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mm, vmalloc: use well-defined find_last_bit() func

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Our intention in here is to find last_bit within the region to flush.
There is well-defined function, find_last_bit() for this purpose and its
performance may be slightly better than current implementation.  So change
it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joonsoo Kim 2013-09-11 14:21:40 -07:00 • committed by Linus Torvalds
commit b136be5e0b
1 changed files with 6 additions and 9 deletions
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15
mm/vmalloc.c
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@ -1016,15 +1016,16 @@ void vm_unmap_aliases(void)
rcu_read_lock(); rcu_read_lock();
list_for_each_entry_rcu(vb, &vbq->free, free_list) { list_for_each_entry_rcu(vb, &vbq->free, free_list) {
int i; int i, j;
spin_lock(&vb->lock); spin_lock(&vb->lock);
i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS); i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
while (i < VMAP_BBMAP_BITS) { if (i < VMAP_BBMAP_BITS) {
unsigned long s, e; unsigned long s, e;
int j;
j = find_next_zero_bit(vb->dirty_map, j = find_last_bit(vb->dirty_map,
VMAP_BBMAP_BITS, i); VMAP_BBMAP_BITS);
j = j + 1; /* need exclusive index */
s = vb->va->va_start + (i << PAGE_SHIFT); s = vb->va->va_start + (i << PAGE_SHIFT);
e = vb->va->va_start + (j << PAGE_SHIFT); e = vb->va->va_start + (j << PAGE_SHIFT);
@ -1034,10 +1035,6 @@ void vm_unmap_aliases(void)
start = s; start = s;
if (e > end) if (e > end)
end = e; end = e;
i = j;
i = find_next_bit(vb->dirty_map,
VMAP_BBMAP_BITS, i);
} }
spin_unlock(&vb->lock); spin_unlock(&vb->lock);
} }