| Message ID | 20220930223324.1008555-1-anirudh.venkataramanan@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Anthony Nguyen |
| Headers | show |
| Series | [v2,net-next] e1000e: Remove unnecessary use of kmap_atomic() | expand |
On 10/1/2022 01:33, Anirudh Venkataramanan wrote: > alloc_rx_buf() allocates ps_page->page and buffer_info->page using either > GFP_ATOMIC or GFP_KERNEL. Memory allocated with GFP_KERNEL/GFP_ATOMIC can't > come from highmem and so there's no need to kmap() them. Just use > page_address(). > > I don't have access to a 32-bit system so did some limited testing on qemu > (qemu-system-i386 -m 4096 -smp 4 -device e1000e) with a 32-bit Debian 11.04 > image. > > v1->v2: > - update comment to remove a reference to kmap > > Cc: Ira Weiny <ira.weiny@intel.com> > Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com> > Cc: Jesse Brandeburg <jesse.brandeburg@intel.com> > Cc: Tony Nguyen <anthony.l.nguyen@intel.com> > Suggested-by: Ira Weiny <ira.weiny@intel.com> > Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> > Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> > --- > drivers/net/ethernet/intel/e1000e/netdev.c | 20 +++++--------------- > 1 file changed, 5 insertions(+), 15 deletions(-) Tested-by: Naama Meir <naamax.meir@linux.intel.com>
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 49e9269..5fb7891 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -1388,26 +1388,18 @@ static bool e1000_clean_rx_irq_ps(struct e1000_ring *rx_ring, int *work_done, /* page alloc/put takes too long and effects small * packet throughput, so unsplit small packets and - * save the alloc/put only valid in softirq (napi) - * context to call kmap_* + * save the alloc/put */ if (l1 && (l1 <= copybreak) && ((length + l1) <= adapter->rx_ps_bsize0)) { - u8 *vaddr; - ps_page = &buffer_info->ps_pages[0]; - /* there is no documentation about how to call - * kmap_atomic, so we can't hold the mapping - * very long - */ dma_sync_single_for_cpu(&pdev->dev, ps_page->dma, PAGE_SIZE, DMA_FROM_DEVICE); - vaddr = kmap_atomic(ps_page->page); - memcpy(skb_tail_pointer(skb), vaddr, l1); - kunmap_atomic(vaddr); + memcpy(skb_tail_pointer(skb), + page_address(ps_page->page), l1); dma_sync_single_for_device(&pdev->dev, ps_page->dma, PAGE_SIZE, @@ -1607,11 +1599,9 @@ static bool e1000_clean_jumbo_rx_irq(struct e1000_ring *rx_ring, int *work_done, */ if (length <= copybreak && skb_tailroom(skb) >= length) { - u8 *vaddr; - vaddr = kmap_atomic(buffer_info->page); - memcpy(skb_tail_pointer(skb), vaddr, + memcpy(skb_tail_pointer(skb), + page_address(buffer_info->page), length); - kunmap_atomic(vaddr); /* re-use the page, so don't erase * buffer_info->page */
alloc_rx_buf() allocates ps_page->page and buffer_info->page using either GFP_ATOMIC or GFP_KERNEL. Memory allocated with GFP_KERNEL/GFP_ATOMIC can't come from highmem and so there's no need to kmap() them. Just use page_address(). I don't have access to a 32-bit system so did some limited testing on qemu (qemu-system-i386 -m 4096 -smp 4 -device e1000e) with a 32-bit Debian 11.04 image. v1->v2: - update comment to remove a reference to kmap Cc: Ira Weiny <ira.weiny@intel.com> Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com> Cc: Tony Nguyen <anthony.l.nguyen@intel.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> --- drivers/net/ethernet/intel/e1000e/netdev.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-)