mm: rename _count, field of the struct page, to _refcount
Many developers already know that field for reference count of the
struct page is _count and atomic type. They would try to handle it
directly and this could break the purpose of page reference count
tracepoint. To prevent direct _count modification, this patch rename it
to _refcount and add warning message on the code. After that, developer
who need to handle reference count will find that field should not be
accessed directly.
[akpm@linux-foundation.org: fix comments, per Vlastimil]
[akpm@linux-foundation.org: Documentation/vm/transhuge.txt too]
[sfr@canb.auug.org.au: sync ethernet driver changes]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Sunil Goutham <sgoutham@cavium.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Manish Chopra <manish.chopra@qlogic.com>
Cc: Yuval Mintz <yuval.mintz@qlogic.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index f345679..bd94770 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -433,8 +433,8 @@
for (i = 0; i < MLX5_MPWRQ_PAGES_PER_WQE; i++) {
if (unlikely(mlx5e_alloc_and_map_page(rq, wi, i)))
goto err_unmap;
- atomic_add(mlx5e_mpwqe_strides_per_page(rq),
- &wi->umr.dma_info[i].page->_count);
+ page_ref_add(wi->umr.dma_info[i].page,
+ mlx5e_mpwqe_strides_per_page(rq));
wi->skbs_frags[i] = 0;
}
@@ -452,8 +452,8 @@
while (--i >= 0) {
dma_unmap_page(rq->pdev, wi->umr.dma_info[i].addr, PAGE_SIZE,
PCI_DMA_FROMDEVICE);
- atomic_sub(mlx5e_mpwqe_strides_per_page(rq),
- &wi->umr.dma_info[i].page->_count);
+ page_ref_sub(wi->umr.dma_info[i].page,
+ mlx5e_mpwqe_strides_per_page(rq));
put_page(wi->umr.dma_info[i].page);
}
dma_unmap_single(rq->pdev, wi->umr.mtt_addr, mtt_sz, PCI_DMA_TODEVICE);
@@ -477,8 +477,8 @@
for (i = 0; i < MLX5_MPWRQ_PAGES_PER_WQE; i++) {
dma_unmap_page(rq->pdev, wi->umr.dma_info[i].addr, PAGE_SIZE,
PCI_DMA_FROMDEVICE);
- atomic_sub(mlx5e_mpwqe_strides_per_page(rq) - wi->skbs_frags[i],
- &wi->umr.dma_info[i].page->_count);
+ page_ref_sub(wi->umr.dma_info[i].page,
+ mlx5e_mpwqe_strides_per_page(rq) - wi->skbs_frags[i]);
put_page(wi->umr.dma_info[i].page);
}
dma_unmap_single(rq->pdev, wi->umr.mtt_addr, mtt_sz, PCI_DMA_TODEVICE);
@@ -527,8 +527,8 @@
*/
split_page(wi->dma_info.page, MLX5_MPWRQ_WQE_PAGE_ORDER);
for (i = 0; i < MLX5_MPWRQ_PAGES_PER_WQE; i++) {
- atomic_add(mlx5e_mpwqe_strides_per_page(rq),
- &wi->dma_info.page[i]._count);
+ page_ref_add(&wi->dma_info.page[i],
+ mlx5e_mpwqe_strides_per_page(rq));
wi->skbs_frags[i] = 0;
}
@@ -551,8 +551,8 @@
dma_unmap_page(rq->pdev, wi->dma_info.addr, rq->wqe_sz,
PCI_DMA_FROMDEVICE);
for (i = 0; i < MLX5_MPWRQ_PAGES_PER_WQE; i++) {
- atomic_sub(mlx5e_mpwqe_strides_per_page(rq) - wi->skbs_frags[i],
- &wi->dma_info.page[i]._count);
+ page_ref_sub(&wi->dma_info.page[i],
+ mlx5e_mpwqe_strides_per_page(rq) - wi->skbs_frags[i]);
put_page(&wi->dma_info.page[i]);
}
}
diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
index 3aabfc0..73dd525 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -1036,7 +1036,7 @@
/* Incr page ref count to reuse on allocation failure
* so that it doesn't get freed while freeing SKB.
*/
- atomic_inc(¤t_bd->data->_count);
+ page_ref_inc(current_bd->data);
goto out;
}
@@ -1487,7 +1487,7 @@
* freeing SKB.
*/
- atomic_inc(&sw_rx_data->data->_count);
+ page_ref_inc(sw_rx_data->data);
rxq->rx_alloc_errors++;
qede_recycle_rx_bd_ring(rxq, edev,
fp_cqe->bd_num);