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: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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16
mm/vmalloc.c
16
mm/vmalloc.c
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@ -910,7 +910,6 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
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struct vmap_block *vb;
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unsigned long addr = 0;
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unsigned int order;
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int purge = 0;
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BUG_ON(size & ~PAGE_MASK);
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BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
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@ -934,17 +933,7 @@ again:
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if (vb->free < 1UL << order)
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goto next;
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i = bitmap_find_free_region(vb->alloc_map,
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VMAP_BBMAP_BITS, order);
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if (i < 0) {
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if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
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/* fragmented and no outstanding allocations */
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BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
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purge = 1;
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}
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goto next;
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}
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i = VMAP_BBMAP_BITS - vb->free;
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addr = vb->va->va_start + (i << PAGE_SHIFT);
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BUG_ON(addr_to_vb_idx(addr) !=
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addr_to_vb_idx(vb->va->va_start));
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@ -960,9 +949,6 @@ next:
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spin_unlock(&vb->lock);
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}
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if (purge)
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purge_fragmented_blocks_thiscpu();
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put_cpu_var(vmap_block_queue);
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rcu_read_unlock();
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