You're confusing
object types with index types.
PU is an object type, like Core, Socket, ... "logical
processor" is a generic name for cores when there's no
SMT, hardware threads when there's SMT/Hyperthreading, ...
PU is basically the smallest thing that can run a software
thread.
"P#" is just the way you're numbering object, it works for
PU and for other object types.
Any object of any type can be identified through a unique
logical index, and possibly non-unique physical index.
We don't often use the name "logical processor" because
it's indeed confusing. "Processing Unit" is less
confusing, that's why it's the official name for the
smallest objects in hwloc.
Brice
Le 01/08/2011 15:04, Gabriele Fatigati a écrit :
Hi Brice,
you said:
"PU
P#0" means "PU object with physical index 0".
"P#" prefix means "physical index".
But
from the hwloc manual, page 58:
HWLOC_OBJ_PU: Processing Unit, or (Logical)
Processor..
but it is in conflict with what you said :(
2011/8/1 Brice Goglin
<Brice.Goglin@inria.fr>
"PU
P#0" means "PU object with physical index
0".
"P#" prefix means "physical index".
"L#" prefix means "logical index" (the one
you want to use in get_obj_by_type).
Use -l or -p to switch from one to the
other in lstopo.
Brice
Le 01/08/2011 14:47, Gabriele Fatigati a
écrit :
Hi Brice,
so, if I inderstand well, PU P#
numbers are not the same
specified as HWLOC_OBJ_PU flag?
2011/8/1
Brice Goglin
<Brice.Goglin@inria.fr>
Le
01/08/2011 12:16, Gabriele
Fatigati a écrit :
> Hi,
>
> reading a hwloc-v1.2-a4
manual, on page 15, i look
an example
> with 4-socket 2-core
machine with hyperthreading.
>
> Core id's are not
exclusive as said before.
PU's id are exclusive but
> not physically
sequential (I suppose)
>
> PU P#0 is in socket P#0
on Core P#0. PU P#1 is in
another socket!
These indexes are "physical
indexes" (that's the default
in the
graphical lstopo output). But
we may want to make that
clearer in the doc.
Brice
--
Ing. Gabriele Fatigati
Parallel programmer
CINECA Systems & Tecnologies
Department
Supercomputing Group
Via Magnanelli 6/3, Casalecchio di
Reno (BO) Italy
www.cineca.it
Tel: +39 051
6171722
g.fatigati [AT]
cineca.it
--
Ing. Gabriele Fatigati
Parallel programmer
CINECA Systems & Tecnologies Department
Supercomputing Group
Via Magnanelli 6/3, Casalecchio di Reno (BO)
Italy
www.cineca.it
Tel: +39 051 6171722
g.fatigati [AT]
cineca.it