tree 218ee3f956ab10e72cfeb0fe1c9ae6731bb0e353
parent c82e61641b81b252690b1aa4efb66ff509ebd7c4
author Potin Lai <potin.lai@quantatw.com> 1661219233 +0000
committer Potin Lai <potin.lai@quantatw.com> 1661272075 +0000

healthMonitor: use MemAvailable for memory utilzation calculation

We notice the memory utilization can easily reach 95% or higher when
large files are being readed, and most memories are consumed by
filesystem as file cache.

In current memory utilizaion calculation, it calculate "total - free"
as uesd memory size, which includes buff/cache as part of used memory.

Convert method to get MemAvailable and MemTotal by parsing from
/proc/meminfo, then calculate "unavailable" memory percentage
for memory utilization.

Tested results:

root@bletchley:~# free
              total        used        free      shared  buff/cache   available
Mem:        2066620      247320       59108       34412     1760192     1713028
Swap:             0           0           0

root@bletchley:~# busctl introspect xyz.openbmc_project.HealthMon \
> /xyz/openbmc_project/sensors/utilization/Memory \
> xyz.openbmc_project.Sensor.Value
NAME                             TYPE      SIGNATURE RESULT/VALUE                             FLAGS
.MaxValue                        property  d         100                                      emits-change writable
.MinValue                        property  d         0                                        emits-change writable
.Unit                            property  s         "xyz.openbmc_project.Sensor.Value.Uni... emits-change writable
.Value                           property  d         14.9148                                  emits-change writable

Signed-off-by: Potin Lai <potin.lai@quantatw.com>
Change-Id: Ib87edb313bcfbdae1306847babc4c7a5d96766f9