From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen Yu Subject: Re: [PATCH] PM / hibernate: Introduce snapshot test mode for hibernation Date: Wed, 13 Jul 2016 18:20:05 +0800 Message-ID: <578615D5.3060501@intel.com> References: <1467873658-31986-1-git-send-email-yu.c.chen@intel.com> <20160713095005.GA27870@amd> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20160713095005.GA27870@amd> Sender: linux-kernel-owner@vger.kernel.org To: Pavel Machek Cc: linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Len Brown , linux-kernel@vger.kernel.org List-Id: linux-pm@vger.kernel.org Hi Pavel, thanks for your reply, On 2016=E5=B9=B407=E6=9C=8813=E6=97=A5 17:50, Pavel Machek wrote: > On Thu 2016-07-07 14:40:58, Chen Yu wrote: >> This mode is to verify if the snapshot data written to >> swap device can be successfully restored to memory. It >> is useful to ease the debugging process on hibernation, >> since this mode can not only bypass the BIOSen/bootloader, >> but also the system re-initialization. >> >> For example: >> $ sudo echo snapshot > /sys/power/disk >> $ sudo echo disk > /sys/power/state >> >> /* manual resume.*/ >> $ sudo echo 8:3 > /sys/power/resume > Your examples will not work, will they? It works on my platform, although I did not tested it for too many roun= ds. And here's a revised version of v2, which introduced a new test mode in pm_test, thus users do not need to run a manual resume. https://patchwork.kernel.org/patch/9226837/ > > This is also quite tricky/dangerous. If you do this with filesystems > mounted R/W, it is "good bye, filesystems". Ah, yes, this is quite tricky, maybe we can use this option as a debug=20 method, for example, boot with rootfs =3D initrd, without mounting any disks, and then swapon the swap device, and do a testing. This should be safer= ? > > I guess updating documentation would be welcome from my side, > otherwise it should be ok. OK, I'll update the documents. > > Acked-by: Pavel Machek thanks. > > Best regards, > Pavel >