Messages in this thread Patch in this message | | | Date | Mon, 23 May 2005 14:06:29 -0700 | From | Chris Wright <> | Subject | [PATCH] mmap topdown fix for large stack limit, large allocation |
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The topdown changes in 2.6.12-rc1 can cause large allocations with large stack limit to fail, despite there being space available. The mmap_base-len is only valid when len >= mmap_base. However, nothing in topdown allocator checks this. It's only (now) caught at higher level, which will cause allocation to simply fail. The following change restores the fallback to bottom-up path, which will allow large allocations with large stack limit to potentially still succeed.
Signed-off-by: Chris Wright <chrisw@osdl.org> ---
mm/mmap.c | 4 ++++ 1 files changed, 4 insertions(+)
mm/mmap.c: de54acd9942f9929004921042721df5cdfe2b6c7 --- k/mm/mmap.c +++ l/mm/mmap.c @@ -1251,6 +1251,9 @@ arch_get_unmapped_area_topdown(struct fi return (mm->free_area_cache = addr-len); } + if (mm->mmap_base < len) + goto bottomup; + addr = mm->mmap_base-len; do { @@ -1268,6 +1271,7 @@ arch_get_unmapped_area_topdown(struct fi addr = vma->vm_start-len; } while (len < vma->vm_start); +bottomup: /* * A failed mmap() very likely causes application failure, * so fall back to the bottom-up function here. This scenario - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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