linux-stable/net/smc
Wen Gu 2153bd1e3d net/smc: Transfer remaining wait queue entries during fallback
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>
2021-11-15 13:27:02 +00:00
..
af_smc.c net/smc: Transfer remaining wait queue entries during fallback 2021-11-15 13:27:02 +00:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile net/smc: Introduce tracepoint for fallback 2021-11-01 13:39:14 +00:00
smc.h net/smc: extend LLC layer for SMC-Rv2 2021-10-16 14:58:13 +01:00
smc_cdc.c net/smc: improved fix wait on already cleared link 2021-10-08 17:00:16 +01:00
smc_cdc.h net/smc: pre-fetch send buffer outside of send_lock 2020-05-30 18:12:25 -07:00
smc_clc.c net/smc: add v2 format of CLC decline message 2021-10-16 14:58:13 +01:00
smc_clc.h net/smc: add v2 format of CLC decline message 2021-10-16 14:58:13 +01:00
smc_close.c net/smc: check variable before dereferencing in smc_close.c 2020-09-16 17:30:16 -07:00
smc_close.h net/smc: remove close abort worker 2019-10-22 11:23:44 -07:00
smc_core.c net/smc: Introduce tracepoint for smcr link down 2021-11-01 13:39:14 +00:00
smc_core.h net/smc: extend LLC layer for SMC-Rv2 2021-10-16 14:58:13 +01:00
smc_diag.c net/smc: Introduce SMCR get link command 2020-12-01 17:56:13 -08:00
smc_ib.c net/smc: stop links when their GID is removed 2021-10-16 14:58:13 +01:00
smc_ib.h net/smc: retrieve v2 gid from IB device 2021-10-16 14:58:13 +01:00
smc_ism.c net/smc: keep static copy of system EID 2021-09-14 12:49:10 +01:00
smc_ism.h net/smc: keep static copy of system EID 2021-09-14 12:49:10 +01:00
smc_llc.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-10-28 10:43:58 -07:00
smc_llc.h net/smc: extend LLC layer for SMC-Rv2 2021-10-16 14:58:13 +01:00
smc_netlink.c net/smc: add generic netlink support for system EID 2021-09-14 12:49:10 +01:00
smc_netlink.h net/smc: add support for user defined EIDs 2021-09-14 12:49:10 +01:00
smc_netns.h net/smc: introduce list of pnetids for Ethernet devices 2020-09-28 15:19:03 -07:00
smc_pnet.c net/smc: retrieve v2 gid from IB device 2021-10-16 14:58:13 +01:00
smc_pnet.h net/smc: determine proposed ISM devices 2020-09-28 15:19:03 -07:00
smc_rx.c net/smc: Introduce tracepoints for tx and rx msg 2021-11-01 13:39:14 +00:00
smc_rx.h
smc_stats.c net/smc: Fix ENODATA tests in smc_nl_get_fback_stats() 2021-06-21 12:16:58 -07:00
smc_stats.h net/smc: Make SMC statistics network namespace aware 2021-06-16 12:54:02 -07:00
smc_tracepoint.c net/smc: Introduce tracepoint for smcr link down 2021-11-01 13:39:14 +00:00
smc_tracepoint.h net/smc: Print function name in smcr_link_down tracepoint 2021-11-05 10:14:38 +00:00
smc_tx.c net/smc: Introduce tracepoints for tx and rx msg 2021-11-01 13:39:14 +00:00
smc_tx.h
smc_wr.c net/smc: extend LLC layer for SMC-Rv2 2021-10-16 14:58:13 +01:00
smc_wr.h net/smc: extend LLC layer for SMC-Rv2 2021-10-16 14:58:13 +01:00