[REGRESSION v5.3] SUNRPC: Replace the queue timer with a delayed work function (7e0a0e38fcfe)

From: Jon Hunter
Date: Fri Oct 25 2019 - 03:29:02 EST


Hi Trond,

Similar to the change 431235818bc3 ("SUNRPC: Declare RPC timers as
TIMER_DEFERRABLE") I have been tracking down another suspend/NFS related
issue where again I am seeing random delays exiting suspend. The delays
can be up to a couple minutes in the worst case and this is causing a
suspend test we have to fail. For example, with this change I see ...

[ 130.599520] PM: suspend entry (deep)

[ 130.607267] Filesystems sync: 0.000 seconds

[ 130.615800] Freezing user space processes ... (elapsed 0.001 seconds) done.

[ 130.628247] OOM killer disabled.

[ 130.635382] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.

[ 130.648052] printk: Suspending console(s) (use no_console_suspend to debug)

[ 130.686015] Disabling non-boot CPUs ...

[ 130.689568] IRQ 17: no longer affine to CPU2

[ 130.693435] Entering suspend state LP1

[ 130.693489] Enabling non-boot CPUs ...

[ 130.697108] CPU1 is up

[ 130.700602] CPU2 is up

[ 130.704338] CPU3 is up

[ 130.781259] mmc1: queuing unknown CIS tuple 0x80 (50 bytes)

[ 130.789742] mmc1: queuing unknown CIS tuple 0x80 (7 bytes)

[ 130.792793] mmc1: queuing unknown CIS tuple 0x80 (7 bytes)

[ 130.820913] mmc1: queuing unknown CIS tuple 0x02 (1 bytes)

[ 131.345569] OOM killer enabled.

[ 131.352643] Restarting tasks ... done.

[ 131.365480] PM: suspend exit

[ 134.524261] asix 1-1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1

[ 243.745788] nfs: server 192.168.99.1 not responding, still trying

[ 243.745811] nfs: server 192.168.99.1 not responding, still trying

[ 243.767939] nfs: server 192.168.99.1 not responding, still trying

[ 243.778233] nfs: server 192.168.99.1 OK

[ 243.787058] nfs: server 192.168.99.1 OK

[ 243.787542] nfs: server 192.168.99.1 OK


Running a git bisect I was able to track it down to the commit referenced
in the $subject. Reverting this on top of the current mainline fixes the
problem and I no longer see these long delays.

Cheers
Jon

--
nvpublic