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author | Joonsoo Kim <iamjoonsoo.kim@lge.com> | 2016-03-17 14:17:49 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-17 15:09:34 -0700 |
commit | f48d97f340cbb0c323fa7a7b36bd76a108a9f49f (patch) | |
tree | 0cc690e92bd4ba6408530b777d3fce63b89e926b | |
parent | 0335ddd34f39569a32096084bf3b0960d2b1212b (diff) | |
download | op-kernel-dev-f48d97f340cbb0c323fa7a7b36bd76a108a9f49f.zip op-kernel-dev-f48d97f340cbb0c323fa7a7b36bd76a108a9f49f.tar.gz |
mm/vmalloc: query dynamic DEBUG_PAGEALLOC setting
As CONFIG_DEBUG_PAGEALLOC can be enabled/disabled via kernel parameters
we can optimize some cases by checking the enablement state.
This is follow-up work for Christian's Optimize CONFIG_DEBUG_PAGEALLOC:
https://lkml.org/lkml/2016/1/27/194
Remaining work is to make sparc to be aware of this but it looks not
easy for me so I skip that in this series.
This patch (of 5):
We can disable debug_pagealloc processing even if the code is complied
with CONFIG_DEBUG_PAGEALLOC. This patch changes the code to query
whether it is enabled or not in runtime.
[akpm@linux-foundation.org: update comment, per David. Adjust comment to use 80 cols]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/vmalloc.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index fb42a5b..d4b2e34 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -531,22 +531,21 @@ static void unmap_vmap_area(struct vmap_area *va) static void vmap_debug_free_range(unsigned long start, unsigned long end) { /* - * Unmap page tables and force a TLB flush immediately if - * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free - * bugs similarly to those in linear kernel virtual address - * space after a page has been freed. + * Unmap page tables and force a TLB flush immediately if pagealloc + * debugging is enabled. This catches use after free bugs similarly to + * those in linear kernel virtual address space after a page has been + * freed. * - * All the lazy freeing logic is still retained, in order to - * minimise intrusiveness of this debugging feature. + * All the lazy freeing logic is still retained, in order to minimise + * intrusiveness of this debugging feature. * - * This is going to be *slow* (linear kernel virtual address - * debugging doesn't do a broadcast TLB flush so it is a lot - * faster). + * This is going to be *slow* (linear kernel virtual address debugging + * doesn't do a broadcast TLB flush so it is a lot faster). */ -#ifdef CONFIG_DEBUG_PAGEALLOC - vunmap_page_range(start, end); - flush_tlb_kernel_range(start, end); -#endif + if (debug_pagealloc_enabled()) { + vunmap_page_range(start, end); + flush_tlb_kernel_range(start, end); + } } /* |