Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-02 00:51:44 +00:00
Code Issues Packages Projects Releases Wiki Activity

ixgbe: tweak page counting for XDP_REDIRECT

Browse Source 
The current page counting scheme assumes that the reference count
cannot decrease until the received frame is sent to the upper layers
of the networking stack. This assumption does not hold for the
XDP_REDIRECT action, since a page (pointed out by xdp_buff) can have
its reference count decreased via the xdp_do_redirect call.

To work around that, we now start off by a large page count and then
don't allow a refcount less than two.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This commit is contained in:
Björn Töpel 2018-03-22 10:02:36 +01:00 committed by Jeff Kirsher
parent 2eb34bafb3
commit ed93a39871
1 changed files with 4 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
View File

@ -1629,7 +1629,8 @@ static bool ixgbe_alloc_mapped_page(struct ixgbe_ring *rx_ring,
bi->dma = dma;
bi->page = page;
bi->page_offset = ixgbe_rx_offset(rx_ring);
bi->pagecnt_bias = 1;
page_ref_add(page, USHRT_MAX - 1);
bi->pagecnt_bias = USHRT_MAX;
rx_ring->rx_stats.alloc_rx_page++;
return true;
@ -2039,8 +2040,8 @@ static bool ixgbe_can_reuse_rx_page(struct ixgbe_rx_buffer *rx_buffer)
* the pagecnt_bias and page count so that we fully restock the
* number of references the driver holds.
*/
if (unlikely(!pagecnt_bias)) {
page_ref_add(page, USHRT_MAX);
if (unlikely(pagecnt_bias == 1)) {
page_ref_add(page, USHRT_MAX - 1);
rx_buffer->pagecnt_bias = USHRT_MAX;
}