diff options
| author | Eric Dumazet <[email protected]> | 2025-04-08 20:27:42 +0000 |
|---|---|---|
| committer | Jakub Kicinski <[email protected]> | 2025-04-10 01:03:31 +0000 |
| commit | 229671ac60e298b85c2644f52d7e487e9f487d06 (patch) | |
| tree | de47fc6ce5c2747e5774443dc8860e66d5c829b1 /net/core/lock_debug.c | |
| parent | octeontx2-pf: Add error log forcn10k_map_unmap_rq_policer() (diff) | |
| download | kernel-229671ac60e298b85c2644f52d7e487e9f487d06.tar.gz kernel-229671ac60e298b85c2644f52d7e487e9f487d06.zip | |
net: remove cpu stall in txq_trans_update()
txq_trans_update() currently uses txq->xmit_lock_owner
to conditionally update txq->trans_start.
For regular devices, txq->xmit_lock_owner is updated
from HARD_TX_LOCK() and HARD_TX_UNLOCK(), and this apparently
causes cpu stalls.
Using dev->lltx, which sits in a read-mostly cache-line,
and already used in HARD_TX_LOCK() and HARD_TX_UNLOCK()
helps cpu prediction.
On an AMD EPYC 7B12 dual socket server, tcp_rr with 128 threads
and 30,000 flows gets a 5 % increase in throughput.
As explained in commit 95ecba62e2fd ("net: fix races in
netdev_tx_sent_queue()/dev_watchdog()") I am planning
to no longer update txq->trans_start in the fast path
in a followup patch.
Signed-off-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Diffstat (limited to 'net/core/lock_debug.c')
0 files changed, 0 insertions, 0 deletions