From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vivek Goyal Subject: Re: kdump failed because of hotplug memory adding in kdump kernel Date: Thu, 9 Jan 2014 13:23:10 -0500 Message-ID: <20140109182310.GG25897@redhat.com> References: <52CD6E33.400@redhat.com> <20140108155829.GC13649@redhat.com> <8500545.JVNPnKcyD1@vostro.rjw.lan> <1389226308.1792.39.camel@misato.fc.hp.com> <20140109145035.GB25897@redhat.com> <1389283439.1792.66.camel@misato.fc.hp.com> <20140109162427.GF25897@redhat.com> <1389288265.1792.108.camel@misato.fc.hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1389288265.1792.108.camel-RbGIw1UOYPVo/CpIj0byZw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+glkk-kexec=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Toshi Kani Cc: Baoquan , kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, "Rafael J. Wysocki" , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, tangchen-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, zhangyanfei-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org, dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org List-Id: linux-acpi@vger.kernel.org On Thu, Jan 09, 2014 at 10:24:25AM -0700, Toshi Kani wrote: [..] > > I think creating a new command line option is simpler as compared to > > creating a new flag in bootparam which in turn disables memory hotplug. > > More users can use that option. For example, if for some reason hotplug > > code is crashing, one can just disable it on command line as work around > > and move on. > > I do not have a strong opinion about having such option. However, I > think it is more user friendly to keep the exactmap option works alone > on any platforms. I think we should create internally a variable which will disable memory hotplug. And set that variable based on memmap=exactmap, mem=X and also provide a way to disable memory hotplug directly using command line option. Current kexec-tools can use memmap=exactmap and be happy. I am writing a new kexec syscall and will not be using memmap=exactmap and would need to use that command line option to disable memory hotplug behavior. Thanks Vivek