Messages in this thread | | | Date | Thu, 17 Sep 2015 07:40:27 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH] [v2] PM / hibernate: Fix hibernation panic caused by inconsistent e820 map |
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Hi!
> PM: Image mismatch: memory size > > This is also because BIOS provides different e820 memory map before/after > hibernation, and linux regards it as invalid process and refuses to > resume, in order to protect against data corruption. However, > this check might be too strict, consider the following scenario:
Well... yes, the check is strict, but why is BIOS doing that? Can you fix it instead?
> The hibernating system has a smaller memory capacity than > the resuming system, and the former memory region is a subset of the > latter, it should be allowed to resume. Here is a case for this > situation: > > before hibernation: > > BIOS-e820: [mem 0x0000000020200000-0x0000000077517fff] usable > BIOS-e820: [mem 0x0000000077518000-0x0000000077567fff] reserved > Memory: 3871356K/4058428K available (7595K kernel code, 1202K rwdata, > 3492K rodata, 1400K init, 1308K bss, 187072K reserved, 0K cma-reserved) > > after hibernation: > BIOS-e820: [mem 0x0000000020200000-0x000000007753ffff] usable > BIOS-e820: [mem 0x0000000077540000-0x0000000077567fff] reserved > Memory: 3871516K/4058588K available (7595K kernel code, 1202K rwdata, > 3492K rodata, 1400K init, 1308K bss, 187072K reserved, 0K cma-reserved) > > According to above data, the number of present_pages has increased by > 40(thus 160K), linux will terminate the resuming process. But since > [0x0000000020200000-0x0000000077517fff] is a subset of > [0x0000000020200000-0x000000007753ffff], we should let system > resume.
Ok, complex, but will work. But what happens in the opposite case? On the next boot, bios gets you 160K less....
Can you do echo powerdown > /sys/power/disk to work around this?
Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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