On Tuesday 06 March 2007, Rafael J. Wysocki wrote: > [changed Cc list] > > On Sunday, 25 February 2007 18:14, Andrey Borzenkov wrote: > > On Воскресенье 25 февраля 2007, Rafael J. Wysocki wrote: > > > On Sunday, 25 February 2007 11:37, Andrey Borzenkov wrote: > > > > On Воскресенье 25 февраля 2007, Rafael J. Wysocki wrote: > > > > > On Sunday, 25 February 2007 00:26, Andrey Borzenkov wrote: > > > > > > On Суббота 24 февраля 2007, Rafael J. Wysocki wrote: > > > > > > > Hi, > > > > > > > > > > > > > > On Saturday, 24 February 2007 10:55, Andrey Borzenkov wrote: > > > > > > > > On Вторник 13 февраля 2007, Andrey Borzenkov wrote: > > > > > > > > > On Четверг 07 декабря 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. > > > > It appears that for low memory kernel will ignore incomplete pages for > > sure. I hope it does the same for high memory - but for now I just throw > > this in and pray :) This also significantly simplifies patch. > > Well, can you please check if the appended modification of your patch still > works? > what is the state of this problem? It is still not fixed in 2.6.22-rc2 and this patch no more applies as well (changes are trivial but I cannot test them because USB refuses to suspend on my system in this version :) In previous versions patch worked just fine. This is http://bugzilla.kernel.org/show_bug.cgi?id=7995 BTW. > Thanks, > Rafael > > > --- > arch/i386/kernel/e820.c | 47 > +++++++++++++++++++++++++++++++++++++++++++++++ arch/i386/kernel/setup.c | > 1 + > include/asm-i386/e820.h | 1 + > 3 files changed, 49 insertions(+) > > Index: linux-2.6.21-rc2/arch/i386/kernel/e820.c > =================================================================== > --- linux-2.6.21-rc2.orig/arch/i386/kernel/e820.c > +++ linux-2.6.21-rc2/arch/i386/kernel/e820.c > @@ -313,6 +313,53 @@ static int __init request_standard_resou > > subsys_initcall(request_standard_resources); > > +/* > + * Mark pages corresponding to given pfn range as 'nosave'. > + */ > +static void __init > +e820_mark_nosave_range(unsigned long start_pfn, unsigned long end_pfn) > +{ > + unsigned long pfn; > + > + if (start_pfn >= end_pfn) > + return; > + > + printk("Nosave address range: %016Lx - %016Lx\n", > + PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); > + for (pfn = start_pfn; pfn < end_pfn; pfn++) > + if (pfn_valid(pfn)) > + SetPageNosave(pfn_to_page(pfn)); > +} > + > +/* > + * Find the ranges of physical addresses that do not correspond to > + * e820 RAM areas and mark the corresponding pages as nosave for software > + * suspend and suspend to RAM. > + * > + * This function requires the e820 map to be sorted and without any > + * overlapping entries and assumes the first e820 area to be RAM. > + */ > +void __init e820_mark_nosave_regions(void) > +{ > + int i; > + unsigned long pfn; > + > + pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size); > + for (i = 1; i < e820.nr_map; i++) { > + struct e820entry *ei = &e820.map[i]; > + > + if (pfn < PFN_UP(ei->addr)) > + e820_mark_nosave_range(pfn, PFN_UP(ei->addr)); > + > + pfn = PFN_DOWN(ei->addr + ei->size); > + if (ei->type != E820_RAM) > + e820_mark_nosave_range(PFN_UP(ei->addr), pfn); > + > + if (pfn >= max_low_pfn) > + break; > + } > +} > + > void __init add_memory_region(unsigned long long start, > unsigned long long size, int type) > { > Index: linux-2.6.21-rc2/arch/i386/kernel/setup.c > =================================================================== > --- linux-2.6.21-rc2.orig/arch/i386/kernel/setup.c > +++ linux-2.6.21-rc2/arch/i386/kernel/setup.c > @@ -648,6 +648,7 @@ void __init setup_arch(char **cmdline_p) > #endif > > e820_register_memory(); > + e820_mark_nosave_regions(); > > #ifdef CONFIG_VT > #if defined(CONFIG_VGA_CONSOLE) > Index: linux-2.6.21-rc2/include/asm-i386/e820.h > =================================================================== > --- linux-2.6.21-rc2.orig/include/asm-i386/e820.h > +++ linux-2.6.21-rc2/include/asm-i386/e820.h > @@ -43,6 +43,7 @@ extern void register_bootmem_low_pages(u > extern void e820_register_memory(void); > extern void limit_regions(unsigned long long size); > extern void print_memory_map(char *who); > +extern void e820_mark_nosave_regions(void); > > #endif/*!__ASSEMBLY__*/
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