| Message ID | 20231129060211.1890454-3-irogers@google.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | BPF |
| Headers | show |
| Series | Clean up libperf cpumap's empty function | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On 29/11/2023 06:01, Ian Rogers wrote: > Rename perf_cpu_map__default_new to perf_cpu_map__new_online_cpus to > better indicate what the implementation does. Read the online CPUs > from /sys/devices/system/cpu/online first before using sysconf as > sysconf can't accurately configure holes in the CPU map. If sysconf is > used, warn when the configured and online processors disagree. > > When reading from a file, if the read doesn't yield a CPU map then > return an empty map rather than the default online. This avoids > recursion but also better yields being able to detect failures. > > Add more comments. > > Signed-off-by: Ian Rogers <irogers@google.com> Reviewed-by: James Clark <james.clark@arm.com> > --- > tools/lib/perf/cpumap.c | 59 +++++++++++++++++----------- > tools/lib/perf/include/perf/cpumap.h | 15 ++++++- > tools/lib/perf/libperf.map | 2 +- > tools/lib/perf/tests/test-cpumap.c | 2 +- > 4 files changed, 51 insertions(+), 27 deletions(-) > > diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c > index 2bd6aba3d8c9..463ca8b37d45 100644 > --- a/tools/lib/perf/cpumap.c > +++ b/tools/lib/perf/cpumap.c > @@ -9,6 +9,7 @@ > #include <unistd.h> > #include <ctype.h> > #include <limits.h> > +#include "internal.h" > > void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus) > { > @@ -66,15 +67,21 @@ void perf_cpu_map__put(struct perf_cpu_map *map) > } > } > > -static struct perf_cpu_map *cpu_map__default_new(void) > +static struct perf_cpu_map *cpu_map__new_sysconf(void) > { > struct perf_cpu_map *cpus; > - int nr_cpus; > + int nr_cpus, nr_cpus_conf; > > nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); > if (nr_cpus < 0) > return NULL; > > + nr_cpus_conf = sysconf(_SC_NPROCESSORS_CONF); > + if (nr_cpus != nr_cpus_conf) { > + pr_warning("Number of online CPUs (%d) differs from the number configured (%d) the CPU map will only cover the first %d CPUs.", > + nr_cpus, nr_cpus_conf, nr_cpus); > + } > + > cpus = perf_cpu_map__alloc(nr_cpus); > if (cpus != NULL) { > int i; > @@ -86,9 +93,27 @@ static struct perf_cpu_map *cpu_map__default_new(void) > return cpus; > } > > -struct perf_cpu_map *perf_cpu_map__default_new(void) > +static struct perf_cpu_map *cpu_map__new_syfs_online(void) > { > - return cpu_map__default_new(); > + struct perf_cpu_map *cpus = NULL; > + FILE *onlnf; > + > + onlnf = fopen("/sys/devices/system/cpu/online", "r"); > + if (onlnf) { > + cpus = perf_cpu_map__read(onlnf); > + fclose(onlnf); > + } > + return cpus; > +} > + > +struct perf_cpu_map *perf_cpu_map__new_online_cpus(void) > +{ > + struct perf_cpu_map *cpus = cpu_map__new_syfs_online(); > + > + if (cpus) > + return cpus; > + > + return cpu_map__new_sysconf(); > } > > > @@ -180,27 +205,11 @@ struct perf_cpu_map *perf_cpu_map__read(FILE *file) > > if (nr_cpus > 0) > cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); > - else > - cpus = cpu_map__default_new(); > out_free_tmp: > free(tmp_cpus); > return cpus; > } > > -static struct perf_cpu_map *cpu_map__read_all_cpu_map(void) > -{ > - struct perf_cpu_map *cpus = NULL; > - FILE *onlnf; > - > - onlnf = fopen("/sys/devices/system/cpu/online", "r"); > - if (!onlnf) > - return cpu_map__default_new(); > - > - cpus = perf_cpu_map__read(onlnf); > - fclose(onlnf); > - return cpus; > -} > - > struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) > { > struct perf_cpu_map *cpus = NULL; > @@ -211,7 +220,7 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) > int max_entries = 0; > > if (!cpu_list) > - return cpu_map__read_all_cpu_map(); > + return perf_cpu_map__new_online_cpus(); > > /* > * must handle the case of empty cpumap to cover > @@ -268,9 +277,11 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) > > if (nr_cpus > 0) > cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); > - else if (*cpu_list != '\0') > - cpus = cpu_map__default_new(); > - else > + else if (*cpu_list != '\0') { > + pr_warning("Unexpected characters at end of cpu list ('%s'), using online CPUs.", > + cpu_list); > + cpus = perf_cpu_map__new_online_cpus(); > + } else > cpus = perf_cpu_map__new_any_cpu(); > invalid: > free(tmp_cpus); > diff --git a/tools/lib/perf/include/perf/cpumap.h b/tools/lib/perf/include/perf/cpumap.h > index d0bf218ada11..b24bd8b8f34e 100644 > --- a/tools/lib/perf/include/perf/cpumap.h > +++ b/tools/lib/perf/include/perf/cpumap.h > @@ -22,7 +22,20 @@ struct perf_cpu_map; > * perf_cpu_map__new_any_cpu - a map with a singular "any CPU"/dummy -1 value. > */ > LIBPERF_API struct perf_cpu_map *perf_cpu_map__new_any_cpu(void); > -LIBPERF_API struct perf_cpu_map *perf_cpu_map__default_new(void); > +/** > + * perf_cpu_map__new_online_cpus - a map read from > + * /sys/devices/system/cpu/online if > + * available. If reading wasn't possible a map > + * is created using the online processors > + * assuming the first 'n' processors are all > + * online. > + */ > +LIBPERF_API struct perf_cpu_map *perf_cpu_map__new_online_cpus(void); > +/** > + * perf_cpu_map__new - create a map from the given cpu_list such as "0-7". If no > + * cpu_list argument is provided then > + * perf_cpu_map__new_online_cpus is returned. > + */ > LIBPERF_API struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list); > LIBPERF_API struct perf_cpu_map *perf_cpu_map__read(FILE *file); > LIBPERF_API struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map); > diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map > index a8ff64baea3e..8a71f841498e 100644 > --- a/tools/lib/perf/libperf.map > +++ b/tools/lib/perf/libperf.map > @@ -2,7 +2,7 @@ LIBPERF_0.0.1 { > global: > libperf_init; > perf_cpu_map__new_any_cpu; > - perf_cpu_map__default_new; > + perf_cpu_map__new_online_cpus; > perf_cpu_map__get; > perf_cpu_map__put; > perf_cpu_map__new; > diff --git a/tools/lib/perf/tests/test-cpumap.c b/tools/lib/perf/tests/test-cpumap.c > index 2c359bdb951e..c998b1dae863 100644 > --- a/tools/lib/perf/tests/test-cpumap.c > +++ b/tools/lib/perf/tests/test-cpumap.c > @@ -29,7 +29,7 @@ int test_cpumap(int argc, char **argv) > perf_cpu_map__put(cpus); > perf_cpu_map__put(cpus); > > - cpus = perf_cpu_map__default_new(); > + cpus = perf_cpu_map__new_online_cpus(); > if (!cpus) > return -1; >
Em Tue, Nov 28, 2023 at 10:01:59PM -0800, Ian Rogers escreveu: > Rename perf_cpu_map__default_new to perf_cpu_map__new_online_cpus to > better indicate what the implementation does. Read the online CPUs > from /sys/devices/system/cpu/online first before using sysconf as > sysconf can't accurately configure holes in the CPU map. If sysconf is > used, warn when the configured and online processors disagree. > > When reading from a file, if the read doesn't yield a CPU map then > return an empty map rather than the default online. This avoids > recursion but also better yields being able to detect failures. > > Add more comments. > > Signed-off-by: Ian Rogers <irogers@google.com> > --- > tools/lib/perf/cpumap.c | 59 +++++++++++++++++----------- > tools/lib/perf/include/perf/cpumap.h | 15 ++++++- > tools/lib/perf/libperf.map | 2 +- > tools/lib/perf/tests/test-cpumap.c | 2 +- > 4 files changed, 51 insertions(+), 27 deletions(-) > > diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c > index 2bd6aba3d8c9..463ca8b37d45 100644 > --- a/tools/lib/perf/cpumap.c > +++ b/tools/lib/perf/cpumap.c > @@ -9,6 +9,7 @@ > #include <unistd.h> > #include <ctype.h> > #include <limits.h> > +#include "internal.h" > > void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus) > { > @@ -66,15 +67,21 @@ void perf_cpu_map__put(struct perf_cpu_map *map) > } > } > > -static struct perf_cpu_map *cpu_map__default_new(void) > +static struct perf_cpu_map *cpu_map__new_sysconf(void) > { > struct perf_cpu_map *cpus; > - int nr_cpus; > + int nr_cpus, nr_cpus_conf; > > nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); > if (nr_cpus < 0) > return NULL; > > + nr_cpus_conf = sysconf(_SC_NPROCESSORS_CONF); > + if (nr_cpus != nr_cpus_conf) { > + pr_warning("Number of online CPUs (%d) differs from the number configured (%d) the CPU map will only cover the first %d CPUs.", > + nr_cpus, nr_cpus_conf, nr_cpus); > + } > + > cpus = perf_cpu_map__alloc(nr_cpus); > if (cpus != NULL) { > int i; > @@ -86,9 +93,27 @@ static struct perf_cpu_map *cpu_map__default_new(void) > return cpus; > } > > -struct perf_cpu_map *perf_cpu_map__default_new(void) > +static struct perf_cpu_map *cpu_map__new_syfs_online(void) I'm renaming this to cpu_map__new_sysfs_online(), ok? - Arnaldo > { > - return cpu_map__default_new(); > + struct perf_cpu_map *cpus = NULL; > + FILE *onlnf; > + > + onlnf = fopen("/sys/devices/system/cpu/online", "r"); > + if (onlnf) { > + cpus = perf_cpu_map__read(onlnf); > + fclose(onlnf); > + } > + return cpus; > +} > + > +struct perf_cpu_map *perf_cpu_map__new_online_cpus(void) > +{ > + struct perf_cpu_map *cpus = cpu_map__new_syfs_online(); > + > + if (cpus) > + return cpus; > + > + return cpu_map__new_sysconf(); > } > > > @@ -180,27 +205,11 @@ struct perf_cpu_map *perf_cpu_map__read(FILE *file) > > if (nr_cpus > 0) > cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); > - else > - cpus = cpu_map__default_new(); > out_free_tmp: > free(tmp_cpus); > return cpus; > } > > -static struct perf_cpu_map *cpu_map__read_all_cpu_map(void) > -{ > - struct perf_cpu_map *cpus = NULL; > - FILE *onlnf; > - > - onlnf = fopen("/sys/devices/system/cpu/online", "r"); > - if (!onlnf) > - return cpu_map__default_new(); > - > - cpus = perf_cpu_map__read(onlnf); > - fclose(onlnf); > - return cpus; > -} > - > struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) > { > struct perf_cpu_map *cpus = NULL; > @@ -211,7 +220,7 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) > int max_entries = 0; > > if (!cpu_list) > - return cpu_map__read_all_cpu_map(); > + return perf_cpu_map__new_online_cpus(); > > /* > * must handle the case of empty cpumap to cover > @@ -268,9 +277,11 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) > > if (nr_cpus > 0) > cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); > - else if (*cpu_list != '\0') > - cpus = cpu_map__default_new(); > - else > + else if (*cpu_list != '\0') { > + pr_warning("Unexpected characters at end of cpu list ('%s'), using online CPUs.", > + cpu_list); > + cpus = perf_cpu_map__new_online_cpus(); > + } else > cpus = perf_cpu_map__new_any_cpu(); > invalid: > free(tmp_cpus); > diff --git a/tools/lib/perf/include/perf/cpumap.h b/tools/lib/perf/include/perf/cpumap.h > index d0bf218ada11..b24bd8b8f34e 100644 > --- a/tools/lib/perf/include/perf/cpumap.h > +++ b/tools/lib/perf/include/perf/cpumap.h > @@ -22,7 +22,20 @@ struct perf_cpu_map; > * perf_cpu_map__new_any_cpu - a map with a singular "any CPU"/dummy -1 value. > */ > LIBPERF_API struct perf_cpu_map *perf_cpu_map__new_any_cpu(void); > -LIBPERF_API struct perf_cpu_map *perf_cpu_map__default_new(void); > +/** > + * perf_cpu_map__new_online_cpus - a map read from > + * /sys/devices/system/cpu/online if > + * available. If reading wasn't possible a map > + * is created using the online processors > + * assuming the first 'n' processors are all > + * online. > + */ > +LIBPERF_API struct perf_cpu_map *perf_cpu_map__new_online_cpus(void); > +/** > + * perf_cpu_map__new - create a map from the given cpu_list such as "0-7". If no > + * cpu_list argument is provided then > + * perf_cpu_map__new_online_cpus is returned. > + */ > LIBPERF_API struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list); > LIBPERF_API struct perf_cpu_map *perf_cpu_map__read(FILE *file); > LIBPERF_API struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map); > diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map > index a8ff64baea3e..8a71f841498e 100644 > --- a/tools/lib/perf/libperf.map > +++ b/tools/lib/perf/libperf.map > @@ -2,7 +2,7 @@ LIBPERF_0.0.1 { > global: > libperf_init; > perf_cpu_map__new_any_cpu; > - perf_cpu_map__default_new; > + perf_cpu_map__new_online_cpus; > perf_cpu_map__get; > perf_cpu_map__put; > perf_cpu_map__new; > diff --git a/tools/lib/perf/tests/test-cpumap.c b/tools/lib/perf/tests/test-cpumap.c > index 2c359bdb951e..c998b1dae863 100644 > --- a/tools/lib/perf/tests/test-cpumap.c > +++ b/tools/lib/perf/tests/test-cpumap.c > @@ -29,7 +29,7 @@ int test_cpumap(int argc, char **argv) > perf_cpu_map__put(cpus); > perf_cpu_map__put(cpus); > > - cpus = perf_cpu_map__default_new(); > + cpus = perf_cpu_map__new_online_cpus(); > if (!cpus) > return -1; > > -- > 2.43.0.rc1.413.gea7ed67945-goog >
On Tue, Dec 12, 2023 at 9:39 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > Em Tue, Nov 28, 2023 at 10:01:59PM -0800, Ian Rogers escreveu: > > Rename perf_cpu_map__default_new to perf_cpu_map__new_online_cpus to > > better indicate what the implementation does. Read the online CPUs > > from /sys/devices/system/cpu/online first before using sysconf as > > sysconf can't accurately configure holes in the CPU map. If sysconf is > > used, warn when the configured and online processors disagree. > > > > When reading from a file, if the read doesn't yield a CPU map then > > return an empty map rather than the default online. This avoids > > recursion but also better yields being able to detect failures. > > > > Add more comments. > > > > Signed-off-by: Ian Rogers <irogers@google.com> > > --- > > tools/lib/perf/cpumap.c | 59 +++++++++++++++++----------- > > tools/lib/perf/include/perf/cpumap.h | 15 ++++++- > > tools/lib/perf/libperf.map | 2 +- > > tools/lib/perf/tests/test-cpumap.c | 2 +- > > 4 files changed, 51 insertions(+), 27 deletions(-) > > > > diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c > > index 2bd6aba3d8c9..463ca8b37d45 100644 > > --- a/tools/lib/perf/cpumap.c > > +++ b/tools/lib/perf/cpumap.c > > @@ -9,6 +9,7 @@ > > #include <unistd.h> > > #include <ctype.h> > > #include <limits.h> > > +#include "internal.h" > > > > void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus) > > { > > @@ -66,15 +67,21 @@ void perf_cpu_map__put(struct perf_cpu_map *map) > > } > > } > > > > -static struct perf_cpu_map *cpu_map__default_new(void) > > +static struct perf_cpu_map *cpu_map__new_sysconf(void) > > { > > struct perf_cpu_map *cpus; > > - int nr_cpus; > > + int nr_cpus, nr_cpus_conf; > > > > nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); > > if (nr_cpus < 0) > > return NULL; > > > > + nr_cpus_conf = sysconf(_SC_NPROCESSORS_CONF); > > + if (nr_cpus != nr_cpus_conf) { > > + pr_warning("Number of online CPUs (%d) differs from the number configured (%d) the CPU map will only cover the first %d CPUs.", > > + nr_cpus, nr_cpus_conf, nr_cpus); > > + } > > + > > cpus = perf_cpu_map__alloc(nr_cpus); > > if (cpus != NULL) { > > int i; > > @@ -86,9 +93,27 @@ static struct perf_cpu_map *cpu_map__default_new(void) > > return cpus; > > } > > > > -struct perf_cpu_map *perf_cpu_map__default_new(void) > > +static struct perf_cpu_map *cpu_map__new_syfs_online(void) > > I'm renaming this to cpu_map__new_sysfs_online(), ok? Yep, typo. Thanks! Ian > - Arnaldo > > > { > > - return cpu_map__default_new(); > > + struct perf_cpu_map *cpus = NULL; > > + FILE *onlnf; > > + > > + onlnf = fopen("/sys/devices/system/cpu/online", "r"); > > + if (onlnf) { > > + cpus = perf_cpu_map__read(onlnf); > > + fclose(onlnf); > > + } > > + return cpus; > > +} > > + > > +struct perf_cpu_map *perf_cpu_map__new_online_cpus(void) > > +{ > > + struct perf_cpu_map *cpus = cpu_map__new_syfs_online(); > > + > > + if (cpus) > > + return cpus; > > + > > + return cpu_map__new_sysconf(); > > } > > > > > > @@ -180,27 +205,11 @@ struct perf_cpu_map *perf_cpu_map__read(FILE *file) > > > > if (nr_cpus > 0) > > cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); > > - else > > - cpus = cpu_map__default_new(); > > out_free_tmp: > > free(tmp_cpus); > > return cpus; > > } > > > > -static struct perf_cpu_map *cpu_map__read_all_cpu_map(void) > > -{ > > - struct perf_cpu_map *cpus = NULL; > > - FILE *onlnf; > > - > > - onlnf = fopen("/sys/devices/system/cpu/online", "r"); > > - if (!onlnf) > > - return cpu_map__default_new(); > > - > > - cpus = perf_cpu_map__read(onlnf); > > - fclose(onlnf); > > - return cpus; > > -} > > - > > struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) > > { > > struct perf_cpu_map *cpus = NULL; > > @@ -211,7 +220,7 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) > > int max_entries = 0; > > > > if (!cpu_list) > > - return cpu_map__read_all_cpu_map(); > > + return perf_cpu_map__new_online_cpus(); > > > > /* > > * must handle the case of empty cpumap to cover > > @@ -268,9 +277,11 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) > > > > if (nr_cpus > 0) > > cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); > > - else if (*cpu_list != '\0') > > - cpus = cpu_map__default_new(); > > - else > > + else if (*cpu_list != '\0') { > > + pr_warning("Unexpected characters at end of cpu list ('%s'), using online CPUs.", > > + cpu_list); > > + cpus = perf_cpu_map__new_online_cpus(); > > + } else > > cpus = perf_cpu_map__new_any_cpu(); > > invalid: > > free(tmp_cpus); > > diff --git a/tools/lib/perf/include/perf/cpumap.h b/tools/lib/perf/include/perf/cpumap.h > > index d0bf218ada11..b24bd8b8f34e 100644 > > --- a/tools/lib/perf/include/perf/cpumap.h > > +++ b/tools/lib/perf/include/perf/cpumap.h > > @@ -22,7 +22,20 @@ struct perf_cpu_map; > > * perf_cpu_map__new_any_cpu - a map with a singular "any CPU"/dummy -1 value. > > */ > > LIBPERF_API struct perf_cpu_map *perf_cpu_map__new_any_cpu(void); > > -LIBPERF_API struct perf_cpu_map *perf_cpu_map__default_new(void); > > +/** > > + * perf_cpu_map__new_online_cpus - a map read from > > + * /sys/devices/system/cpu/online if > > + * available. If reading wasn't possible a map > > + * is created using the online processors > > + * assuming the first 'n' processors are all > > + * online. > > + */ > > +LIBPERF_API struct perf_cpu_map *perf_cpu_map__new_online_cpus(void); > > +/** > > + * perf_cpu_map__new - create a map from the given cpu_list such as "0-7". If no > > + * cpu_list argument is provided then > > + * perf_cpu_map__new_online_cpus is returned. > > + */ > > LIBPERF_API struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list); > > LIBPERF_API struct perf_cpu_map *perf_cpu_map__read(FILE *file); > > LIBPERF_API struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map); > > diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map > > index a8ff64baea3e..8a71f841498e 100644 > > --- a/tools/lib/perf/libperf.map > > +++ b/tools/lib/perf/libperf.map > > @@ -2,7 +2,7 @@ LIBPERF_0.0.1 { > > global: > > libperf_init; > > perf_cpu_map__new_any_cpu; > > - perf_cpu_map__default_new; > > + perf_cpu_map__new_online_cpus; > > perf_cpu_map__get; > > perf_cpu_map__put; > > perf_cpu_map__new; > > diff --git a/tools/lib/perf/tests/test-cpumap.c b/tools/lib/perf/tests/test-cpumap.c > > index 2c359bdb951e..c998b1dae863 100644 > > --- a/tools/lib/perf/tests/test-cpumap.c > > +++ b/tools/lib/perf/tests/test-cpumap.c > > @@ -29,7 +29,7 @@ int test_cpumap(int argc, char **argv) > > perf_cpu_map__put(cpus); > > perf_cpu_map__put(cpus); > > > > - cpus = perf_cpu_map__default_new(); > > + cpus = perf_cpu_map__new_online_cpus(); > > if (!cpus) > > return -1; > > > > -- > > 2.43.0.rc1.413.gea7ed67945-goog > > > > -- > > - Arnaldo
diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c index 2bd6aba3d8c9..463ca8b37d45 100644 --- a/tools/lib/perf/cpumap.c +++ b/tools/lib/perf/cpumap.c @@ -9,6 +9,7 @@ #include <unistd.h> #include <ctype.h> #include <limits.h> +#include "internal.h" void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus) { @@ -66,15 +67,21 @@ void perf_cpu_map__put(struct perf_cpu_map *map) } } -static struct perf_cpu_map *cpu_map__default_new(void) +static struct perf_cpu_map *cpu_map__new_sysconf(void) { struct perf_cpu_map *cpus; - int nr_cpus; + int nr_cpus, nr_cpus_conf; nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); if (nr_cpus < 0) return NULL; + nr_cpus_conf = sysconf(_SC_NPROCESSORS_CONF); + if (nr_cpus != nr_cpus_conf) { + pr_warning("Number of online CPUs (%d) differs from the number configured (%d) the CPU map will only cover the first %d CPUs.", + nr_cpus, nr_cpus_conf, nr_cpus); + } + cpus = perf_cpu_map__alloc(nr_cpus); if (cpus != NULL) { int i; @@ -86,9 +93,27 @@ static struct perf_cpu_map *cpu_map__default_new(void) return cpus; } -struct perf_cpu_map *perf_cpu_map__default_new(void) +static struct perf_cpu_map *cpu_map__new_syfs_online(void) { - return cpu_map__default_new(); + struct perf_cpu_map *cpus = NULL; + FILE *onlnf; + + onlnf = fopen("/sys/devices/system/cpu/online", "r"); + if (onlnf) { + cpus = perf_cpu_map__read(onlnf); + fclose(onlnf); + } + return cpus; +} + +struct perf_cpu_map *perf_cpu_map__new_online_cpus(void) +{ + struct perf_cpu_map *cpus = cpu_map__new_syfs_online(); + + if (cpus) + return cpus; + + return cpu_map__new_sysconf(); } @@ -180,27 +205,11 @@ struct perf_cpu_map *perf_cpu_map__read(FILE *file) if (nr_cpus > 0) cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); - else - cpus = cpu_map__default_new(); out_free_tmp: free(tmp_cpus); return cpus; } -static struct perf_cpu_map *cpu_map__read_all_cpu_map(void) -{ - struct perf_cpu_map *cpus = NULL; - FILE *onlnf; - - onlnf = fopen("/sys/devices/system/cpu/online", "r"); - if (!onlnf) - return cpu_map__default_new(); - - cpus = perf_cpu_map__read(onlnf); - fclose(onlnf); - return cpus; -} - struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) { struct perf_cpu_map *cpus = NULL; @@ -211,7 +220,7 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) int max_entries = 0; if (!cpu_list) - return cpu_map__read_all_cpu_map(); + return perf_cpu_map__new_online_cpus(); /* * must handle the case of empty cpumap to cover @@ -268,9 +277,11 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) if (nr_cpus > 0) cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); - else if (*cpu_list != '\0') - cpus = cpu_map__default_new(); - else + else if (*cpu_list != '\0') { + pr_warning("Unexpected characters at end of cpu list ('%s'), using online CPUs.", + cpu_list); + cpus = perf_cpu_map__new_online_cpus(); + } else cpus = perf_cpu_map__new_any_cpu(); invalid: free(tmp_cpus); diff --git a/tools/lib/perf/include/perf/cpumap.h b/tools/lib/perf/include/perf/cpumap.h index d0bf218ada11..b24bd8b8f34e 100644 --- a/tools/lib/perf/include/perf/cpumap.h +++ b/tools/lib/perf/include/perf/cpumap.h @@ -22,7 +22,20 @@ struct perf_cpu_map; * perf_cpu_map__new_any_cpu - a map with a singular "any CPU"/dummy -1 value. */ LIBPERF_API struct perf_cpu_map *perf_cpu_map__new_any_cpu(void); -LIBPERF_API struct perf_cpu_map *perf_cpu_map__default_new(void); +/** + * perf_cpu_map__new_online_cpus - a map read from + * /sys/devices/system/cpu/online if + * available. If reading wasn't possible a map + * is created using the online processors + * assuming the first 'n' processors are all + * online. + */ +LIBPERF_API struct perf_cpu_map *perf_cpu_map__new_online_cpus(void); +/** + * perf_cpu_map__new - create a map from the given cpu_list such as "0-7". If no + * cpu_list argument is provided then + * perf_cpu_map__new_online_cpus is returned. + */ LIBPERF_API struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list); LIBPERF_API struct perf_cpu_map *perf_cpu_map__read(FILE *file); LIBPERF_API struct perf_cpu_map *perf_cpu_map__get(struct perf_cpu_map *map); diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map index a8ff64baea3e..8a71f841498e 100644 --- a/tools/lib/perf/libperf.map +++ b/tools/lib/perf/libperf.map @@ -2,7 +2,7 @@ LIBPERF_0.0.1 { global: libperf_init; perf_cpu_map__new_any_cpu; - perf_cpu_map__default_new; + perf_cpu_map__new_online_cpus; perf_cpu_map__get; perf_cpu_map__put; perf_cpu_map__new; diff --git a/tools/lib/perf/tests/test-cpumap.c b/tools/lib/perf/tests/test-cpumap.c index 2c359bdb951e..c998b1dae863 100644 --- a/tools/lib/perf/tests/test-cpumap.c +++ b/tools/lib/perf/tests/test-cpumap.c @@ -29,7 +29,7 @@ int test_cpumap(int argc, char **argv) perf_cpu_map__put(cpus); perf_cpu_map__put(cpus); - cpus = perf_cpu_map__default_new(); + cpus = perf_cpu_map__new_online_cpus(); if (!cpus) return -1;
Rename perf_cpu_map__default_new to perf_cpu_map__new_online_cpus to better indicate what the implementation does. Read the online CPUs from /sys/devices/system/cpu/online first before using sysconf as sysconf can't accurately configure holes in the CPU map. If sysconf is used, warn when the configured and online processors disagree. When reading from a file, if the read doesn't yield a CPU map then return an empty map rather than the default online. This avoids recursion but also better yields being able to detect failures. Add more comments. Signed-off-by: Ian Rogers <irogers@google.com> --- tools/lib/perf/cpumap.c | 59 +++++++++++++++++----------- tools/lib/perf/include/perf/cpumap.h | 15 ++++++- tools/lib/perf/libperf.map | 2 +- tools/lib/perf/tests/test-cpumap.c | 2 +- 4 files changed, 51 insertions(+), 27 deletions(-)