parse_cpumask() is too strict for oslat, in that use_current_cpuset() will
filter out all the cores that are not allowed for current process to run. This
seems to be unnecessary at least for oslat. For example, the bash process that
runs the oslat program may have a sched affinity of 0-2, however it's still
legal to have it start a oslat thread running on the cores outside 0-2 as long
as the follow up sched_setaffinity() will succeed.
numa_parse_cpustring_all() suites exactly for this case, which should already
have considered sysconf(_SC_NPROCESSORS_ONLN) limit. Use that instead.
Since at it, also remove initialization of cpu_set variable otherwise it's
leaked in previous parse_cpumask too: numa_parse_cpustring_all() will return a
newly allocated buffer already. Quotting from manual:
numa_parse_nodestring() parses a character string list of nodes into a bit
mask. The bit mask is allocated by numa_allocate_nodemask().
numa_parse_nodestring_all() is similar to numa_parse_nodestring, but can
parse all possible nodes, not only current nodeset.
Cc: John Kacur <jkacur@xxxxxxxxxx>
Cc: Daniel Wagner <dwagner@xxxxxxx>
Cc: Clark Williams <williams@xxxxxxxxxx>
Reported-by: Pradipta Kumar Sahoo <psahoo@xxxxxxxxxx>
Reported-by: Mike Stowell <mstowell@xxxxxxxxxx>
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
src/oslat/oslat.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/src/oslat/oslat.c b/src/oslat/oslat.c
index b2c5373..465a694 100644
--- a/src/oslat/oslat.c
+++ b/src/oslat/oslat.c
@@ -785,7 +785,6 @@ int main(int argc, char *argv[])
struct thread *threads;
int i, n_cores;
struct bitmask *cpu_set = NULL;
- int max_cpus = sysconf(_SC_NPROCESSORS_ONLN);
#ifdef FRC_MISSING
printf("This architecture is not yet supported. "
@@ -797,10 +796,6 @@ int main(int argc, char *argv[])
exit(1);
}
- cpu_set = numa_allocate_cpumask();
- if (!cpu_set)
- fatal("oslat: Could not allocate cpumask\n");
-
g.app_name = argv[0];
g.rtprio = 0;
g.bucket_size = BUCKET_SIZE;
@@ -817,7 +812,8 @@ int main(int argc, char *argv[])
if (!g.cpu_list)
g.cpu_list = strdup("all");
- if (parse_cpumask(g.cpu_list, max_cpus, &cpu_set) != 0)
+ cpu_set = numa_parse_cpustring_all(g.cpu_list);
+ if (!cpu_set)
fatal("oslat: parse_cpumask failed.\n");
n_cores = numa_bitmask_weight(cpu_set);
--
2.26.2
