diff options
| author | Len Brown <len.brown@intel.com> | 2012-06-03 23:24:00 -0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2012-06-03 23:24:00 -0400 |
| commit | d15cf7c129fa4ec4b44c52521e49ffafb9749029 (patch) | |
| tree | 03c323fe9623f7e82400bdfabdd3711a45596a53 /tools | |
| parent | f8f5701bdaf9134b1f90e5044a82c66324d2073f (diff) | |
tools/power turbostat: fix un-intended affinity of forked program
Linux 3.4 included a modification to turbostat to
lower cross-call overhead by using scheduler affinity:
15aaa34654831e98dd76f7738b6c7f5d05a66430
(tools turbostat: reduce measurement overhead due to IPIs)
In the use-case where turbostat forks a child program,
that change had the un-intended side-effect of binding
the child to the last cpu in the system.
This change removed the binding before forking the child.
This is a back-port of a fix already included in turbostat v2.
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/power/x86/turbostat/turbostat.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c index ab2f682fd44..d5d6a3dc9ba 100644 --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c @@ -73,8 +73,8 @@ int backwards_count; char *progname; int num_cpus; -cpu_set_t *cpu_mask; -size_t cpu_mask_size; +cpu_set_t *cpu_present_set, *cpu_mask; +size_t cpu_present_setsize, cpu_mask_size; struct counters { unsigned long long tsc; /* per thread */ @@ -103,6 +103,12 @@ struct timeval tv_even; struct timeval tv_odd; struct timeval tv_delta; +int mark_cpu_present(int pkg, int core, int cpu) +{ + CPU_SET_S(cpu, cpu_present_setsize, cpu_present_set); + return 0; +} + /* * cpu_mask_init(ncpus) * @@ -118,6 +124,18 @@ void cpu_mask_init(int ncpus) } cpu_mask_size = CPU_ALLOC_SIZE(ncpus); CPU_ZERO_S(cpu_mask_size, cpu_mask); + + /* + * Allocate and initialize cpu_present_set + */ + cpu_present_set = CPU_ALLOC(ncpus); + if (cpu_present_set == NULL) { + perror("CPU_ALLOC"); + exit(3); + } + cpu_present_setsize = CPU_ALLOC_SIZE(ncpus); + CPU_ZERO_S(cpu_present_setsize, cpu_present_set); + for_all_cpus(mark_cpu_present); } void cpu_mask_uninit() @@ -125,6 +143,9 @@ void cpu_mask_uninit() CPU_FREE(cpu_mask); cpu_mask = NULL; cpu_mask_size = 0; + CPU_FREE(cpu_present_set); + cpu_present_set = NULL; + cpu_present_setsize = 0; } int cpu_migrate(int cpu) @@ -1047,6 +1068,9 @@ int fork_it(char **argv) int retval; pid_t child_pid; get_counters(cnt_even); + + /* clear affinity side-effect of get_counters() */ + sched_setaffinity(0, cpu_present_setsize, cpu_present_set); gettimeofday(&tv_even, (struct timezone *)NULL); child_pid = fork(); |