diff options
| author | Jason Xing <kernelxing@tencent.com> | 2025-07-23 22:23:27 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-26 11:23:09 -0700 |
| commit | 3b7c13dfdcc26a78756cc17a23cdf4310c5a24a9 (patch) | |
| tree | 2a2575364c84f0701eff700e03f4c89b9de05656 /drivers | |
| parent | 2764ab51d5f0e8c7d3b7043af426b1883e3bde1d (diff) | |
igb: xsk: solve negative overflow of nb_pkts in zerocopy mode
There is no break time in the while() loop, so every time at the end of
igb_xmit_zc(), negative overflow of nb_pkts will occur, which renders
the return value always false. But theoretically, the result should be
set after calling xsk_tx_peek_release_desc_batch(). We can take
i40e_xmit_zc() as a good example.
Returning false means we're not done with transmission and we need one
more poll, which is exactly what igb_xmit_zc() always did before this
patch. After this patch, the return value depends on the nb_pkts value.
Two cases might happen then:
1. if (nb_pkts < budget), it means we process all the possible data, so
return true and no more necessary poll will be triggered because of
this.
2. if (nb_pkts == budget), it means we might have more data, so return
false to let another poll run again.
Fixes: f8e284a02afc ("igb: Add AF_XDP zero-copy Tx support")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Link: https://patch.msgid.link/20250723142327.85187-3-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/intel/igb/igb_xsk.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/net/ethernet/intel/igb/igb_xsk.c b/drivers/net/ethernet/intel/igb/igb_xsk.c index 5cf67ba292694..30ce5fbb5b776 100644 --- a/drivers/net/ethernet/intel/igb/igb_xsk.c +++ b/drivers/net/ethernet/intel/igb/igb_xsk.c @@ -482,7 +482,7 @@ bool igb_xmit_zc(struct igb_ring *tx_ring, struct xsk_buff_pool *xsk_pool) if (!nb_pkts) return true; - while (nb_pkts-- > 0) { + for (; i < nb_pkts; i++) { dma = xsk_buff_raw_get_dma(xsk_pool, descs[i].addr); xsk_buff_raw_dma_sync_for_device(xsk_pool, dma, descs[i].len); @@ -512,7 +512,6 @@ bool igb_xmit_zc(struct igb_ring *tx_ring, struct xsk_buff_pool *xsk_pool) total_bytes += descs[i].len; - i++; tx_ring->next_to_use++; tx_buffer_info->next_to_watch = tx_desc; if (tx_ring->next_to_use == tx_ring->count) |