refcount of rx_buffer page will be added here originally, so prefetchw
is needed, but after commit 1793668c3b8c ("i40e/i40evf: Update code to
better handle incrementing page count"), and refcount is not added
everytime, so change prefetchw as prefetch,
now it mainly services page_address(), but which accesses struct page
only when WANT_PAGE_VIRTUAL or HASHED_PAGE_VIRTUAL is defined otherwise
it returns address based on offset, so we prefetch it conditionally
Jakub suggested to define prefetch_page_address in a common header
Reported-by: kernel test robot <l...@intel.com>
Suggested-by: Jakub Kicinski <k...@kernel.org>
Signed-off-by: Li RongQing <lirongq...@baidu.com>
---
diff with v2: fix a build warning -Wvisibility
diff with v1: create a common function prefetch_page_address
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 +-
include/linux/prefetch.h | 8 ++++++++
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 62f5b2d35f63..5f9fe55bb66d 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1953,7 +1953,7 @@ static struct i40e_rx_buffer *i40e_get_rx_buffer(struct
i40e_ring *rx_ring,
struct i40e_rx_buffer *rx_buffer;
rx_buffer = i40e_rx_bi(rx_ring, rx_ring->next_to_clean);
- prefetchw(rx_buffer->page);
+ prefetch_page_address(rx_buffer->page);
/* we are reusing so sync this buffer for CPU use */
dma_sync_single_range_for_cpu(rx_ring->dev,
diff --git a/include/linux/prefetch.h b/include/linux/prefetch.h
index 13eafebf3549..b83a3f944f28 100644
--- a/include/linux/prefetch.h
+++ b/include/linux/prefetch.h
@@ -15,6 +15,7 @@
#include <asm/processor.h>
#include <asm/cache.h>
+struct page;
/*
prefetch(x) attempts to pre-emptively get the memory pointed to
by address "x" into the CPU L1 cache.
@@ -62,4 +63,11 @@ static inline void prefetch_range(void *addr, size_t len)
#endif
}
+static inline void prefetch_page_address(struct page *page)
+{
+#if defined(WANT_PAGE_VIRTUAL) || defined(HASHED_PAGE_VIRTUAL)
+ prefetch(page);
+#endif
+}
+
#endif
--
2.16.2
