Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1731371 > unrolled thread

Seemingly random performance degradation in 4.13

Back to article view | Back to linux.kernel

Contents

  Seemingly random performance degradation in 4.13 vcaputo@pengaru.com - 2017-09-13 06:40 +0200

#1731371 — Seemingly random performance degradation in 4.13

Hello,

I've been working on some graphics hacks which has me paying close
attention to frame rates.  Something I've noticed recently in the 4.13
cycle is a seemingly random loss of ~40% frame rate.  These are purely
software-rendered hacks, and I haven't spent much time trying to figure out
what is changing when the performance drops - typically the performance is
restored on a subsequent boot.

There's been talk of NUMA and scheduler related performance regressions,
and I'm wondering if that's related to what I'm observing.

Is there a fix floating around I can apply and see if it prevents
regressions from occurring?

FYI the machine in question is a 1.8Ghz core2 duo thinkpad x61s, currently
on 4.13-rc7.

If there's anything in particular that would be useful for me to capture
when running one of these tests, a specific perf incantation for example,
I'm happy to test and report the results.

Cheers,
Vito Caputo

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web