Messages in this thread | | | From | "Chen, Yu C" <> | Subject | RE: [PATCH 3/3] PM / hibernate: Remove the restriction when checking memory size before/after hibernation | Date | Tue, 1 Sep 2015 09:54:31 +0000 |
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Hi Ingo, thanks for your review/suggestion,
> -----Original Message----- > From: Ingo Molnar [mailto:mingo.kernel.org@gmail.com] On Behalf Of Ingo > Molnar > Sent: Friday, August 28, 2015 1:38 PM > To: Chen, Yu C > Cc: tglx@linutronix.de; mingo@redhat.com; rjw@rjwysocki.net; > pavel@ucw.cz; hpa@zytor.com; Brown, Len; yinghai@kernel.org; > joeyli.kernel@gmail.com; Zhang, Rui; linux-pm@vger.kernel.org; linux- > kernel@vger.kernel.org > Subject: Re: [PATCH 3/3] PM / hibernate: Remove the restriction when > checking memory size before/after hibernation > > > * Chen Yu <yu.c.chen@intel.com> wrote: > > + /* > > + * No need to check num_physpages with get_num_physpages > > + * as we did before(please refer to git log), because > > + * is_nosave_page will ensure that each page is safe > > + * to be restored. > > + */ > > if (reason) { > > printk(KERN_ERR "PM: Image mismatch: %s\n", reason); > > return -EPERM; > > No, this removes a useful sanity check that protects against data corruption. > > If you want to relax it then you should add code that checks whether the > before/after memory image is truly a superset of each other, and warn and > deny the hibernation in any other case. (For example when RAM got > removed or moved.) > OK, I've sent out another patch based on pfn_mapped checking.thanks
Best Regards, Yu > Thanks, > > Ingo
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