diff mbox series

[v2,net-next,23/26] igc: bail out early on XSK xmit if no descs are available

Message ID 20211123163955.154512-24-alexandr.lobakin@intel.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series net: introduce and use generic XDP stats | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 1 maintainers not CCed: intel-wired-lan@lists.osuosl.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 15 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Alexander Lobakin Nov. 23, 2021, 4:39 p.m. UTC 
There's no need to fetch an XSK pool desc in case our ring is full,
we can rather quit under unlikely branch.
Can't skip taking a lock here unfortunately since igc_desc_unused()
assumes we call it being locked.
This was designed to track xsk_tx::full counter, but won't hurt
either way.

Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 3 +++
 1 file changed, 3 insertions(+)

--
2.33.1
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 8e448288ee26..7d0c540d6b76 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -2604,6 +2604,8 @@  static void igc_xdp_xmit_zc(struct igc_ring *ring)
 	__netif_tx_lock(nq, cpu);

 	budget = igc_desc_unused(ring);
+	if (unlikely(!budget))
+		goto out_unlock;

 	while (xsk_tx_peek_desc(pool, &xdp_desc) && budget--) {
 		u32 cmd_type, olinfo_status;
@@ -2644,6 +2646,7 @@  static void igc_xdp_xmit_zc(struct igc_ring *ring)
 		xsk_tx_release(pool);
 	}

+out_unlock:
 	__netif_tx_unlock(nq);
 }