From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/14961 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: New malloc - first preview Date: Thu, 28 Nov 2019 17:22:11 -0500 Message-ID: <20191128222211.GO16318@brightrain.aerifal.cx> References: <20191022174051.GA24726@brightrain.aerifal.cx> <20191128215642.GN16318@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="119845"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mutt/1.5.21 (2010-09-15) To: musl@lists.openwall.com Original-X-From: musl-return-14977-gllmg-musl=m.gmane.org@lists.openwall.com Thu Nov 28 23:22:25 2019 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.89) (envelope-from ) id 1iaSB7-000V3l-Ll for gllmg-musl@m.gmane.org; Thu, 28 Nov 2019 23:22:25 +0100 Original-Received: (qmail 3514 invoked by uid 550); 28 Nov 2019 22:22:23 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 3496 invoked from network); 28 Nov 2019 22:22:22 -0000 Content-Disposition: inline In-Reply-To: <20191128215642.GN16318@brightrain.aerifal.cx> Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:14961 Archived-At: On Thu, Nov 28, 2019 at 04:56:42PM -0500, Rich Felker wrote: > Work on the new malloc is well underway, and I have a draft version > now public at: > > https://github.com/richfelker/mallocng-draft > > Some highlights: > > - Smallest size-class now has 12 of 16 bytes usable for storage, > compared to 8 of 16 (32-bit archs) or 16 of 32 (64-bit archs) with > the old malloc, plus 1.5 bytes (32-bit) or 2.5 bytes (64-bit) of > out-of-band metadata. This overhead (5.5 or 6.5 bytes per > allocation) is uniform across all sizes. Make that 6 or 7 since there's also a 16-byte (counting alignment, which is most of it) group header that imposes 0.5 bytes of overhead per slot for a full-length 32-slot group. Rich