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authorGuy Shapiro <guysh@mellanox.com>2015-04-15 18:17:57 +0300
committerDoug Ledford <dledford@redhat.com>2015-05-05 09:18:02 -0400
commit325ad0617adaf163e32dd2d857b90baf65a25b5b (patch)
tree13383cd4f5442a70bff01f0f55d8007fcb03002a /drivers/infiniband
parentc1d383b5785b1e0fb5fb862864712a7208219e6a (diff)
IB/core: dma unmap optimizations
While unmapping an ODP writable page, the dirty bit of the page is set. In order to do so, the head of the compound page is found. Currently, the compound head is found even on non-writable pages, where it is never used, leading to unnecessary cpu barrier that impacts performance. This patch moves the search for the compound head to be done only when needed. Signed-off-by: Guy Shapiro <guysh@mellanox.com> Acked-by: Shachar Raindel <raindel@mellanox.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/core/umem_odp.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
index aba47398880d..40becdb3196e 100644
--- a/drivers/infiniband/core/umem_odp.c
+++ b/drivers/infiniband/core/umem_odp.c
@@ -637,7 +637,6 @@ void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt,
idx = (addr - ib_umem_start(umem)) / PAGE_SIZE;
if (umem->odp_data->page_list[idx]) {
struct page *page = umem->odp_data->page_list[idx];
- struct page *head_page = compound_head(page);
dma_addr_t dma = umem->odp_data->dma_list[idx];
dma_addr_t dma_addr = dma & ODP_DMA_ADDR_MASK;
@@ -645,7 +644,8 @@ void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt,
ib_dma_unmap_page(dev, dma_addr, PAGE_SIZE,
DMA_BIDIRECTIONAL);
- if (dma & ODP_WRITE_ALLOWED_BIT)
+ if (dma & ODP_WRITE_ALLOWED_BIT) {
+ struct page *head_page = compound_head(page);
/*
* set_page_dirty prefers being called with
* the page lock. However, MMU notifiers are
@@ -656,6 +656,7 @@ void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt,
* be removed.
*/
set_page_dirty(head_page);
+ }
/* on demand pinning support */
if (!umem->context->invalidate_range)
put_page(page);