[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? 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__*/ - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
