]> git.openfabrics.org - ~shefty/rdma-dev.git/commitdiff
mm: bootmem: drop superfluous range check when freeing pages in bulk
authorJohannes Weiner <hannes@cmpxchg.org>
Tue, 10 Jan 2012 23:08:13 +0000 (15:08 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 11 Jan 2012 00:30:44 +0000 (16:30 -0800)
The area node_bootmem_map represents is aligned to BITS_PER_LONG, and all
bits in any aligned word of that map valid.  When the represented area
extends beyond the end of the node, the non-existant pages will be marked
as reserved.

As a result, when freeing a page block, doing an explicit range check for
whether that block is within the node's range is redundant as the bitmap
is consulted anyway to see whether all pages in the block are unreserved.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Uwe Kleine-K├Ânig <u.kleine-koenig@pengutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/bootmem.c

index 3e6f152f117e878a97572d881eb8606f885e0673..1aea171539acfa8c3babac3136df63795f09cb88 100644 (file)
@@ -197,7 +197,7 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
                idx = start - bdata->node_min_pfn;
                vec = ~map[idx / BITS_PER_LONG];
 
-               if (aligned && vec == ~0UL && start + BITS_PER_LONG <= end) {
+               if (aligned && vec == ~0UL) {
                        int order = ilog2(BITS_PER_LONG);
 
                        __free_pages_bootmem(pfn_to_page(start), order);