linux/include
Jeff Layton 18c64378ad sunrpc: add info about xprt queue times to svc_xprt_dequeue tracepoint
I've been looking at a problem where we see increased RPC timeouts in
clients when the nfs_layout_flexfiles dataserver_timeo value is tuned
very low (6s). This is necessary to ensure quick failover to a different
mirror if a server goes down, but it causes a lot more major RPC timeouts.

Ultimately, the problem is server-side however. It's sometimes doesn't
respond to connection attempts. My theory is that the interrupt handler
runs when a connection comes in, the xprt ends up being enqueued, but it
takes a significant amount of time for the nfsd thread to pick it up.

Currently, the svc_xprt_dequeue tracepoint displays "wakeup-us". This is
the time between the wake_up() call, and the thread dequeueing the xprt.
If no thread was woken, or the thread ended up picking up a different
xprt than intended, then this value won't tell us how long the xprt was
waiting.

Add a new xpt_qtime field to struct svc_xprt and set it in
svc_xprt_enqueue(). When the dequeue tracepoint fires, also store the
time that the xprt sat on the queue in total. Display it as "qtime-us".

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-05-11 19:48:26 -04:00
..
acpi gcc-15: acpi: sprinkle random '__nonstring' crumbles around 2025-04-20 11:57:54 -07:00
asm-generic RISC-V Patches for the 6.15 Merge Window, Part 1 2025-04-04 09:49:17 -07:00
clocksource
crypto crypto: ahash - Disable request chaining 2025-04-12 09:33:09 +08:00
cxl cxl: Fix devm host device for CXL fwctl initialization 2025-04-18 09:33:04 -07:00
drm Short summary of fixes pull: 2025-05-09 08:52:24 +10:00
dt-bindings Char/Misc/IIO driver updates for 6.15-rc1 2025-04-01 11:26:08 -07:00
hyperv
keys
kunit kunit: Spelling s/slowm/slow/ 2025-04-08 14:57:24 -06:00
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linux sunrpc: add info about xprt queue times to svc_xprt_dequeue tracepoint 2025-05-11 19:48:26 -04:00
math-emu
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net net: export a helper for adding up queue stats 2025-05-08 11:56:12 +02:00
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rdma RDMA/mlx5: Fix compilation warning when USER_ACCESS isn't set 2025-04-07 15:14:34 -03:00
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sound ASoC: Fixes for v6.15 2025-05-01 10:22:20 +02:00
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trace sunrpc: add info about xprt queue times to svc_xprt_dequeue tracepoint 2025-05-11 19:48:26 -04:00
uapi bpf: Clarify handling of mark and tstamp by redirect_peer 2025-05-07 18:16:33 -07:00
ufs scsi: ufs: Introduce quirk to extend PA_HIBERN8TIME for UFS devices 2025-04-11 22:13:00 -04:00
vdso vdso: Address variable shadowing in macros 2025-04-10 11:07:10 +02:00
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