From: Stephen Hemminger <stephen@networkplumber.org>
To: davem@davemloft.net
Cc: netdev@vger.kernel.org,
Stephen Hemminger <stephen@networkplumber.org>,
Stephen Hemminger <sthemmin@microsoft.com>
Subject: [PATCH net-stable 14/24] hv_netvsc: fix race in napi poll when rescheduling
Date: Mon, 14 May 2018 15:32:13 -0700 [thread overview]
Message-ID: <20180514223223.25433-15-sthemmin@microsoft.com> (raw)
In-Reply-To: <20180514223223.25433-1-sthemmin@microsoft.com>
From: Stephen Hemminger <stephen@networkplumber.org>
commit d64e38ae690e3337db0d38d9b149a193a1646c4b upstream
There is a race between napi_reschedule and re-enabling interrupts
which could lead to missed host interrrupts. This occurs when
interrupts are re-enabled (hv_end_read) and vmbus irq callback
(netvsc_channel_cb) has already scheduled NAPI.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/hyperv/netvsc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index b7720b65f5d6..7e0eb99571af 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -1205,9 +1205,10 @@ int netvsc_poll(struct napi_struct *napi, int budget)
if (send_recv_completions(ndev, net_device, nvchan) == 0 &&
work_done < budget &&
napi_complete_done(napi, work_done) &&
- hv_end_read(&channel->inbound)) {
+ hv_end_read(&channel->inbound) &&
+ napi_schedule_prep(napi)) {
hv_begin_read(&channel->inbound);
- napi_reschedule(napi);
+ __napi_schedule(napi);
}
/* Driver may overshoot since multiple packets per descriptor */
--
2.17.0
next prev parent reply other threads:[~2018-05-14 22:32 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-14 22:31 [PATCH net-stable 00/24] hv_netvsc patches for 4.14 stable Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 01/24] hv_netvsc: Fix the real number of queues of non-vRSS cases Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 02/24] hv_netvsc: Rename ind_table to rx_table Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 03/24] hv_netvsc: Rename tx_send_table to tx_table Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 04/24] hv_netvsc: Add initialization of tx_table in netvsc_device_add() Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 05/24] hv_netvsc: Set tx_table to equal weight after subchannels open Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 06/24] hv_netvsc: netvsc_teardown_gpadl() split Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 07/24] hv_netvsc: preserve hw_features on mtu/channels/ringparam changes Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 08/24] hv_netvsc: empty current transmit aggregation if flow blocked Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 09/24] hv_netvsc: Use the num_online_cpus() for channel limit Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 10/24] hv_netvsc: avoid retry on send during shutdown Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 11/24] hv_netvsc: only wake transmit queue if link is up Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 12/24] hv_netvsc: fix error unwind handling if vmbus_open fails Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 13/24] hv_netvsc: cancel subchannel setup before halting device Stephen Hemminger
2018-05-14 22:32 ` Stephen Hemminger [this message]
2018-05-14 22:32 ` [PATCH net-stable 15/24] hv_netvsc: defer queue selection to VF Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 16/24] hv_netvsc: disable NAPI before channel close Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 17/24] hv_netvsc: use RCU to fix concurrent rx and queue changes Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 18/24] hv_netvsc: change GPAD teardown order on older versions Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 19/24] hv_netvsc: common detach logic Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 20/24] hv_netvsc: Use Windows version instead of NVSP version on GPAD teardown Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 21/24] hv_netvsc: Split netvsc_revoke_buf() and netvsc_teardown_gpadl() Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 22/24] hv_netvsc: Ensure correct teardown message sequence order Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 23/24] hv_netvsc: Fix net device attach on older Windows hosts Stephen Hemminger
2018-05-14 22:32 ` [PATCH net-stable 24/24] hv_netvsc: set master device Stephen Hemminger
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