Discrepancy Between Glance and Top Mem Usage Output?

[Chin Jin Kiat]

Hi,

I presume that the "real" value of the top output should be similiar to that of the "user" figure in Glance - both being the total allocated physical memory process? If my understanding is right, I am seeing discrepancy in the figure:

Top:
Memory: 62484K (54056K) real, 153136K (130060K) virtual, 98808K free

Glance:
Total VM : 149.5mb Sys Mem : 23.2mb User Mem: 113.3mb Phys Mem: 256.0mb
Active VM: 129.4mb Buf Cache: 23.0mb Free Mem: 96.4mb

How is this about?

Thanks in advance.

[S.K. Chan]

Well , you can't really do a one-to-one comparisoan between top and glance because both are getting their info from a different source. Top gets the current system status from /dev/kmem and that's it. Glance on the other hand pulls some of its data from /dev/kmem, but additionally a kernel interface is written to retrieve performance
information from the time the daemon has been running. Glance shows what is happening over the time the midaemon has been running, rather
than what the system shows at the moment. It also shows more detail on a per-process basis than top.

[U.SivaKumar_2]

hi,
Top reports instantaneous values where as the
glance plus give you a statistical values for
a period of time from which it has started to
analyse the system.
So it is natural to see the difference of values between their reports.
regards,
U.SivaKumar