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| author | Shannon Nelson <shannon.nelson@amd.com> | 2024-06-24 10:50:15 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-06-25 16:44:08 -0700 |
| commit | 84b767f9e34fdb143c09e66a2a20722fc2921821 (patch) | |
| tree | 808a4091a01f10e03d844bb0d3972a5cff981467 /drivers/net/ethernet/pensando/ionic/ionic_dev.h | |
| parent | b1c4b4d45263241ec6c2405a8df8265d4b58e707 (diff) | |
| download | lwn-84b767f9e34fdb143c09e66a2a20722fc2921821.tar.gz lwn-84b767f9e34fdb143c09e66a2a20722fc2921821.zip | |
ionic: use dev_consume_skb_any outside of napi
If we're not in a NAPI softirq context, we need to be careful
about how we call napi_consume_skb(), specifically we need to
call it with budget==0 to signal to it that we're not in a
safe context.
This was found while running some configuration stress testing
of traffic and a change queue config loop running, and this
curious note popped out:
[ 4371.402645] BUG: using smp_processor_id() in preemptible [00000000] code: ethtool/20545
[ 4371.402897] caller is napi_skb_cache_put+0x16/0x80
[ 4371.403120] CPU: 25 PID: 20545 Comm: ethtool Kdump: loaded Tainted: G OE 6.10.0-rc3-netnext+ #8
[ 4371.403302] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 01/23/2021
[ 4371.403460] Call Trace:
[ 4371.403613] <TASK>
[ 4371.403758] dump_stack_lvl+0x4f/0x70
[ 4371.403904] check_preemption_disabled+0xc1/0xe0
[ 4371.404051] napi_skb_cache_put+0x16/0x80
[ 4371.404199] ionic_tx_clean+0x18a/0x240 [ionic]
[ 4371.404354] ionic_tx_cq_service+0xc4/0x200 [ionic]
[ 4371.404505] ionic_tx_flush+0x15/0x70 [ionic]
[ 4371.404653] ? ionic_lif_qcq_deinit.isra.23+0x5b/0x70 [ionic]
[ 4371.404805] ionic_txrx_deinit+0x71/0x190 [ionic]
[ 4371.404956] ionic_reconfigure_queues+0x5f5/0xff0 [ionic]
[ 4371.405111] ionic_set_ringparam+0x2e8/0x3e0 [ionic]
[ 4371.405265] ethnl_set_rings+0x1f1/0x300
[ 4371.405418] ethnl_default_set_doit+0xbb/0x160
[ 4371.405571] genl_family_rcv_msg_doit+0xff/0x130
[...]
I found that ionic_tx_clean() calls napi_consume_skb() which calls
napi_skb_cache_put(), but before that last call is the note
/* Zero budget indicate non-NAPI context called us, like netpoll */
and
DEBUG_NET_WARN_ON_ONCE(!in_softirq());
Those are pretty big hints that we're doing it wrong. We can pass a
context hint down through the calls to let ionic_tx_clean() know what
we're doing so it can call napi_consume_skb() correctly.
Fixes: 386e69865311 ("ionic: Make use napi_consume_skb")
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://patch.msgid.link/20240624175015.4520-1-shannon.nelson@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/ethernet/pensando/ionic/ionic_dev.h')
| -rw-r--r-- | drivers/net/ethernet/pensando/ionic/ionic_dev.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h index f30eee4a5a80..b6c01a88098d 100644 --- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h +++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h @@ -375,7 +375,9 @@ typedef void (*ionic_cq_done_cb)(void *done_arg); unsigned int ionic_cq_service(struct ionic_cq *cq, unsigned int work_to_do, ionic_cq_cb cb, ionic_cq_done_cb done_cb, void *done_arg); -unsigned int ionic_tx_cq_service(struct ionic_cq *cq, unsigned int work_to_do); +unsigned int ionic_tx_cq_service(struct ionic_cq *cq, + unsigned int work_to_do, + bool in_napi); int ionic_q_init(struct ionic_lif *lif, struct ionic_dev *idev, struct ionic_queue *q, unsigned int index, const char *name, |