Re: 2.6.38.2 breaks suspend to disk

[Yinghai Lu <yinghai@kernel.org>]

On 03/30/2011 11:32 AM, Michael Leun wrote:
> Hi,
>
> suspend to disk works with 2.6.38.1 but does not with 2.6.38.2 on my
> acer 1825ptz. Machine freezes after resume.
>
> git bisect yields:
>
> ml@jill:/usr/src/kernel/b/linux-2.6.38.y>  git bisect bad
> ff518ea26654e05d325d996f6e3a7f5f569cc2d5 is the first bad commit
> commit ff518ea26654e05d325d996f6e3a7f5f569cc2d5
> Author: Yinghai Lu<yinghai@kernel.org>
> Date:   Fri Feb 18 11:30:30 2011 +0000
>
>      x86: Cleanup highmap after brk is concluded
>
>      commit e5f15b45ddf3afa2bbbb10c7ea34fb32b6de0a0e upstream.
>
>      Now cleanup_highmap actually is in two steps: one is early in head64.c
>      and only clears above _end; a second one is in init_memory_mapping() and
>      tries to clean from _brk_end to _end.
>      It should check if those boundaries are PMD_SIZE aligned but currently
>      does not.
>      Also init_memory_mapping() is called several times for numa or memory
>      hotplug, so we really should not handle initial kernel mappings there.
>
>      This patch moves cleanup_highmap() down after _brk_end is settled so
>      we can do everything in one step.
>      Also we honor max_pfn_mapped in the implementation of cleanup_highmap.
>
>      Signed-off-by: Yinghai Lu<yinghai@kernel.org>
>      Signed-off-by: Stefano Stabellini<stefano.stabellini@eu.citrix.com>
>      LKML-Reference:<alpine.DEB.2.00.1103171739050.3382@kaball-desktop>
>      Signed-off-by: H. Peter Anvin<hpa@zytor.com>
>      Signed-off-by: Greg Kroah-Hartman<gregkh@suse.de>
>
> :040000 040000 b5ed0c2971ba1162c7cd289dd351d1700eb52fbc 8f830fdb43fa30ddebb485e6f6455d669300874b M      arch
>

can you please try following partial reverting patch?

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 7942335..07688d1 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -302,11 +302,11 @@ void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
  void __init cleanup_highmap(void)
  {
  	unsigned long vaddr = __START_KERNEL_map;
-	unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
  	unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
  	pmd_t *pmd = level2_kernel_pgt;
+	pmd_t *last_pmd = pmd + PTRS_PER_PMD;
  
-	for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
+	for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
  		if (pmd_none(*pmd))
  			continue;
  		if (vaddr < (unsigned long) _text || vaddr > end)