mm, vmalloc: use well-defined find_last_bit() func (b136be5e) · Commits · 戴 / test

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>

mm/vmalloc.c

+6 −9

Original line number	Diff line number	Diff line
		@@ -1016,15 +1016,16 @@ void vm_unmap_aliases(void)

		rcu_read_lock();
		list_for_each_entry_rcu(vb, &vbq->free, free_list) {
		int i;
		int i, j;

		spin_lock(&vb->lock);
		i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
		while (i < VMAP_BBMAP_BITS) {
		if (i < VMAP_BBMAP_BITS) {
		unsigned long s, e;
		int j;
		j = find_next_zero_bit(vb->dirty_map,
		VMAP_BBMAP_BITS, i);

		j = find_last_bit(vb->dirty_map,
		VMAP_BBMAP_BITS);
		j = j + 1; /* need exclusive index */

		s = vb->va->va_start + (i << PAGE_SHIFT);
		e = vb->va->va_start + (j << PAGE_SHIFT);
		@@ -1034,10 +1035,6 @@ void vm_unmap_aliases(void)
		start = s;
		if (e > end)
		end = e;

		i = j;
		i = find_next_bit(vb->dirty_map,
		VMAP_BBMAP_BITS, i);
		}
		spin_unlock(&vb->lock);
		}

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