Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754601Ab3CKVGe (ORCPT ); Mon, 11 Mar 2013 17:06:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60505 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754132Ab3CKVGd (ORCPT ); Mon, 11 Mar 2013 17:06:33 -0400 Date: Mon, 11 Mar 2013 17:06:28 -0400 From: Vivek Goyal To: Yinghai Lu Cc: "Eric W. Biederman" , "H. Peter Anvin" , Konrad Rzeszutek Wilk , Thomas Gleixner , Ingo Molnar , WANG Chao , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86, kdump: Set crashkernel_low automatically Message-ID: <20130311210628.GG14738@redhat.com> References: <513E28B8.3000502@zytor.com> <20130311192021.GF12107@redhat.com> <513E36CB.5040908@zytor.com> <20130311201245.GC14738@redhat.com> <513E3C44.9030402@zytor.com> <87hakhk6xu.fsf@xmission.com> <20130311204530.GE14738@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1746 Lines: 39 On Mon, Mar 11, 2013 at 01:57:41PM -0700, Yinghai Lu wrote: > On Mon, Mar 11, 2013 at 1:45 PM, Vivek Goyal wrote: > > In my experience, trying to keep foot-print small has kind of been a > > losing battle. > > > > - People want more functionality in second kernel, want to dump to more > > complicated IO stacks and that requires pulling in more drivers, > > more libraries, more daemons, more user space tools and what not. > > > > - Now we use dracut generated initramfs and it has been growing in size. > > Now systemd has been pulled in too. > > > > - Drivers keep on increasing their memory usage. > > If the dump file will be only put one place, why should all the drivers > for all devices get loaded? > for example: dump will be on disk with one scsi controller, can you only > load driver that contoller? and forget about all other storage controller and > network etc drivers. We do try to optimize things this way. Only include drivers as needed. But a single driver might be handling lots of cards and then try to bring up all the cards in second kernel. Just fixed some issues with one driver where around 40MB extra memory was benig consumed because of multiqueue support. Just bunch of allocation in driver. And we used kernel command line to disable it. Point being, in practice how many software development areas one can change to keep memory requirement with-in few MBs. I have been doing it for last few years and it has been very hard. Thanks Vivek -- 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/