Jan 26 04:36:04 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id EAA05281 for hackers-outgoing; Sun, 26 Jan 1997 04:36:04 -0800 (PST) Received: from root.com (implode.root.com [198.145.90.17]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id EAA05276 for ; Sun, 26 Jan 1997 04:36:01 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by root.com (8.7.6/8.6.5) with SMTP id EAA06772; Sun, 26 Jan 1997 04:35:36 -0800 (PST) Message-Id: <199701261235.EAA06772@root.com> X-Authentication-Warning: implode.root.com: Host localhost [127.0.0.1] didn't use HELO protocol To: Michael Hancock cc: proff@suburbia.net, hackers@FreeBSD.ORG Subject: Re: SLAB stuff, and applications to current net code (fwd) In-reply-to: Your message of "Sun, 26 Jan 1997 20:36:44 +0900." From: David Greenman Reply-To: dg@root.com Date: Sun, 26 Jan 1997 04:35:36 -0800 Sender: owner-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk >On Sun, 26 Jan 1997 proff@suburbia.net wrote: > >> Can anyone inform me what a SLAB allocator is, and if so, would freebsd >> benefit from one? >> > >It's a chunk of memory that you put multiple kernel objects of the same >type into. We have a modified mach zone allocator. They're both type >stable memory allocators. The memory allocator in BSD is *not* type-stable. >Maybe John or David will explain how our allocator differs from the >original zone allocator in 4.4BSD borrowed from Mach. There isn't a lot of difference. Just some performance improvements. >I not sure how much benefit the SLAB allocator would offer over what we >have. There's some extra overhead in maintaining a SLAB. > >BTW, SLAB is used in Solaris. The allocator in BSD is designed to be as fast as possible and trades space efficiency for performance. I'm very skeptical that a SLAB allocator would be any faster than the current allocation algorithm, although it would likely be more space efficient. -DG David Greenman Core-team/Principal Architect, The FreeBSD Project