On Mon, Oct 09, 2006 at 10:53:58AM +0100, Mel Gorman wrote: > On Fri, 6 Oct 2006, Vivek Goyal wrote: > > >On Fri, Oct 06, 2006 at 01:03:50PM -0500, Steve Fox wrote: > >>On Fri, 2006-10-06 at 18:11 +0100, Mel Gorman wrote: > >>>On (06/10/06 11:36), Vivek Goyal didst pronounce: > >>>>Where is bss placed in physical memory? I guess bss_start and bss_stop > >>>>from System.map will tell us. That will confirm that above memset step > >>>>is > >>>>stomping over bss. Then we have to just find that somewhere probably > >>>>we allocated wrong physical memory area for bootmem allocator map. > >>>> > >>> > >>>BSS is at 0x643000 -> 0x777BC4 > >>>init_bootmem wipes from 0x777000 -> 0x8F7000 > >>> > >>>So the BSS bytes from 0x777000 ->0x777BC4 (which looks very suspiciously > >>>pile a page alignment of addr & PAGE_MASK) gets set to 0xFF. One possible > >>>fix is below. It adds a check in bad_addr() to see if the BSS section is > >>>about to be used for bootmap. It Seems To Work For Me (tm) and > >>>illustrates > >>>the source of the problem even if it's not the 100% correct fix. > >> > >>I was able to boot the machine with Mel's patch applied on top of > >>-git22. > > > > > >Please have a look at the attached patch. Does it make some sense. > > > > It makes some sense. As you state, it wastes memory but that is better > than breaking. > > >Steve, can you please give this patch a try if it fixes the problem? > > > > I boottested the patch on the same machine as Steve was using and it > completed successfully. >
Hi Andrew, Can you please have a look at the attached patch and include it in -mm. This fixes the issue for steve. It also figures in the list of Adrian Bunk of known regressions. Subject : oops in xfrm_register_mode References : http://lkml.org/lkml/2006/10/4/170 Submitter : Steve Fox <[EMAIL PROTECTED]> Handled-By : Vivek Goyal <[EMAIL PROTECTED]> Status : patch available o Currently some code pieces assume that address returned by find_e820_area() are page aligned. But looks like find_e820_area() had no such intention and hence one might end up stomping over some of the data. One such case is bootmem allocator initialization code stomped over bss. o This patch modified find_e820_area() to return page aligned address. This might be little wasteful of memory but at the same time probably it is easier to handle page aligned memory. Signed-off-by: Vivek Goyal <[EMAIL PROTECTED]> --- arch/x86_64/kernel/e820.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff -puN arch/x86_64/kernel/e820.c~x86_64-return-page-aligned-phy-addr-from-find-e820-area arch/x86_64/kernel/e820.c --- linux-2.6.19-rc1-1M/arch/x86_64/kernel/e820.c~x86_64-return-page-aligned-phy-addr-from-find-e820-area 2006-10-06 15:28:13.000000000 -0400 +++ linux-2.6.19-rc1-1M-root/arch/x86_64/kernel/e820.c 2006-10-06 15:44:45.000000000 -0400 @@ -54,13 +54,13 @@ static inline int bad_addr(unsigned long /* various gunk below that needed for SMP startup */ if (addr < 0x8000) { - *addrp = 0x8000; + *addrp = PAGE_ALIGN(0x8000); return 1; } /* direct mapping tables of the kernel */ if (last >= table_start<<PAGE_SHIFT && addr < table_end<<PAGE_SHIFT) { - *addrp = table_end << PAGE_SHIFT; + *addrp = PAGE_ALIGN(table_end << PAGE_SHIFT); return 1; } @@ -68,18 +68,18 @@ static inline int bad_addr(unsigned long #ifdef CONFIG_BLK_DEV_INITRD if (LOADER_TYPE && INITRD_START && last >= INITRD_START && addr < INITRD_START+INITRD_SIZE) { - *addrp = INITRD_START + INITRD_SIZE; + *addrp = PAGE_ALIGN(INITRD_START + INITRD_SIZE); return 1; } #endif /* kernel code */ - if (last >= __pa_symbol(&_text) && last < __pa_symbol(&_end)) { - *addrp = __pa_symbol(&_end); + if (last >= __pa_symbol(&_text) && addr < __pa_symbol(&_end)) { + *addrp = PAGE_ALIGN(__pa_symbol(&_end)); return 1; } if (last >= ebda_addr && addr < ebda_addr + ebda_size) { - *addrp = ebda_addr + ebda_size; + *addrp = PAGE_ALIGN(ebda_addr + ebda_size); return 1; } @@ -152,7 +152,7 @@ unsigned long __init find_e820_area(unsi continue; while (bad_addr(&addr, size) && addr+size <= ei->addr+ei->size) ; - last = addr + size; + last = PAGE_ALIGN(addr) + size; if (last > ei->addr + ei->size) continue; if (last > end) _ - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
