Bug 460017 - Memory column is blank for all processes
Summary: Memory column is blank for all processes
Status: RESOLVED UPSTREAM
Alias: None
Product: plasma-systemmonitor
Classification: Applications
Component: general (other bugs)
Version First Reported In: 5.25.5
Platform: Neon Linux
: NOR normal
Target Milestone: ---
Assignee: KSysGuard Developers
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2022-10-05 17:49 UTC by Riccardo Robecchi
Modified: 2022-11-29 17:49 UTC (History)
3 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:

Attachments
Screenshot of the issue (60.86 KB, image/png)
2022-10-05 17:49 UTC, Riccardo Robecchi 		Details
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Description Riccardo Robecchi 2022-10-05 17:49:55 UTC 
Created attachment 152604 [details]
Screenshot of the issue

SUMMARY
After updating to the Linux 6.0 kernel, the memory column is blank and shows nothing for all processes, irrespective of their owner.

STEPS TO REPRODUCE
1. Open System Monitor

OBSERVED RESULT
The memory column is blank.

EXPECTED RESULT
Memory usage is correctly reported.

SOFTWARE/OS VERSIONS
Linux: KDE neon 
KDE Plasma Version: 5.25.5
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6

ADDITIONAL INFORMATION
This bug does not occur in any other monitoring software, including KSysGuard; it appears to be specific to System Monitor.
Comment 1 Riccardo Robecchi 2022-10-24 22:06:53 UTC 
The bug is still present in version 5.26.0.
Comment 2 Riccardo Robecchi 2022-11-24 12:05:06 UTC 
Still an issue as of 5.26.3 with Frameworks 5.100.0. Is there any way I can help find the cause of this and help fix it?
Comment 3 Arjen Hiemstra 2022-11-24 14:00:33 UTC 
I'm running kernel 6.0.8 at this point and have a working memory column. The memory column works by reading the information of `/proc/$PID/smaps_rollup`. Can you check the presence and permissions of those files on your system? For example using `ls -l /proc/$(pidof plasmashell)/`.
Comment 4 Riccardo Robecchi 2022-11-24 14:49:08 UTC 
Thank you for your reply, Arjen. When using 'ls -l /proc/$(pidof plasmashell)/' I see that all files are owned by my user. I have just tried installing kernel 6.0.9 on a VM and the issue appears there, too. For some reason, though, the smaps_rollup shows 0 kB on all fields (whereas the values appear correct using pre-6.0 kernel versions). Could this be a bug in the kernel I am using then?
Comment 5 Arjen Hiemstra 2022-11-24 15:15:03 UTC 
That sounds like it. For comparison, this is smaps_rollup from my current plasmashell process:

Rss:              324172 kB
Pss:              215660 kB
Pss_Dirty:        182048 kB
Pss_Anon:         181628 kB
Pss_File:          33612 kB
Pss_Shmem:           420 kB
Shared_Clean:     121772 kB
Shared_Dirty:        208 kB
Private_Clean:     20240 kB
Private_Dirty:    181952 kB
Referenced:       324172 kB
Anonymous:        181628 kB
LazyFree:              0 kB
AnonHugePages:     22528 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:      4096 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB

The important entry there being "PSS" which is the value we use for the memory column.
Comment 6 Nate Graham 2022-11-29 17:45:29 UTC 
Cool, can you file a kernel bug at https://bugzilla.kernel.org/?
Comment 7 Riccardo Robecchi 2022-11-29 17:49:24 UTC 
(In reply to Nate Graham from comment #6)
> Cool, can you file a kernel bug at https://bugzilla.kernel.org/?

I've filed one at Xanmod's bug tracker: https://github.com/xanmod/linux/issues/321