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Commit 018771f4 authored by Roland Dreier's avatar Roland Dreier
Browse files

[IB] mthca: Fix doorbell record resource leak 



If we allocate a bunch of doorbell records and then free them, we'll
end up with completely empty pages, which we then free.  However, when
we come back to allocate more doorbell pages, we have to reallocate
those empty pages rather than always trying to take a slot that we've
never used.  If we don't, we eventually use up every slot and fail to
allocate a doorbell record, even though we have plenty of free space.

Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 8ddec746

drivers/infiniband/hw/mthca/mthca_memfree.c

+13 −4
Original line number Diff line number Diff line
@@ -529,12 +529,25 @@ int mthca_alloc_db(struct mthca_dev *dev, int type, u32 qn, __be32 **db) 
			goto found;

		}



	for (i = start; i != end; i += dir)

		if (!dev->db_tab->page[i].db_rec) {

			page = dev->db_tab->page + i;

			goto alloc;

		}



	if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {

		ret = -ENOMEM;

		goto out;

	}



	if (group == 0)

		++dev->db_tab->max_group1;

	else

		--dev->db_tab->min_group2;



	page = dev->db_tab->page + end;



alloc:

	page->db_rec = dma_alloc_coherent(&dev->pdev->dev, 4096,

					  &page->mapping, GFP_KERNEL);

	if (!page->db_rec) {
@@ -554,10 +567,6 @@ int mthca_alloc_db(struct mthca_dev *dev, int type, u32 qn, __be32 **db) 
	}



	bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);

	if (group == 0)

		++dev->db_tab->max_group1;

	else

		--dev->db_tab->min_group2;



found:

	j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);