| Message ID | 20171022005030.19175.91947.stgit@localhost.localdomain |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Kirsher |
| Headers | show |
| Series | [jkirsher/next-queue] i40e/i40evf: Revert "i40e/i40evf: bump tail only in multiples of 8" | expand |
> -----Original Message----- > From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On > Behalf Of Alexander Duyck > Sent: Saturday, October 21, 2017 5:52 PM > To: netdev@vger.kernel.org; intel-wired-lan@lists.osuosl.org; > akp@cohaesio.com; pstaszewski@itcare.pl > Subject: [Intel-wired-lan] [jkirsher/next-queue PATCH] i40e/i40evf: Revert > "i40e/i40evf: bump tail only in multiples of 8" > > From: Alexander Duyck <alexander.h.duyck@intel.com> > > This reverts commit 11f29003d6376fb123b7c3779dba49bb56fb0815. > > I am reverting this as I am fairly certain this can result in a memory leak when > combined with the current page recycling scheme. Specifically we end up > attempting to allocate fewer buffers than we recycled and this results in us > rewinding the next to alloc pointer which leads to leaks when we overwrite > the rx_buffer_info when processing the next frame. > > Fixes: 11f29003d637 ("i40e/i40evf: bump tail only in multiples of 8") > Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> > --- > drivers/net/ethernet/intel/i40e/i40e_txrx.c | 9 --------- > drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 9 --------- > 2 files changed, 18 deletions(-) Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index edbc94c4353d..487e2f483fa1 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -1407,15 +1407,6 @@ bool i40e_alloc_rx_buffers(struct i40e_ring *rx_ring, u16 cleaned_count) union i40e_rx_desc *rx_desc; struct i40e_rx_buffer *bi; - /* Hardware only fetches new descriptors in cache lines of 8, - * essentially ignoring the lower 3 bits of the tail register. We want - * to ensure our tail writes are aligned to avoid unnecessary work. We - * can't simply round down the cleaned count, since we might fail to - * allocate some buffers. What we really want is to ensure that - * next_to_used + cleaned_count produces an aligned value. - */ - cleaned_count -= (ntu + cleaned_count) & 0x7; - /* do nothing if no valid netdev defined */ if (!rx_ring->netdev || !cleaned_count) return false; diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index 6806ada11490..fe817e2b6fef 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c @@ -711,15 +711,6 @@ bool i40evf_alloc_rx_buffers(struct i40e_ring *rx_ring, u16 cleaned_count) union i40e_rx_desc *rx_desc; struct i40e_rx_buffer *bi; - /* Hardware only fetches new descriptors in cache lines of 8, - * essentially ignoring the lower 3 bits of the tail register. We want - * to ensure our tail writes are aligned to avoid unnecessary work. We - * can't simply round down the cleaned count, since we might fail to - * allocate some buffers. What we really want is to ensure that - * next_to_used + cleaned_count produces an aligned value. - */ - cleaned_count -= (ntu + cleaned_count) & 0x7; - /* do nothing if no valid netdev defined */ if (!rx_ring->netdev || !cleaned_count) return false;