From: Ingo Molnar <mingo@elte.hu>
copy_page_range() triggers a CONFIG_DEBUG_HIGHMEM assert, because if a
preemption occurs right at a PMD_SIZE boundary the kmap/kunmap doesnt
match. This isnt a real problem because atomic_kunmap doesnt do anything
if CONFIG_DEBUG_HIGHMEM is not set and the atomic_map's are still correct,
but it's ugly nevertheless.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/mm/memory.c | 16 ++++++++--------
1 files changed, 8 insertions(+), 8 deletions(-)
diff -puN mm/memory.c~fix-config_debug_highmem-assert-in-copy_page_range mm/memory.c
--- 25/mm/memory.c~fix-config_debug_highmem-assert-in-copy_page_range Thu Sep 30 15:28:10 2004
+++ 25-akpm/mm/memory.c Thu Sep 30 15:28:10 2004
@@ -329,14 +329,6 @@ skip_copy_pte_range:
set_pte(dst_pte, pte);
page_dup_rmap(page);
cont_copy_pte_range_noset:
- address += PAGE_SIZE;
- if (address >= end) {
- pte_unmap_nested(src_pte);
- pte_unmap(dst_pte);
- goto out_unlock;
- }
- src_pte++;
- dst_pte++;
/*
* We are holding two locks at this point -
* any of them could generate latencies in
@@ -356,6 +348,14 @@ cont_copy_pte_range_noset:
dst_pte = pte_offset_map(dst_pmd, address);
src_pte = pte_offset_map_nested(src_pmd, address);
}
+ address += PAGE_SIZE;
+ if (address >= end) {
+ pte_unmap_nested(src_pte);
+ pte_unmap(dst_pte);
+ goto out_unlock;
+ }
+ src_pte++;
+ dst_pte++;
} while ((unsigned long)src_pte & PTE_TABLE_MASK);
pte_unmap_nested(src_pte-1);
pte_unmap(dst_pte-1);
_