Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753888AbbBJLcq (ORCPT ); Tue, 10 Feb 2015 06:32:46 -0500 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:60116 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750704AbbBJLco (ORCPT ); Tue, 10 Feb 2015 06:32:44 -0500 Date: Tue, 10 Feb 2015 11:32:30 +0000 From: Russell King - ARM Linux To: Gregory Fong Cc: Laura Abbott , Florian Fainelli , Kees Cook , Nicolas Pitre , Catalin Marinas , open list , Yalin Wang , "linux-arm-kernel@lists.infradead.org" , vishnu.ps@samsung.com, Marek Szyprowski Subject: Re: [PATCH] ARM: print cma-reserved pages from show_mem Message-ID: <20150210113230.GJ8656@n2100.arm.linux.org.uk> References: <1423092164-9145-1-git-send-email-gregory.0xf0@gmail.com> <54D40DAF.4080609@codeaurora.org> <54D534FB.1090101@codeaurora.org> 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: 1761 Lines: 39 On Mon, Feb 09, 2015 at 11:55:54AM -0800, Gregory Fong wrote: > On Fri, Feb 6, 2015 at 1:41 PM, Laura Abbott wrote: > > So it looks like the lib/show_mem.c does something different > > #ifdef CONFIG_CMA > > printk("%lu pages reserved\n", (reserved - totalcma_pages)); > > printk("%lu pages cma reserved\n", totalcma_pages); > > #else > > printk("%lu pages reserved\n", reserved); > > #endif > > > > > > No need to change the name, instead I'd say fix up arm to match what > > the generic showmem is doing. > > The trouble is that lib/show_mem.c and ARM's show_mem use the > 'reserved' variable to hold different info, which was not a problem I > was aiming to tackle here, and am not sure I understand what's going > on well enough to do so. But let's give it a shot: > > In lib/show_mem.c, reserved is calculated by iterating over all online > nodes, then increasing reserved by (zone->present_pages - > zone->managed_pages). This count includes CMA pages and so when > reserved pages is printed it should be 'reserved' - totalcma_pages, as > it currently is. So, some digging is needed into why the generic version is different. You have to remember that many of the algorithms for this kind of thing were based on the x86 implementation, so differences like this are probably down to ARM being annoyingly overlooked or ignored when generic changes happen. -- 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/