F23: System Load: Application memory calculation

[Terry Barnaby]

Is the KDE/Plasma "System Load" calculation of application used memory 
correct ?

Currently on my system the KDE "System Load" panel widget shows 11.3G of 
memory used by applications in a 24G memory system. ksysguard is the same.

/proc/meminfo shows:

MemTotal:       24689476 kB
MemFree:         1081276 kB
MemAvailable:   20106752 kB
Buffers:         4722180 kB
Cached:          7071252 kB
SwapCached:         4156 kB
Active:          8374976 kB
Inactive:        6882576 kB
Active(anon):    2623148 kB
Inactive(anon):  1005372 kB
Active(file):    5751828 kB
Inactive(file):  5877204 kB
Unevictable:          32 kB
Mlocked:              32 kB

The "top" program states 4G used which matches the /proc/meminfo. So the 
11G seems incorrect...

Terry

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[Reindl Harald]

Am 15.06.2016 um 14:08 schrieb Terry Barnaby:
>  Is the KDE/Plasma "System Load" calculation of application
> used memory
>  correct ?
>
>  Currently on my system the KDE "System Load" panel widget shows 11.3G of
>  memory used by applications in a 24G memory system. ksysguard is the same.
>
>  /proc/meminfo shows:
>
>  MemTotal:       24689476 kB
>  MemFree:         1081276 kB
>  MemAvailable:   20106752 kB
>  Buffers:         4722180 kB
>  Cached:          7071252 kB
>  SwapCached:         4156 kB
>  Active:          8374976 kB
>  Inactive:        6882576 kB
>  Active(anon):    2623148 kB
>  Inactive(anon):  1005372 kB
>  Active(file):    5751828 kB
>  Inactive(file):  5877204 kB
>  Unevictable:          32 kB
>  Mlocked:              32 kB
>
>  The "top" program states 4G used which matches the /proc/meminfo. So the
>  11G seems incorrect... 
guess what the 4 GB + cached gives....

hence the systemload widget splits the memory in different colors to 
distinct between cache and resident memory used by applications

cached is also memory  and it's used so nothing wrong besides that "how 
much memory i am using" is a terrible complex question with a ton of 
different answers

[Terry Barnaby]

On 15/06/16 14:02, Reindl Harald wrote:
>  Am 15.06.2016 um 14:08 schrieb Terry Barnaby:
> > Is the KDE/Plasma "System Load" calculation of application used memory
> > correct ?
> >
> > Currently on my system the KDE "System Load" panel widget shows 11.3G of
> > memory used by applications in a 24G memory system. ksysguard is the 
> > same.
> >
> > /proc/meminfo shows:
> >
> > MemTotal:       24689476 kB
> > MemFree:         1081276 kB
> > MemAvailable:   20106752 kB
> > Buffers:         4722180 kB
> > Cached:          7071252 kB
> > SwapCached:         4156 kB
> > Active:          8374976 kB
> > Inactive:        6882576 kB
> > Active(anon):    2623148 kB
> > Inactive(anon):  1005372 kB
> > Active(file):    5751828 kB
> > Inactive(file):  5877204 kB
> > Unevictable:          32 kB
> > Mlocked:              32 kB
> >
> > The "top" program states 4G used which matches the /proc/meminfo. So the
> > 11G seems incorrect...
>
>  guess what the 4 GB + cached gives....
>
>  hence the systemload widget splits the memory in different colors to 
>  distinct between cache and resident memory used by applications
>
>  cached is also memory  and it's used so nothing wrong besides that 
>  "how much memory i am using" is a terrible complex question with a ton 
>  of different answers
>
>
>
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>  kde(a)lists.fedoraproject.org
>  https://lists.fedoraproject.org/admin/lists/[e-mail] 
Sorry that
doesn't make sense. If the SystemLoad widget shows 
Application usage as "Application + cache" then it is not distinguishing 
between cache and resident memory used by applications ...

I would have thought that it should show separately: "Application, 
cache, buffers" rather than: "Application + cache, cache, buffers".

[Reindl Harald]

Am 15.06.2016 um 17:14 schrieb Terry Barnaby:
>  On 15/06/16 14:02, Reindl Harald wrote:
> >> The "top" program states 4G used which matches the /proc/meminfo. So
> the
> >> 11G seems incorrect...
> >
> > guess what the 4 GB + cached gives....
> >
> > hence the systemload widget splits the memory in different colors to
> > distinct between cache and resident memory used by applications
> >
> > cached is also memory  and it's used so nothing wrong besides that
> > "how much memory i am using" is a terrible complex question with a ton
> > of different answers
> >
>  Sorry that doesn't make sense. If the SystemLoad widget shows
>  Application usage as "Application + cache" then it is not distinguishing
>  between cache and resident memory used by applications ...
>
>  I would have thought that it should show separately: "Application,
>  cache, buffers" rather than: "Application + cache, cache, buffers" 
first fix your qouting and exclude footers to begin with
IT DOES show it seperatly with different colors

frankly the colors for resident, cache and buffers are even configureable

[Terry Barnaby]

On 16/06/16 00:07, Reindl Harald wrote:
>  Am 15.06.2016 um 17:14 schrieb Terry Barnaby:
> > On 15/06/16 14:02, Reindl Harald wrote:
> >>> The "top" program states 4G used which matches the /proc/meminfo.
> So
> >>> the
> >>> 11G seems incorrect...
> >>
> >> guess what the 4 GB + cached gives....
> >>
> >> hence the systemload widget splits the memory in different colors to
> >> distinct between cache and resident memory used by applications
> >>
> >> cached is also memory  and it's used so nothing wrong besides that
> >> "how much memory i am using" is a terrible complex question with a ton
> >> of different answers
> >>
> > Sorry that doesn't make sense. If the SystemLoad widget shows
> > Application usage as "Application + cache" then it is not distinguishing
> > between cache and resident memory used by applications ...
> >
> > I would have thought that it should show separately: "Application,
> > cache, buffers" rather than: "Application + cache, cache, buffers"
>
>  first fix your qouting and exclude footers to begin with
>  IT DOES show it seperatly with different colors
>
>  frankly the colors for resident, cache and buffers are even configureable 
Sorry I don't understand or you don't understand what I am saying.

I am saying that the KDE "System Load" widget and the ksysguard 
application show that the amount of memory used by applications is much 
higher than it should be on this system. Other tools show it as about 4G 
while the KDE tools state 11G.

I think I have found the cause of the problem. The algorithms used in 
ksysguard-5.6.4/ksysguardd/Linux/Memory.c are outdated being based on 
older kernels. Newer Linux kernels include in /proc/meminfo the 
parameter "MemAvailable" which should be used to calculate the amount of 
memory that is actually available for use after application needed 
memory is considered. This was added as the calculation of memory being 
effectively used for caching was difficult for user level programs to 
calculate (Not all cache memory is reported in the meminfo's "Cached"
parameter and some of the Cache is fixed memory anyway (Shared memory 
segments etc)).

The likely reason I am seeing a high application memory usage is because 
this system is being used as a file server using NFS/SMB etc. In this 
case (and others) there is memory effectively being used as cache that 
is not reported in the "cached" parameter. There is some memory from 
"SReclaimable" for example. The old style KDE memory usage
calculations are ignoring these extra bits and thus end up displaying
a very high and wrong value for Application memory usage (11G instead of 
4G).

I will file a bug report. I guess this is best done at bugs.kde.org ?

Terry

[Reindl Harald]

Am 16.06.2016 um 08:59 schrieb Terry Barnaby:
>  On 16/06/16 00:07, Reindl Harald wrote:
> >> I would have thought that it should show separately: "Application,
> >> cache, buffers" rather than: "Application + cache, cache,
> buffers"
> >
> > first fix your qouting and exclude footers to begin with
> > IT DOES show it seperatly with different colors
> >
> > frankly the colors for resident, cache and buffers are even configureable
>
>  Sorry I don't understand or you don't understand what I am saying 

see screenshot, green = cache