GNOME Bugzilla – Bug 788923
Disk read / Disk write are backwards in the Processes page
Last modified: 2018-04-04 05:27:37 UTC
Disk read / Disk write are backwards in the Processes page of gnome-system-monitor. For a process that is only reading from disk it shows values under "Disk write". And for a process that is only writing to disk, it shows values under "Disk read". Running iotop or monitoring /proc/PID/io shows no such bug anywhere else. Only in gnome-system-monitor.
Hello Daniel, can you produce screenshots showing the discrepencies betweent system-monitor and iotop ?
Running gnome-system-monitor 3.26.0 on Ubuntu 17.10. Tested while downloading 700MB file with Firefox. gnome-system-monitor and "iotop -aoP " were used to measure disk writes. iotop correctly shows disk writes over 700MB, but gnome-system-monitor has similar number in "Disk read totals". During download gnome-system-monitor was reporting disk read speed, not disk write, that I suppose is mixed up too.
Created attachment 362282 [details] Disk writes in system-monitor and iotop
This bug also occurs for the same version of system monitor (3.26.0) on Manjaro Linux (Arch variant).
Created attachment 363460 [details] Screenshot comparing iotop and gnome system monitor
Created attachment 365591 [details] [review] Fix #780644 This patch fixes the order of columns vis-a-vis the enum in which the process data is stored. It seems to be fine, but someone should test it too. (First-time contributer here, please forgive -- and point out -- mistakes. Also, shouldn't the severity be upgraded to major or higher? A process monitor which shows incorrect data is worse than nothing at all -- I lost a fair amount of time trying to save my SSD from being eaten by "disk writes" which were actually disk reads.
Created attachment 365592 [details] [review] Fix bgo#780644 This patch fixes the order of columns vis-à-vis the enum in which the process data is stored. It seems to be fine, but someone should test it too. (First-time contributor, please forgive -- and point out -- mistakes.) Also, shouldn't the severity be upgraded to major or higher? A process monitor which shows incorrect data is worse than nothing at all -- I lost a fair amount of time trying to save my SSD from being eaten by "disk writes" which were actually disk reads.
Review of attachment 365592 [details] [review]: Thanks for your contribution. You seem to have no mistakes, I only found one thing to comment, namely the application.h changes are not necessary, as that is the initialization only, so it works regardless of the order of the fields.
I'm sorry I haven't fixed this until now. I once had tried to understand how the two are flipped, given that their order should be correct, but I could not find out and gave up. Your suggested fix is the easy and fast fix, let's go with that. Marking as fixed. This problem has been fixed in the unstable development version. The fix will be available in the next major software release. You may need to upgrade your Linux distribution to obtain that newer version.
*** Bug 792517 has been marked as a duplicate of this bug. ***
*** Bug 794954 has been marked as a duplicate of this bug. ***