perf tools: Fix sparse CPU numbering related bugs
At present, the perf subcommands that do system-wide monitoring
(perf stat, perf record and perf top) don't work properly unless
the online cpus are numbered 0, 1, ..., N-1. These tools ask
for the number of online cpus with sysconf(_SC_NPROCESSORS_ONLN)
and then try to create events for cpus 0, 1, ..., N-1.
This creates problems for systems where the online cpus are
numbered sparsely. For example, a POWER6 system in
single-threaded mode (i.e. only running 1 hardware thread per
core) will have only even-numbered cpus online.
This fixes the problem by reading the /sys/devices/system/cpu/online
file to find out which cpus are online. The code that does that is in
tools/perf/util/cpumap.[ch], and consists of a read_cpu_map()
function that sets up a cpumap[] array and returns the number of
online cpus. If /sys/devices/system/cpu/online can't be read or
can't be parsed successfully, it falls back to using sysconf to
ask how many cpus are online and sets up an identity map in cpumap[].
The perf record, perf stat and perf top code then calls
read_cpu_map() in the system-wide monitoring case (instead of
sysconf) and uses cpumap[] to get the cpu numbers to pass to
perf_event_open.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100310093609.GA3959@brick.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-10 20:36:09 +11:00
# ifndef __PERF_CPUMAP_H
# define __PERF_CPUMAP_H
2012-01-19 14:07:23 -02:00
# include <stdio.h>
2012-09-26 12:41:14 -03:00
# include <stdbool.h>
2015-06-23 00:36:04 +02:00
# include <linux/atomic.h>
2012-01-19 14:07:23 -02:00
2014-04-07 14:55:21 -04:00
# include "perf.h"
# include "util/debug.h"
2011-01-03 17:49:48 -02:00
struct cpu_map {
2015-06-23 00:36:04 +02:00
atomic_t refcnt ;
2011-01-03 17:49:48 -02:00
int nr ;
int map [ ] ;
} ;
struct cpu_map * cpu_map__new ( const char * cpu_list ) ;
2015-10-25 15:51:17 +01:00
struct cpu_map * cpu_map__empty_new ( int nr ) ;
2011-01-03 17:49:48 -02:00
struct cpu_map * cpu_map__dummy_new ( void ) ;
2015-10-25 15:51:25 +01:00
struct cpu_map * cpu_map__new_data ( struct cpu_map_data * data ) ;
2012-09-10 15:53:50 +08:00
struct cpu_map * cpu_map__read ( FILE * file ) ;
2016-06-28 13:29:04 +02:00
size_t cpu_map__snprint ( struct cpu_map * map , char * buf , size_t size ) ;
2012-01-19 14:07:23 -02:00
size_t cpu_map__fprintf ( struct cpu_map * map , FILE * fp ) ;
2015-09-01 09:58:11 -04:00
int cpu_map__get_socket_id ( int cpu ) ;
2015-10-16 12:41:15 +02:00
int cpu_map__get_socket ( struct cpu_map * map , int idx , void * data ) ;
2015-09-01 09:58:11 -04:00
int cpu_map__get_core_id ( int cpu ) ;
2015-10-16 12:41:15 +02:00
int cpu_map__get_core ( struct cpu_map * map , int idx , void * data ) ;
2013-02-06 15:46:01 +01:00
int cpu_map__build_socket_map ( struct cpu_map * cpus , struct cpu_map * * sockp ) ;
2013-02-14 13:57:29 +01:00
int cpu_map__build_core_map ( struct cpu_map * cpus , struct cpu_map * * corep ) ;
2013-02-06 15:46:01 +01:00
2015-06-23 00:36:04 +02:00
struct cpu_map * cpu_map__get ( struct cpu_map * map ) ;
void cpu_map__put ( struct cpu_map * map ) ;
2013-02-06 15:46:01 +01:00
static inline int cpu_map__socket ( struct cpu_map * sock , int s )
{
if ( ! sock | | s > sock - > nr | | s < 0 )
return 0 ;
return sock - > map [ s ] ;
}
2012-01-19 14:07:23 -02:00
2013-02-14 13:57:29 +01:00
static inline int cpu_map__id_to_socket ( int id )
{
return id > > 16 ;
}
static inline int cpu_map__id_to_cpu ( int id )
{
return id & 0xffff ;
}
2012-09-26 12:41:14 -03:00
static inline int cpu_map__nr ( const struct cpu_map * map )
{
return map ? map - > nr : 1 ;
}
2013-05-22 17:42:38 -07:00
static inline bool cpu_map__empty ( const struct cpu_map * map )
2012-09-26 12:41:14 -03:00
{
return map ? map - > map [ 0 ] = = - 1 : true ;
}
2014-04-07 14:55:21 -04:00
int cpu__setup_cpunode_map ( void ) ;
2016-01-26 15:51:46 -03:00
int cpu__max_node ( void ) ;
int cpu__max_cpu ( void ) ;
int cpu__get_node ( int cpu ) ;
2014-04-07 14:55:21 -04:00
2015-10-16 12:41:14 +02:00
int cpu_map__build_map ( struct cpu_map * cpus , struct cpu_map * * res ,
2015-10-16 12:41:15 +02:00
int ( * f ) ( struct cpu_map * map , int cpu , void * data ) ,
void * data ) ;
2016-04-12 15:29:25 +02:00
2016-07-15 11:08:11 +01:00
int cpu_map__cpu ( struct cpu_map * cpus , int idx ) ;
2016-04-12 15:29:25 +02:00
bool cpu_map__has ( struct cpu_map * cpus , int cpu ) ;
2016-07-15 11:08:11 +01:00
int cpu_map__idx ( struct cpu_map * cpus , int cpu ) ;
perf tools: Fix sparse CPU numbering related bugs
At present, the perf subcommands that do system-wide monitoring
(perf stat, perf record and perf top) don't work properly unless
the online cpus are numbered 0, 1, ..., N-1. These tools ask
for the number of online cpus with sysconf(_SC_NPROCESSORS_ONLN)
and then try to create events for cpus 0, 1, ..., N-1.
This creates problems for systems where the online cpus are
numbered sparsely. For example, a POWER6 system in
single-threaded mode (i.e. only running 1 hardware thread per
core) will have only even-numbered cpus online.
This fixes the problem by reading the /sys/devices/system/cpu/online
file to find out which cpus are online. The code that does that is in
tools/perf/util/cpumap.[ch], and consists of a read_cpu_map()
function that sets up a cpumap[] array and returns the number of
online cpus. If /sys/devices/system/cpu/online can't be read or
can't be parsed successfully, it falls back to using sysconf to
ask how many cpus are online and sets up an identity map in cpumap[].
The perf record, perf stat and perf top code then calls
read_cpu_map() in the system-wide monitoring case (instead of
sysconf) and uses cpumap[] to get the cpu numbers to pass to
perf_event_open.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100310093609.GA3959@brick.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-10 20:36:09 +11:00
# endif /* __PERF_CPUMAP_H */