Bug 1779759

Summary: Change Latency-performance profile kernel.sched for higher performance runs
Product: Red Hat Enterprise Linux 8 Reporter: Tom Tracy <ttracy>
Component: tunedAssignee: Jaroslav Škarvada <jskarvad>
Status: CLOSED ERRATA QA Contact: Robin Hack <rhack>
Severity: high Docs Contact:
Priority: high    
Version: 8.2CC: dshaks, jeder, jskarvad, olysonek, perfbz, psklenar, rhack, thozza
Target Milestone: rcKeywords: Patch
Target Release: 8.0Flags: pm-rhel: mirror+
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: tuned-2.13.0-1.el8 Doc Type: No Doc Update
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-04-28 16:59:38 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Tom Tracy 2019-12-04 16:31:29 UTC
Description of problem:


Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1.
2.
3.

Actual results:


Expected results:


Additional info:

Comment 1 Tom Tracy 2019-12-04 17:06:54 UTC
Description of problem:

Reducing the following kernel-sched parameters produce better results. For example Oracle OLTP.

Change the following


    Kernel.sched_min_granularity_ns from 10000000 to 3000000

    Kernel.sched_wakeup_granularity_ns from 15000000 to 4000000


Version-Release number of selected component (if applicable):

tuned-2.13.0-0.1.rc1.el8.noarch

How reproducible: Every time


Steps to Reproduce:
1. Build oracle database with the changed values above
2. Run the test
3. Measure the result and compare 

Actual results:

6% gain with Oracle OLTP with 60 users with SkyLake

14-24% gain with 10 & 20 users with Oracle running on SandyBridge with Netapp

https://docs.google.com/spreadsheets/d/1Ad1Ma-UJWEPG0R_gT8BRWEyw0foobai9pTA4Sqt_R2w/edit#gid=1387255602


Expected results:


Additional info:

Just reducing the 2 values above, we see significant gains and those parameters need to be changed.

Comment 2 John Shakshober 2019-12-05 19:11:42 UTC
Need this changes based on SAP and other Linpack, Streams, IOzone, and SPECjbb runs as well.

These tunables are part of a "re-evaluate tuned profiles settings for RHEL 8.2".  
They have been used by the SAP Hana benchmarks for x86 as well as Power 9.  

Thanks
Shak

Comment 3 Ondřej Lysoněk 2019-12-09 12:15:20 UTC
Upstream pull request:
https://github.com/redhat-performance/tuned/pull/233

Comment 4 Jaroslav Škarvada 2019-12-11 13:16:40 UTC
Is this about latency-performance profile? The latency-performance profile has currently only:
kernel.sched_min_granularity_ns=10000000

There is no kernel.sched_wakeup_granularity_ns setting.

Wouldn't you mean throughput-performance profile? Or is this request also about adding kernel.sched_wakeup_granularity_ns to latency-performance profile?

Comment 5 Jaroslav Škarvada 2019-12-11 13:25:58 UTC
(In reply to Jaroslav Škarvada from comment #4)
> Is this about latency-performance profile? The latency-performance profile
> has currently only:
> kernel.sched_min_granularity_ns=10000000
> 
> There is no kernel.sched_wakeup_granularity_ns setting.
> 
> Wouldn't you mean throughput-performance profile? Or is this request also
> about adding kernel.sched_wakeup_granularity_ns to latency-performance
> profile?

Answered through IRC.

Comment 9 errata-xmlrpc 2020-04-28 16:59:38 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:1883