From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([66.187.233.31]) by bombadil.infradead.org with esmtp (Exim 4.68 #1 (Red Hat Linux)) id 1K6mRl-0003Sl-O2 for kexec@lists.infradead.org; Thu, 12 Jun 2008 13:02:37 +0000 Date: Thu, 12 Jun 2008 09:02:25 -0400 From: Vivek Goyal Subject: Re: [PATCH -mm 2/2] kexec jump -v11: save/restore device state Message-ID: <20080612130225.GA9654@redhat.com> References: <1213082106.22608.30.camel@caritas-dev.intel.com> <20080611163026.GG6450@redhat.com> <1213232019.21353.8.camel@caritas-dev.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1213232019.21353.8.camel@caritas-dev.intel.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: "Huang, Ying" Cc: nigel@nigel.suspend2.net, Kexec Mailing List , linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , "Eric W. Biederman" , Pavel Machek , Andrew Morton , linux-pm@lists.linux-foundation.org T24gVGh1LCBKdW4gMTIsIDIwMDggYXQgMDg6NTM6MzlBTSArMDgwMCwgSHVhbmcsIFlpbmcgd3Jv dGU6Cj4gT24gV2VkLCAyMDA4LTA2LTExIGF0IDEyOjMwIC0wNDAwLCBWaXZlayBHb3lhbCB3cm90 ZToKPiBbLi4uXQo+ID4gPiBVc2FnZSBleGFtcGxlIG9mIHNpbXBsZSBoaWJlcm5hdGlvbjoKPiA+ ID4gCj4gPiA+IDEuIENvbXBpbGUgYW5kIGluc3RhbGwgcGF0Y2hlZCBrZXJuZWwgd2l0aCBmb2xs b3dpbmcgb3B0aW9ucyBzZWxlY3RlZDoKPiA+ID4gCj4gPiA+IENPTkZJR19YODZfMzI9eQo+ID4g PiBDT05GSUdfUkVMT0NBVEFCTEU9eQo+ID4gPiBDT05GSUdfS0VYRUM9eQo+ID4gPiBDT05GSUdf Q1JBU0hfRFVNUD15Cj4gPiA+IENPTkZJR19QTT15Cj4gPiA+IAo+ID4gPiAyLiBCdWlsZCBhbiBp bml0cmFtZnMgaW1hZ2UgY29udGFpbnMga2V4ZWMtdG9vbCBhbmQgbWFrZWR1bXBmaWxlLCBvcgo+ ID4gPiAgICBkb3dubG9hZCB0aGUgcHJlLWJ1aWx0IGluaXRyYW1mcyBpbWFnZSwgY2FsbGVkIHJv b3Rmcy5neiBpbgo+ID4gPiAgICBmb2xsb3dpbmcgdGV4dC4KPiA+ID4gCj4gPiA+IDMuIFByZXBh cmUgYSBwYXJ0aXRpb24gdG8gc2F2ZSBtZW1vcnkgaW1hZ2Ugb2Ygb3JpZ2luYWwga2VybmVsLCBj YWxsZWQKPiA+ID4gICAgaGliZXJuYXRpbmcgcGFydGl0aW9uIGluIGZvbGxvd2luZyB0ZXh0Lgo+ ID4gPiAKPiA+ID4gNC4gQm9vdCBrZXJuZWwgY29tcGlsZWQgaW4gc3RlcCAxIChrZXJuZWwgQSku Cj4gPiA+IAo+ID4gPiA1LiBJbiB0aGUga2VybmVsIEEsIGxvYWQga2VybmVsIGNvbXBpbGVkIGlu IHN0ZXAgMSAoa2VybmVsIEIpIHdpdGgKPiA+ID4gICAgL3NiaW4va2V4ZWMuIFRoZSBzaGVsbCBj b21tYW5kIGxpbmUgY2FuIGJlIGFzIGZvbGxvdzoKPiA+ID4gCj4gPiA+ICAgIC9zYmluL2tleGVj IC0tbG9hZC1wcmVzZXJ2ZS1jb250ZXh0IC9ib290L2J6SW1hZ2UgLS1tZW0tbWluPTB4MTAwMDAw Cj4gPiA+ICAgICAgLS1tZW0tbWF4PTB4ZmZmZmZmIC0taW5pdHJkPXJvb3Rmcy5nego+ID4gPiAK PiA+ID4gNi4gQm9vdCB0aGUga2VybmVsIEIgd2l0aCBmb2xsb3dpbmcgc2hlbGwgY29tbWFuZCBs aW5lOgo+ID4gPiAKPiA+ID4gICAgL3NiaW4va2V4ZWMgLWUKPiA+ID4gCj4gPiA+IDcuIFRoZSBr ZXJuZWwgQiB3aWxsIGJvb3QgYXMgbm9ybWFsIGtleGVjLiBJbiBrZXJuZWwgQiB0aGUgbWVtb3J5 Cj4gPiA+ICAgIGltYWdlIG9mIGtlcm5lbCBBIGNhbiBiZSBzYXZlZCBpbnRvIGhpYmVybmF0aW5n IHBhcnRpdGlvbiBhcwo+ID4gPiAgICBmb2xsb3c6Cj4gPiA+IAo+ID4gPiAgICBqdW1wX2JhY2tf ZW50cnk9YGNhdCAvcHJvYy9jbWRsaW5lIHwgdHIgJyAnICdcbicgfCBncmVwIGtleGVjX2p1bXBf YmFja19lbnRyeSB8IGN1dCAtZCAnPSdgCj4gPiA+ICAgIGVjaG8gJGp1bXBfYmFja19lbnRyeSA+ IGtleGVjX2p1bXBfYmFja19lbnRyeQo+ID4gPiAgICBjcCAvcHJvYy92bWNvcmUgZHVtcC5lbGYK PiA+ID4gCj4gPiA+ICAgIFRoZW4geW91IGNhbiBzaHV0ZG93biB0aGUgbWFjaGluZSBhcyBub3Jt YWwuCj4gPiA+IAo+ID4gPiA4LiBCb290IGtlcm5lbCBjb21waWxlZCBpbiBzdGVwIDEgKGtlcm5l bCBDKS4gVXNlIHRoZSByb290ZnMuZ3ogYXMKPiA+ID4gICAgcm9vdCBmaWxlIHN5c3RlbS4KPiA+ ID4gCj4gPiAKPiA+IE9uZSBvZiB0aGUgY29uY2VybnMgcmFpc2VkIGJ5IGhpYmVybmF0aW9uIHBl b3BsZSBpbiB0aGUgcGFzdCB3YXMgdG8gdXNlCj4gPiBzaW5nbGUgYm9vdCBsb2FkZXIgZW50cnkg dG8gYm9vdCBub3JtYWxseSBhcyB3ZWxsIHdoaWxlIHJlc3VtaW5nIGEga2VybmVsLgo+ID4gCj4g PiBTbyBpbiB0aGlzIGNhc2UgYSB1c2VyIGVpdGhlciBuZWVkcyB0byBtYWludGFpbiB0d28gYm9v dC1sb2FkZXIgZW50cmllcwo+ID4gb3IgbW9kaWZ5IGl0IG9uIHRoZSBmbHkuIEkgd2lzaGVkIHRo ZXJlIHdhcyBhIGJldHRlciB3YXkgdG8gaGFuZGxlIHRoYXQuCj4gCj4g77u/Tm93IGl0IGlzIG5v dCBuZWVkZWQgdG8gaGF2ZSB0d28gYm9vdC1sb2FkZXIgZW50cmllcywganVzdCBvbmUgaXMKPiBl bm91Z2guIFN0ZXAgNCBhbmQgc3RlcCA4IGNhbiBzaGFyZSB0aGUgc2FtZSBib290LWxvYWRlciBl bnRyaWVzLiBUaGUKPiByb290ZnMuZ3ogY2FuIGJlIHRoZSBub3JtYWwgaW5pdHJhbWZzIG9yIGlu aXRyZCB3aGVuIGRlcGxveW1lbnQuIEluCj4gcm9vdGZzLmd6LCBpZiB0aGVyZSBpcyBhIHZhbGlk IGhpYmVybmF0aW9uIGltYWdlLCB0aGUgaGliZXJuYXRlZCBzeXN0ZW0KPiB3aWxsIGJlIHJlc3Rv cmVkLCBvdGhlcndpc2UsIG5vcm1hbCBib290IHByb2Nlc3MgZm9sbG93cy4KPiAKCkZldyB0aGlu Z3MgSSBkb24ndCB1bmRlcnN0YW5kLgoKLSBBcmUgeW91IHNheWluZyB0aGF0IGhpYmVybmF0ZWQg aW1hZ2Ugd2lsbCBiZSBzYXZlZCBpbiBpbml0cmQKICAocm9vdGZzLmd6KT8gQnV0IHRoYXQgc2F2 aW5nIGlzIG9ubHkgaW4gUkFNLCB3ZSBuZXZlciB3cml0ZSBiYWNrCiAgaXQgdG8gZGlzaz8KCi0g SSB0aG91Z2h0IHdlIHByb2JhYmx5IGhhdmUgdG8gZGVkaWNhdGUgYSByYXcgcGFydGl0aW9uIGtp bmQgb2YgdGhpbmcKICBmb3Igc2F2aW5nIGltYWdlIGFuZCB0aGVuIG1vZGlmeSBib290IGxvYWRl ciBjb21tYW5kIGxpbmUgdG8gc29tZXRoaW5nCiAgc2ltaWxhciB0bywgInJlc3VtZT1wYXJ0aXRp b24iLiBUaGVuIGluaXRyZCBjYW4gZ28gaHVudGluZyBmb3IgaW1hZ2UKICBpbiByZXNwZWN0aXZl IHBhcnRpdGlvbiAoYXMgc3BlY2lmaWVkIGJ5IGNvbW1hbmQgbGluZSBwYXJhbWV0ZXIpIGFuZCBp ZgogIGltYWdlIGlzIG5vdCBhdmFpbGFibGUgdGhlbiBjb250aW51ZSB3aXRoIG5vcm1hbCBib290 LgoKVGhhbmtzClZpdmVrCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fXwprZXhlYyBtYWlsaW5nIGxpc3QKa2V4ZWNAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRw Oi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2tleGVjCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760581AbYFLNDS (ORCPT ); Thu, 12 Jun 2008 09:03:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754419AbYFLNDI (ORCPT ); Thu, 12 Jun 2008 09:03:08 -0400 Received: from mx1.redhat.com ([66.187.233.31]:52972 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752808AbYFLNDH (ORCPT ); Thu, 12 Jun 2008 09:03:07 -0400 Date: Thu, 12 Jun 2008 09:02:25 -0400 From: Vivek Goyal To: "Huang, Ying" Cc: "Eric W. Biederman" , Pavel Machek , nigel@nigel.suspend2.net, "Rafael J. Wysocki" , Andrew Morton , linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org, Kexec Mailing List Subject: Re: [PATCH -mm 2/2] kexec jump -v11: save/restore device state Message-ID: <20080612130225.GA9654@redhat.com> References: <1213082106.22608.30.camel@caritas-dev.intel.com> <20080611163026.GG6450@redhat.com> <1213232019.21353.8.camel@caritas-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1213232019.21353.8.camel@caritas-dev.intel.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 12, 2008 at 08:53:39AM +0800, Huang, Ying wrote: > On Wed, 2008-06-11 at 12:30 -0400, Vivek Goyal wrote: > [...] > > > Usage example of simple hibernation: > > > > > > 1. Compile and install patched kernel with following options selected: > > > > > > CONFIG_X86_32=y > > > CONFIG_RELOCATABLE=y > > > CONFIG_KEXEC=y > > > CONFIG_CRASH_DUMP=y > > > CONFIG_PM=y > > > > > > 2. Build an initramfs image contains kexec-tool and makedumpfile, or > > > download the pre-built initramfs image, called rootfs.gz in > > > following text. > > > > > > 3. Prepare a partition to save memory image of original kernel, called > > > hibernating partition in following text. > > > > > > 4. Boot kernel compiled in step 1 (kernel A). > > > > > > 5. In the kernel A, load kernel compiled in step 1 (kernel B) with > > > /sbin/kexec. The shell command line can be as follow: > > > > > > /sbin/kexec --load-preserve-context /boot/bzImage --mem-min=0x100000 > > > --mem-max=0xffffff --initrd=rootfs.gz > > > > > > 6. Boot the kernel B with following shell command line: > > > > > > /sbin/kexec -e > > > > > > 7. The kernel B will boot as normal kexec. In kernel B the memory > > > image of kernel A can be saved into hibernating partition as > > > follow: > > > > > > jump_back_entry=`cat /proc/cmdline | tr ' ' '\n' | grep kexec_jump_back_entry | cut -d '='` > > > echo $jump_back_entry > kexec_jump_back_entry > > > cp /proc/vmcore dump.elf > > > > > > Then you can shutdown the machine as normal. > > > > > > 8. Boot kernel compiled in step 1 (kernel C). Use the rootfs.gz as > > > root file system. > > > > > > > One of the concerns raised by hibernation people in the past was to use > > single boot loader entry to boot normally as well while resuming a kernel. > > > > So in this case a user either needs to maintain two boot-loader entries > > or modify it on the fly. I wished there was a better way to handle that. > > Now it is not needed to have two boot-loader entries, just one is > enough. Step 4 and step 8 can share the same boot-loader entries. The > rootfs.gz can be the normal initramfs or initrd when deployment. In > rootfs.gz, if there is a valid hibernation image, the hibernated system > will be restored, otherwise, normal boot process follows. > Few things I don't understand. - Are you saying that hibernated image will be saved in initrd (rootfs.gz)? But that saving is only in RAM, we never write back it to disk? - I thought we probably have to dedicate a raw partition kind of thing for saving image and then modify boot loader command line to something similar to, "resume=partition". Then initrd can go hunting for image in respective partition (as specified by command line parameter) and if image is not available then continue with normal boot. Thanks Vivek