Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3fcd76e8 authored by Zhang Yanfei's avatar Zhang Yanfei Committed by Linus Torvalds
Browse files

mm/vmalloc.c: remove dead code in vb_alloc 



Space in a vmap block that was once allocated is considered dirty and
not made available for allocation again before the whole block is
recycled.  The result is that free space within a vmap block is always
contiguous.

So if a vmap block has enough free space for allocation, the allocation
is impossible to fail.  Thus, the fragmented block purging was never
invoked from vb_alloc().  So remove this dead code.

[ Same patches also sent by:

    Chanho Min <chanho.min@lge.com>
    Johannes Weiner <hannes@cmpxchg.org>

  but git doesn't do "multiple authors" ]

Signed-off-by: default avatarZhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ab15d9b4

mm/vmalloc.c

+1 −15
Original line number Diff line number Diff line
@@ -910,7 +910,6 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask) 
	struct vmap_block *vb;

	unsigned long addr = 0;

	unsigned int order;

	int purge = 0;



	BUG_ON(size & ~PAGE_MASK);

	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
@@ -934,17 +933,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask) 
		if (vb->free < 1UL << order)

			goto next;



		i = bitmap_find_free_region(vb->alloc_map,

						VMAP_BBMAP_BITS, order);



		if (i < 0) {

			if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {

				/* fragmented and no outstanding allocations */

				BUG_ON(vb->dirty != VMAP_BBMAP_BITS);

				purge = 1;

			}

			goto next;

		}

		i = VMAP_BBMAP_BITS - vb->free;

		addr = vb->va->va_start + (i << PAGE_SHIFT);

		BUG_ON(addr_to_vb_idx(addr) !=

				addr_to_vb_idx(vb->va->va_start));
@@ -960,9 +949,6 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask) 
		spin_unlock(&vb->lock);

	}



	if (purge)

		purge_fragmented_blocks_thiscpu();



	put_cpu_var(vmap_block_queue);

	rcu_read_unlock();