[SERVER-16572] Add counter for calls to sched_yield in WiredTiger Created: 17/Dec/14  Updated: 15/Jan/15  Resolved: 02/Jan/15

Status: Closed
Project: Core Server
Component/s: Diagnostics, Performance, Storage
Affects Version/s: None
Fix Version/s: 2.8.0-rc5

Type: Improvement Priority: Major - P3
Reporter: Bruce Lucas (Inactive) Assignee: Susan LoVerso
Resolution: Done Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Related
is related to SERVER-16269 WiredTiger blocks queries and updates... Closed
Backwards Compatibility: Fully Compatible
Participants:

 Description   

It appears that calls to sched_yield can be associated with performance issues; see for example this ticket. So it could be useful if the performance metrics included a counter for calls to sched_yield.



 Comments   
Comment by Eliot Horowitz (Inactive) [ 21/Dec/14 ]

I don't think is going to add anything. The variably in cpu spin times and scheduling is going to market this incredibly erratic and noisy. And it could easily be a perf hit. Time would be useful but even more expensive.

Comment by Charlie Page [ 18/Dec/14 ]

If these stats are tied into mongtop, etc this strategy needs to consider how the stats are reported on long waits (i.e. would this cause a wait not to even be seen until it's completed?)

Generated at Thu Feb 08 03:41:31 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.