D11558: Don't show cache memory in systemloadviewer bars

[David Edmundson]

davidedmundson added a comment.


  We're at an impasse then.
  
  I do like and respect having your feedback, but I'm not particularly swayed.  
It leaves this one super tiny summary applet showing more "detailed/noisy" 
information than the full on ksysguard application, which  doesn't make sense.  
We can be pretty sure there's no-one currently using it for that, based on the 
fact that by default it's currently the same colour as the regular memory so 
impossible to see.
  
  Can someone else from Plasma make a decision either way.

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D11558: Don't show cache memory in systemloadviewer bars

[Henrik Fehlauer]

rkflx added a comment.


  In D11558#231516 , @davidedmundson 
wrote:
  
  > I'm not sure we're talking about the same place. This is the little 
overview applet, systemloadviewer
  >
  > F5762570: Screenshot_20180322_115217.png 

  
  
  Yup, that's exactly the thing I'm talking about. At this point I don't care 
that much about the other options, but it would be annoying if the applet lost 
that feature. I felt this might concern a lot of users using this, so I spoke 
up. I don't want to block improvements, but maybe we can find a compromise 
here. Removing features which have been there for a long time is always a bad 
message to send when one of our goals is polishing.

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D11558: Don't show cache memory in systemloadviewer bars

[David Edmundson]

davidedmundson added a comment.


  > It's a power user tool anyway,
  
  I'm not sure we're talking about the same place. This is the little overview 
applet, systemloadviewer
  
  F5762570: Screenshot_20180322_115217.png 

  
  KSysguard is the power tool. 
  Even that doesn't show it by default, but it's available if you choose to add 
custom sensors. I'm not intending on changing that.

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D11558: Don't show cache memory in systemloadviewer bars

[Henrik Fehlauer]

rkflx added a comment.


  In a sense the cache tells me about aggregated memory pressure from the past 
(because the cache will only slowly fill up again after it was squeezed), and 
the unused memory is a metrics showing the current memory pressure.
  
  I find it useful, and apparently when it was first introduced in KDE and 
later ported to Plasma it was deemed useful. It's a power user tool anyway, 
please don't tell users to go back to `xosview` (which won't work on Wayland).
  
  I see where you are coming from, though. Maybe you can make this transparent 
by default, and anyone liking the feature could turn on the colour again?

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D11558: Don't show cache memory in systemloadviewer bars

[David Edmundson]

davidedmundson added a comment.


  Unless you know how much of that cache was actually read back, you have 
absolutely no knowledge of whether the cache was utilised properly or not. 
  In your example seeing the cache value stay "good" is giving you the same 
result as seeing the free memory stay "good" just arguably with the effect 
lingering ever so slightly longer.

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D11558: Don't show cache memory in systemloadviewer bars

[Henrik Fehlauer]

rkflx added a comment.


  In D11558#231153 , @davidedmundson 
wrote:
  
  > > Quickly seeing the difference between "free" and "cached" can be quite 
useful.
  >
  > Useful for what?
  
  
  For a start, there's a problem with a system (and thus performance) if cache 
usage is always very low. "Unused" memory does not help in this case. Seeing 
this value staying in a "good" state helps to confirm that despite large memory 
hogs coming and going the cache is utilized optimally. If not, I might add more 
memory or change the system configuration (e.g. ban Electron apps ;) to improve 
cache utilization. If I would only see "free" memory, I would not be able to 
evaluate this.

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D11558: Don't show cache memory in systemloadviewer bars

[David Edmundson]

davidedmundson added a comment.


  > Quickly seeing the difference between "free" and "cached" can be quite 
useful.
  
  Useful for what?

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D11558: Don't show cache memory in systemloadviewer bars

[Henrik Fehlauer]

rkflx added a comment.


  > It's a completely useless value to know vs how much memory is free.
  
  FWIW, I find it's a useful information to assess the state of a system: It 
grows with time after a reboot, and it shows nicely how memory intensive 
processes eventually take a toll on the cache until they are closed and I'm 
left with lots of free memory but only little cache. Quickly seeing the 
difference between "free" and "cached" can be quite useful.
  
  IMO it would be enough to adapt the colours a bit (and possibly improve the 
tooltip).

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REVISION DETAIL
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D11558: Don't show cache memory in systemloadviewer bars

[David Edmundson]

davidedmundson created this revision.
davidedmundson added a reviewer: Plasma.
Restricted Application added a project: Plasma.
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davidedmundson requested review of this revision.

REVISION SUMMARY
  It's a completely useless value to know vs how much memory is free.
  It's problematic because the bar is inconsistent with the tooltip, and
  by default the system load viewer chooses a colour very similar to the
  application used memory.
  
  BUG: 391918

TEST PLAN
  Ran it
  (there's some unrelated bugs/warnings in this applet that need fixing)
  Bar showed a sensible value that matched tooltip, rather than 
  looking 100% full all the time

REPOSITORY
  R114 Plasma Addons

BRANCH
  master

REVISION DETAIL
  https://phabricator.kde.org/D11558

AFFECTED FILES
  applets/systemloadviewer/package/contents/config/main.xml
  applets/systemloadviewer/package/contents/ui/ColorSettings.qml
  applets/systemloadviewer/package/contents/ui/SystemLoadViewer.qml

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