Hi. On 05/06/10 10:45, Maxim Levitsky wrote: > On Sat, 2010-06-05 at 03:36 +0300, Maxim Levitsky wrote: >> On Sat, 2010-06-05 at 09:58 +1000, Nigel Cunningham wrote: >>> Hi Maxim. >>> >>> On 05/06/10 09:39, Maxim Levitsky wrote: >>>> On Thu, 2010-06-03 at 16:50 +0200, Pavel Machek wrote: >>>>> >>>>> "Nigel Cunningham"<ncunningham@xxxxxxxxxxx> wrote: >>>>> >>>>>> Hi. >>>>>> >>>>>> On 30/05/10 15:25, Pavel Machek wrote: >>>>>>> Hi! >>>>>>> >>>>>>>> 2. Prior to writing any of the image, also set up new 4k page tables >>>>>>>> such that an attempt to make a change to any of the pages we're about to >>>>>>>> write to disk will result in a page fault, giving us an opportunity to >>>>>>>> flag the page as needing an atomic copy later. Once this is done, write >>>>>>>> protection for the page can be disabled and the write that caused the >>>>>>>> fault allowed to proceed. >>>>>>> >>>>>>> Tricky. >>>>>>> >>>>>>> page faulting code touches memory, too... >>>>>> >>>>>> Yeah. I realise we'd need to make the pages that are used to record the >>>>>> faults be unprotected themselves. I'm imagining a bitmap for that. >>>>>> >>>>>> Do you see any reason that it could be inherently impossible? That's >>>>>> what I really want to know before (potentially) wasting time trying it. >>>>> >>>>> I'm not sure it is impossible, but it certainly seems way too complex to be >>>>> practical. >>>>> >>>>> 2mb pages will probably present a problem, as will bat mappings on powerpc. >>>> >>>> >>>> Some time ago, after tuxonce caused medium fs corruption twice on my >>>> root filesystem (superblock gone for example), I was thinking too about >>>> how to make it safe to save whole memory. >>> >>> I'd be asking why you got the corruption. On the odd occasion where it >>> has been reported, it's usually been because the person didn't set up >>> their initramfs correctly (resumed after mounting filesystems). Is there >>> any chance that you did that? > I didn't use any initramfs. > I did use kernel modesetting and nouveau. > I used ext4. > The corruption happened after normal suspend. What's 'normal suspend'? > I replaces swsusp with tuxonice. > > Anyway, some more or less verified method must be used to save memory > because fs corruption is too scary thing to have. Agreed. > I can't say it scared me that much 'cause I had dealt with worse > corruptions before, but being thrown to "grub rescue>" on boot is not > pleasant thing to see. Oh, I agree and don't want anyone to ever experience corruption because of TuxOnIce. Unfortunately my wishes don't just happen :) Nigel _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
