diff options
author | Wen Gu <guwen@linux.alibaba.com> | 2021-11-13 10:33:35 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-08 11:04:38 +0300 |
commit | fb92e025baa73e99250b79ab64f4e088d2888993 (patch) | |
tree | 14436e3e1bb5a0fd2ff21dbd480411e6ad667645 /.gitignore | |
parent | cc447c1e14825ccf609494b48022f0e09e94cc46 (diff) | |
download | linux-fb92e025baa73e99250b79ab64f4e088d2888993.tar.xz |
net/smc: Transfer remaining wait queue entries during fallback
[ Upstream commit 2153bd1e3d3dbf6a3403572084ef6ed31c53c5f0 ]
The SMC fallback is incomplete currently. There may be some
wait queue entries remaining in smc socket->wq, which should
be removed to clcsocket->wq during the fallback.
For example, in nginx/wrk benchmark, this issue causes an
all-zeros test result:
server: nginx -g 'daemon off;'
client: smc_run wrk -c 1 -t 1 -d 5 http://11.200.15.93/index.html
Running 5s test @ http://11.200.15.93/index.html
1 threads and 1 connections
Thread Stats Avg Stdev Max ± Stdev
Latency 0.00us 0.00us 0.00us -nan%
Req/Sec 0.00 0.00 0.00 -nan%
0 requests in 5.00s, 0.00B read
Requests/sec: 0.00
Transfer/sec: 0.00B
The reason for this all-zeros result is that when wrk used SMC
to replace TCP, it added an eppoll_entry into smc socket->wq
and expected to be notified if epoll events like EPOLL_IN/
EPOLL_OUT occurred on the smc socket.
However, once a fallback occurred, wrk switches to use clcsocket.
Now it is clcsocket->wq instead of smc socket->wq which will
be woken up. The eppoll_entry remaining in smc socket->wq does
not work anymore and wrk stops the test.
This patch fixes this issue by removing remaining wait queue
entries from smc socket->wq to clcsocket->wq during the fallback.
Link: https://www.spinics.net/lists/netdev/msg779769.html
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to '.gitignore')
0 files changed, 0 insertions, 0 deletions