From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?B?SsO2cm4=?= Engel Subject: Re: LZMA inclusion Date: Mon, 8 Dec 2008 21:17:34 +0100 Message-ID: <20081208201734.GA4069@logfs.org> References: <492BA3FA.9010204@openwrt.org> <200812032348.36921.lasse.collin@tukaani.org> <200812062356.50734.lasse.collin@tukaani.org> <20081207160140.GA13387@logfs.org> <493C5D10.1040604@lougher.demon.co.uk> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <493C5D10.1040604@lougher.demon.co.uk> Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: Phillip Lougher Cc: Lasse Collin , Geert Uytterhoeven , Bernhard Reutner-Fischer , Tim Bird , glp@openwrt.org, linux-embedded@vger.kernel.org On Sun, 7 December 2008 23:32:32 +0000, Phillip Lougher wrote: >=20 > Currently, as mentioned above, Squashfs decompresses into a single=20 > contiguous output buffer. But, due to the linux kernel mailing list'= s=20 > dislike of vmalloc, this is being changed. Don't blame lkml, blame Intel and IBM. Back in the days of the 386, a beefy machine had 8MB of physical memory and 4GB of virtual memory space. Noone had to worry about fragmentation anymore. If you needed = a 1MB buffer, you'd just round up some 256 pages and instruct the mmu to map them into a large contiguous address range in the virtual address space. Life was good indeed. But physical memory has constantly grown since, while the virtual memor= y space has for a long time stagnated. Intel even introduced some hardware hacks to use up to 64GB of physical memory with a measly 4GB o= f virtual memory. Now it was _virtual_ memory fragmentation that you had to worry about. These days most CPUs you'd buy are 64bit, so virtual memory space has become useful again. But as a kernel hacker, you have little control over what hardware everyone is using. And those weird systems with more physical than virtual memory are still around. :( J=C3=B6rn --=20 Don't patch bad code, rewrite it. -- Kernigham and Pike, according to Rusty