[LU-5545] a lot of warnings like ptlrpc_at_adj_net_latency() Reported service time 7 > total measured time 0 Created: 26/Aug/14  Updated: 27/Apr/15  Resolved: 06/Nov/14

Status: Resolved
Project: Lustre
Component/s: None
Affects Version/s: None
Fix Version/s: Lustre 2.7.0, Lustre 2.5.4

Type: Bug Priority: Minor
Reporter: Liang Zhen (Inactive) Assignee: Liang Zhen (Inactive)
Resolution: Fixed Votes: 0
Labels: None

Severity: 3
Rank (Obsolete): 15448

 Description   

when we enable message dropping on routers, and run a simple MPI program to repeat fstat and fchmod, I saw a lot of warnings like this in log:

Lustre: 17660:0:(client.c:304:ptlrpc_at_adj_net_latency()) Reported service time 7 > total measured time 0
Lustre: 17663:0:(client.c:304:ptlrpc_at_adj_net_latency()) Reported service time 7 > total measured time 0

they may be harmless, but it's better to fix them.



 Comments   
Comment by Chris Horn [ 28/Aug/14 ]

When client re-sends a request, the server will drop it if it is already in progress. Client then is measuring the service time from the sent time of the resend, while the server will report service time of original request. This may be the cause of the disparity.

Comment by Li Wei (Inactive) [ 29/Aug/14 ]

Chris, yes, that's exactly what I saw.

Comment by Liang Zhen (Inactive) [ 23/Sep/14 ]

Thanks Chris, patch is here: http://review.whamcloud.com/12018

Comment by Liang Zhen (Inactive) [ 06/Nov/14 ]

patch landed

Comment by Gerrit Updater [ 25/Nov/14 ]

Jian Yu (jian.yu@intel.com) uploaded a new patch: http://review.whamcloud.com/12855
Subject: LU-5545 ptlrpc: false alarm in AT network latency measuring
Project: fs/lustre-release
Branch: b2_5
Current Patch Set: 1
Commit: 8a9ff75abe59667c30b76de56f7250de74b47105

Comment by Gerrit Updater [ 04/Dec/14 ]

Oleg Drokin (oleg.drokin@intel.com) merged in patch http://review.whamcloud.com/12855/
Subject: LU-5545 ptlrpc: false alarm in AT network latency measuring
Project: fs/lustre-release
Branch: b2_5
Current Patch Set:
Commit: 73800aa81baeeb55038c1849e90631588a930981

Generated at Sat Feb 10 01:52:24 UTC 2024 using Jira 9.4.14#940014-sha1:734e6822bbf0d45eff9af51f82432957f73aa32c.