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NAMEpstat_getlocality(), pstat_getproclocality() — returns system-wide or per-process information of a ccNUMA system SYNOPSIS#include <sys/pstat.h> int pstat_getlocality(
struct pst_locality *buf, size_t elemsize,
size_t elemcount, int index
);
int pstat_getproclocality(
struct pst_proc_locality *buf, size_t elemsize,
size_t pid, int index
); DESCRIPTIONpstat_getlocality()
and
pstat_getproclocality()
are part of the general
pstat(2)
functionality provided to obtain information about various
system contexts.
These calls return information on different parts of a
Cache Coherent Non-Uniform Memory Architecture (ccNUMA) system.
pstat_getlocality()
returns system-wide information, while
pstat_getproclocality()
returns per-process information. A locality is one "building block"
of a ccNUMA system. If a machine has only one locality, it is
considered to be an UMA (Uniform Memory Architecture) machine. UMA
is also a synonym for Symmetric Multiprocessor (SMP). These locality building blocks are nearly identical to the
concept of the
locality domain
(or
LDOM)
as described in the
mpctl(2)
manual page. From that manual page:
A locality domain consists of a related collection of
processors, memory, and peripheral resources that
comprise a fundamental building block of the
system. All processors and peripheral devices in a
given locality domain have equal latency to the memory
contained within that locality domain.
There is only one difference between a locality and an LDOM,
and that is the concept of
interleaved memory.
Interleaved memory is a hardware-constructed region of physical memory
that is created from the memory of several locality domains. This
memory is striped together with a very fine granularity. As an
example, consider a system with four locality domains 0, 1, 2, and 3.
Let's say they all contribute the same amount of memory to the
interleave. The interleaved memory may look like this (assuming a
64-byte striping):
Memory Address Comes From
-------------- ----------
0 - 63 (bytes) LDOM 0
64 - 127 LDOM 1
128 - 191 LDOM 2
192 - 255 LDOM 3
256 - 319 LDOM 0
etc, etc Interleaved memory is a good place to put shared objects, the
kernel, and objects that could be accessed from any part of
the system. There will be at most one interleaved locality.
Some systems may not have interleaved memory. Given the four-LDOM example above, these
pstat()
calls would return five localities - one for each LDOM, and one for
interleaved memory. The reason that
mpctl(2)
does not count
interleaved memory as an LDOM is because
mpctl(2)
is used for scheduling purposes, and interleaved memory contains no
processors. Function Descriptions- pstat_getlocality()
Returns system-wide information specific to each locality. There is one instance of this context for each locality on the system.
For each locality requested, data, up to a maximum of
elemsize
bytes, are returned in the
struct pst_locality
pointed to by
buf.
The
elemcount
parameter specifies the number of
struct pst_locality
that are available at
buf
to be filled in. The
index
parameter specifies the starting index within the context
of localities. The types and field members of the
struct pst_locality
are as follows:
- pst_locality_flags_t psl_flags
Contains information about the given locality. See the
description of
pst_locality_flags_t
below for details. - int64_t psl_ldom_id
This is the LDOM id used by
mpctl(2)
to identify this locality. For the interleaved locality,
this field will be -1. - int64_t psl_physical_id
A hardware-based number that ties the locality to some
recognizable physically indexable entity. An example of
this is a cell id number. - uint64_t psl_total_pages
The total number of physical pages in this locality. - uint64_t psl_free_pages
The number of free physical pages in this locality at this moment. - uint64_t psl_cpus
The number of enabled cpus in this locality. This is irrespective
of any
processor sets
that may be in effect for those cpus.
psl_flags
is a bitfield described by the enumerated type
pst_locality_flags_t .
This field describes some of the properties of the locality.
Valid values for
pst_locality_flags_t
are the following:
- PSL_INTERLEAVED
This locality is the interleaved locality. - PSL_LOCAL
This locality is not an interleaved locality. It will map to
exactly one locality domain returned by the
mpctl(2)
system call.
PSL_LOCAL
and
PSL_INTERLEAVED
are mutually exclusive. - PSL_FLOATING
This locality does not contribute any physical memory to the
interleave.
PSL_FLOATING
can only be set if
PSL_LOCAL
is also set.
On an UMA system, there will be one locality and
PSL_LOCAL
will be set in
psl_flags. - pstat_getproclocality()
Returns information specific to a particular process' locality behavior. There is one instance of this context for each
locality for each process on the system.
For each instance requested, data, up
to a maximum of
elemsize
bytes, are returned in the
struct pst_proc_locality
pointed to by
buf.
At most one instance (locality) is returned for each call to
pstat_getproclocality().
The
pid
parameter specifies
the process id of the process for which locality
information is to be returned. A
pid
of zero
indicates that locality information for the currently
executing process should be returned. The
index
parameter
specifies the starting index within the context of localities. The types and field members of the
struct pst_proc_locality
are as follows:
- int64_t ppl_ldom_id
This is the LDOM id used by
mpctl(2)
to identify this locality. For the interleaved locality,
this field will be -1. - uint64_t ppl_rss_total
The total number of resident pages for this process in this locality. - uint64_t ppl_rss_shared
The number of shared resident pages for this process in this locality. - uint64_t ppl_rss_private
The number of private resident pages for this process in this locality. - uint64_t ppl_rss_weighted
The number of resident pages for this process in this locality, weighted
by the number of processes sharing each page. Private pages count as one
page, and shared pages count as the page divided by the number of processes
sharing that page.
NotesThese functions only return the wide (64 bit) versions of
their associated structures. In order for narrow (32 bit)
applications to use these interfaces, the flag
-D_PSTAT64
must be used at compile time. These interfaces are available for
narrow applications written in standard C and extended ANSI, and
for all wide applications. RETURN VALUEpstat_getlocality()
and
pstat_getproclocality()
return the following values:
- n
Successful completion.
n
is the number of instances returned in
buf . - -1
Failure.
errno
is set to indicate the error.
ERRORSUpon failure,
errno
is set to one of the following values.
- [EFAULT]
buf
points to an invalid address. - [EINVAL]
elemsize
is less than or equal to zero, or
elemsize
is larger than
the size of the associated data structure. - [EINVAL]
index
is negative. - [ESRCH]
for pstat_getproclocality(), the requested pid could not be found.
EXAMPLES/*
* This program returns system-wide and per-process memory
* locality information. To compile the 32-bit version,
* use -D_PSTAT64. The 64-bit version does not need any
* special compiler flags.
*/
#include <unistd.h>
#include <stdio.h>
#include <sys/param.h>
#include <sys/pstat.h>
#include <sys/errno.h>
#define BURST ((size_t)3)
#define STRSZ 80
unsigned long pgsize;
void pid_locinfo ( pid_t pid );
void sys_locinfo ( void );
void pages_to_str ( uint64_t pages, char *str );
void
usage ( int argc, char **argv )
{
fprintf ( stderr, "Usage: %s [-p pid]\n", argv[0] );
fprintf ( stderr, "This program prints out per locality " );
fprintf ( stderr, "memory usage.\nIf 'pid' is supplied, " );
fprintf ( stderr, "information on that process is\n" );
fprintf ( stderr, "returned in addition to system-wide " );
fprintf ( stderr, "information.\n\n" );
exit(1);
}
/*
* Verify arguments, call sys_locinfo(), and call pid_locinfo()
* if desired.
*/
int
main ( int argc, char **argv )
{
pid_t pid = (pid_t) 0;
if ( (argc == 2) || (argc > 3) ||
((argc == 3) && (strncmp(argv[1], "-p", 2))) ) {
usage(argc, argv);
}
if ( argc == 3 ) {
pid = atoi(argv[2]);
if (pid < 0) {
/* note that pid 0 is "this process" */
usage(argc, argv);
}
}
/* Get the size of a page for later calculations */
pgsize = sysconf ( _SC_PAGE_SIZE );
sys_locinfo();
if ( argc == 3 ) {
pid_locinfo ( pid );
}
return 0;
}
/*
* Display the system-wide memory usage per locality.
*/
void
sys_locinfo ( void )
{
int i; /* index within pstl[] */
int count; /* the actual number of pstl structures */
int idx = 0; /* index within the context of localities */
struct pst_locality pstl[BURST];
char total_str[STRSZ], free_str[STRSZ], used_str[STRSZ];
uint64_t total=0, free=0;
printf ( " --- System wide locality info: --- \n" );
printf ( "%6s%6s%7s%6s%10s%10s%10s\n",
"index", "ldom", "physid", "type",
"total", "free", "used" );
/* Get a maximum of BURST pst_locality structures */
count = pstat_getlocality ( pstl, sizeof(struct pst_locality),
BURST, idx );
while ( count > 0 ) {
for ( i=0 ; i<count ; i++ ) {
/* Keep running totals for later */
total += pstl[i].psl_total_pages;
free += pstl[i].psl_free_pages;
/* Convert integers into strings */
pages_to_str ( pstl[i].psl_total_pages, total_str );
pages_to_str ( pstl[i].psl_free_pages, free_str );
pages_to_str ( (pstl[i].psl_total_pages -
pstl[i].psl_free_pages), used_str );
printf ( "%6d%6lld%7lld%6s%10s%10s%10s\n",
(idx+i),
pstl[i].psl_ldom_id,
pstl[i].psl_physical_id,
((pstl[i].psl_flags & PSL_INTERLEAVED) ?
"ILV":"CLM"),
total_str, free_str, used_str );
}
idx += count;
/*
* Get (at most) the next BURST pst_locality
* structures, starting at idx
*/
count = pstat_getlocality ( pstl,
sizeof(struct pst_locality),
BURST, idx );
}
if ( count < 0 ) {
perror ( "pstat_getlocality" );
exit(1);
}
if ( idx == 1 ) {
/* Don't print totals if there's one locality */
printf ( "\n" );
return;
}
/* Convert integer totals into strings */
pages_to_str ( total, total_str );
pages_to_str ( free, free_str );
pages_to_str ( total-free, used_str );
/* Print totals */
printf ( "%6s%6s%7s%6s%10s%10s%10s\n",
"", "", "", "", "-----", "-----", "-----" );
printf ( "%6s%6s%7s%6s%10s%10s%10s\n\n",
"", "", "", "", total_str, free_str, used_str );
}
/*
* Given a pid, display its per-locality physical memory usage.
*/
void
pid_locinfo ( pid_t pid )
{
int count, i=0;
struct pst_proc_locality ppl;
char total_str[STRSZ], shared_str[STRSZ];
char private_str[STRSZ], weighted_str[STRSZ];
uint64_t total=0, shared=0, private=0, weighted=0;
/*
* With this interface, information on only one locality
* can be returned at a time. This will get the first:
*/
count = pstat_getproclocality ( &ppl,
sizeof(struct pst_proc_locality), pid, i );
printf ( " --- Per-process locality info for pid %d: ---\n",
pid );
printf ( "%6s%10s%10s%10s%10s\n",
"idx", "total", "shared", "private", "weighted" );
while ( count == 1 ) {
total += ppl.ppl_rss_total;
shared += ppl.ppl_rss_shared;
private += ppl.ppl_rss_private;
weighted += ppl.ppl_rss_weighted;
pages_to_str ( ppl.ppl_rss_total, total_str );
pages_to_str ( ppl.ppl_rss_shared, shared_str );
pages_to_str ( ppl.ppl_rss_private, private_str );
pages_to_str ( ppl.ppl_rss_weighted, weighted_str );
printf ( "%6d%10s%10s%10s%10s\n",
i, total_str, shared_str,
private_str, weighted_str );
i++;
count = pstat_getproclocality ( &ppl,
sizeof(struct pst_proc_locality),
pid, i );
}
if ( count < 0 ) {
if ( errno == ESRCH ) {
fprintf ( stderr, "Process %d not found\n", pid );
exit(1);
}
perror ( "pstat_getproclocality" );
exit(1);
}
if ( i == 1 ) {
/* Don't print totals if there's one locality */
printf ( "\n" );
return;
}
pages_to_str ( total, total_str );
pages_to_str ( shared, shared_str );
pages_to_str ( private, private_str );
pages_to_str ( weighted, weighted_str );
printf ( "%6s%10s%10s%10s%10s\n",
"", "-----", "-----", "-----", "-----" );
printf ( "%6s%10s%10s%10s%10s\n\n",
"", total_str, shared_str,
private_str, weighted_str );
}
/*
* Given a quantity of memory in pages, fill str with a
* human-readable string representing that amount.
*/
void
pages_to_str ( uint64_t pages, char *str )
{
uint64_t kpg = pages*(pgsize/1024L);
uint64_t mpg = kpg/1024L;
uint64_t gpg = mpg/1024L;
if ( gpg > 10 ) {
sprintf ( str, "%lluG", gpg );
} else if ( mpg > 10 ) {
sprintf ( str, "%lluM", mpg );
} else if ( kpg > 1 ) {
sprintf ( str, "%lluK", kpg );
} else {
sprintf ( str, "%llu", pages );
}
} AUTHORThe
pstat
routines were developed by Hewlett-Packard Company. |
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