Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932799AbbHXNQ0 (ORCPT ); Mon, 24 Aug 2015 09:16:26 -0400 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:52789 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932640AbbHXNQW (ORCPT ); Mon, 24 Aug 2015 09:16:22 -0400 Date: Mon, 24 Aug 2015 14:15:57 +0100 From: Russell King - ARM Linux To: Linus Walleij Cc: Andrey Ryabinin , Arnd Bergmann , "linux-mm@kvack.org" , Catalin Marinas , Will Deacon , "linux-kernel@vger.kernel.org" , David Keitel , Andrey Ryabinin , Alexander Potapenko , "linux-arm-kernel@lists.infradead.org" , Andrew Morton , Dmitry Vyukov Subject: Re: [PATCH v2 5/5] arm64: add KASan support Message-ID: <20150824131557.GB7557@n2100.arm.linux.org.uk> References: <1431698344-28054-1-git-send-email-a.ryabinin@samsung.com> <1431698344-28054-6-git-send-email-a.ryabinin@samsung.com> <55AE56DB.4040607@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1586 Lines: 33 On Tue, Jul 21, 2015 at 11:27:56PM +0200, Linus Walleij wrote: > On Tue, Jul 21, 2015 at 4:27 PM, Andrey Ryabinin wrote: > > > I used vexpress. Anyway, it doesn't matter now, since I have an update > > with a lot of stuff fixed, and it works on hardware. > > I still need to do some work on it and tomorrow, probably, I will share. > > Ah awesome. I have a stash of ARM boards so I can test it on a > range of hardware once you feel it's ready. > > Sorry for pulling stuff out of your hands, people are excited about > KASan ARM32 as it turns out. People may be excited about it because it's a new feature, but we really need to consider whether gobbling up 512MB of userspace for it is a good idea or not. There are programs around which like to map large amounts of memory into their process space, and the more we steal from them, the more likely these programs are to fail. The other thing which I'm not happy about is having a 16K allocation per thread - the 16K allocation for the PGD is already prone to invoking the OOM killer after memory fragmentation has set in, we don't need another 16K allocation. We're going from one 16K allocation per process to that _and_ one 16K allocation per thread. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/