how many procs ?

[marco17]

I bought a two proc machine .
lscfg -v | grep proc
gives me

proc0 Processor
proc2 Processor

But...


lsattr -El aio0
gives me

autoconfig available STATE to be configured at system restart True
fastpath enable State of fast path True
kprocprio 39 Server PRIORITY True
maxreqs 4096 Maximum number of REQUESTS True
maxservers 40 MAXIMUM number of servers per cpu True
minservers 1 MINIMUM number of servers True

and

ps aux | grep -w aioserver | wc -l
gives me : 160

The strange thing is that i read that number of aioserver will be : number of proc x max aio servers.
So I waw expecting 80 aioservers.

And also when i launch nmon it tells me :

Version v11e for AIX53
4 - CPUs currently
4 - CPUs configured
2097 - MHz CPU clock rate PowerPC_POWER5 -Processor
64 bit -Hardware
64 bit -Kernel
Dynamic - Logical Partition
5.3.0.55 ML05 - AIX Kernel Version

So he's right ? lscfg ? or nmon and the number of aioservers ?

Marco??????

 

[MoreFeo]

Try the command smtctl
It will tell you if SMT is enabled.

If SMT is enabled, your system sees 2 virtual CPUs per physical processor, so lscfg will show 2 procs, but nmon will see 4 CPUs, that's why you will have 160 aioserver instead of 80.

 

[mrn]

Each cpu is actually 2 cpus, if you include the daughter. run pmcycles -m

Mike

"Whenever I dwell for any length of time on my own shortcomings, they gradually begin to seem mild, harmless, rather engaging little things, not at all like the staring defects in other people's characters."

 

[marco17]

you are right.

This system is SMT capable.

SMT is currently enabled.

SMT boot mode is not set.
SMT threads are bound to the same physical processor.

proc0 has 2 SMT threads.
Bind processor 0 is bound with proc0
Bind processor 1 is bound with proc0


proc2 has 2 SMT threads.
Bind processor 2 is bound with proc2
Bind processor 3 is bound with proc2

I now have to understand if i have any interest in it and if there is anythings to know about it when running oracle.

Many thanks.
Marco.

 

[MoreFeo]

I've found this pdf:

http://www-03.ibm.com/servers/aix/whitepapers/aix_support.pdf

 

[marco17]

Many thanks.
I'm going to read that carefully.


Marco.

 

[p5wizard]

Most apps (oracle among them) will benefit from SMT, expect a 30pct (figure may vary) decrease in perf if you disable it.

I'd also enable it at boot time - it is not at this time:

This system is SMT capable.

SMT is currently enabled.

[red]SMT boot mode is not set.[/red]
SMT threads are bound to the same physical processor.

Use smit smt to enable SMT at "Now and subsequent boots"



HTH,

p5wizard