On Sunday, 25 February 2007 11:37, Andrey Borzenkov wrote: > On ??????????? 25 ??????? 2007, Rafael J. Wysocki wrote: > > On Sunday, 25 February 2007 00:26, Andrey Borzenkov wrote: > > > On ??????? 24 ??????? 2007, Rafael J. Wysocki wrote: > > > > Hi, > > > > > > > > On Saturday, 24 February 2007 10:55, Andrey Borzenkov wrote: > > > > > On ??????? 13 ??????? 2007, Andrey Borzenkov wrote: > > > > > > On ??????? 07 ??????? 2006, Lebedev, Vladimir P wrote: > > > > > > > Please register new bug, attach acpidump and dmesg. > > > > > > > > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=7995 > > > > > > > > > > > > regards > > > > > > > > > > Well, this starts looking like ACPI is not at fault. > > > > > > > > > > When reporting AC state ACPI just reads contents of system memory (I > > > > > presume it gets updated by BIOS/ACPI when AC state changes). It looks > > > > > like this memory area is restored during resume from STD. I updated > > > > > mentioned bug report with more detailed description. Now if someone > > > > > could suggest a way to catch if specific physical address gets > > > > > saved/restored this would finally explain it. > > > > > > > > First, if you want the reserved memory areas to be left alone by > > > > swsusp, you need to mark them as 'nosave'. On x86_64 this is done by > > > > the function e820_mark_nosave_range() in arch/x86_64/kernel/e820.c that > > > > can be ported to i386 with no problems. However, we haven't found that > > > > very useful, so far, since no one has ever reported any problems with > > > > the current approach, which is to save and restore them. > > > > > > Well, the following proof of concept patch fixes this issue for me. > > > Please notice that original version of e820_mark_nosave_range() could > > > fail to exclude some areas due to alignment issues (exactly what happened > > > to me on first try) so it still can explain your problem too. > > > > Great job, thanks for the patch! It looks good, so I'm going to forward it > > for merging. > > > > Please no; I'm currently testing slightly more polished version; I will send > it later. OK > Could anybody explain (or give pointer to) what happens which region that is > not page-aligned? In particular, the very first one: > > BIOS-e820: 0000000000000000 - 000000000009fc00 (usable) > BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved) > > Will the kernel allocate partial page (how?) or will the kernel ignore last > (first) incomplete page? In the former case how those incomplete pages can be > detected? Well, on x86_64, if I understand e820_register_active_regions() correctly, the partial pages won't be registered. Greetings, Rafael
