topic Cache in Operating System - HP-UX

Cache

Ajithnath.G — Thu, 21 Sep 2000 11:47:29 GMT

Dear Friends,

In HP UX how i can find out how much cache is there in the machine through a command ?

Thanks in advance.

regards,
ajith

Re: Cache

John Palmer — Thu, 21 Sep 2000 11:54:04 GMT

If you mean the dynamic buffer cache, have a look at this previous thread:-

http://my1.itrc.hp.com/cm/QuestionAnswer/1,1150,0xf4870559ff7cd4118fef0090279cd0f9,00.html

echo "bufpages/D" | adb /stand/vmunix /dev/kmem

seems to be the best solution where the contents of bufpages is the total of 4Kb pages.

Re: Cache

Ajithnath.G — Thu, 21 Sep 2000 12:33:35 GMT

Dear ,

I not yet tried the command u have wrote to me but wheather it will give the machines cache memeory ?

regards,
an

Re: Cache

John Palmer — Thu, 21 Sep 2000 12:44:25 GMT

An example from one of my servers:-

echo "bufpages/D" | adb /stand/vmunix /dev/kmem
bufpages:
bufpages: 13685

So the buffer cache consists currently of 13685 pages which are 4Kb each. This give a total of just under 53.5Mb which is confirmed using 'glance'.

Re: Cache

Bill Hassell — Thu, 21 Sep 2000 15:57:09 GMT

I think Ajith is asking about the hardware cache on the processor board. In this case, there is no HP-UX command although you could run the xstm or cstm diagnostic programs (the diags must be loaded from the latest SupportPlus CDROM) and see if it reports the cache size.

And unlike PC's, there are several hardware features unique to the PA-RISC architecture in addition to instruction/data cache hardware such as the TLB (Translation Lookaside Buffer) which is used to map memory pages. HP-UX can address dozens of Gbytes of RAM and with variable page sizes, efficient use of the TLB can be added to programs that use large RAM areas.

Re: Cache

Ajithnath.G — Fri, 22 Sep 2000 13:01:30 GMT

Dear All,

i was asking about the processor cache and thank you for the informations..

wish u all a nice day,

ajith