From e52966c084f9d9ea12be2ac7df801d610d4a19a5 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Thu, 8 Nov 2012 22:38:05 -0500 Subject: [PATCH] tools/power turbostat: prevent infinite loop on migration error path Turbostat assumed if it can't migrate to a CPU, then the CPU must have gone off-line and turbostat should re-initialize with the new topology. But if turbostat can not migrate because it is restricted by a cpuset, then it will fail to migrate even after re-initialization, resulting in an infinite loop. Spit out a warning when we can't migrate and endure only 2 re-initialize cycles in a row before giving up and exiting. Signed-off-by: Len Brown --- tools/power/x86/turbostat/turbostat.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c index 3c063a00f3bf..77e76b11382f 100644 --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c @@ -656,8 +656,10 @@ int get_counters(struct thread_data *t, struct core_data *c, struct pkg_data *p) { int cpu = t->cpu_id; - if (cpu_migrate(cpu)) + if (cpu_migrate(cpu)) { + fprintf(stderr, "Could not migrate to CPU %d\n", cpu); return -1; + } t->tsc = rdtsc(); /* we are running on local CPU of interest */ @@ -1088,15 +1090,22 @@ int mark_cpu_present(int cpu) void turbostat_loop() { int retval; + int restarted = 0; restart: + restarted++; + retval = for_all_cpus(get_counters, EVEN_COUNTERS); if (retval < -1) { exit(retval); } else if (retval == -1) { + if (restarted > 1) { + exit(retval); + } re_initialize(); goto restart; } + restarted = 0; gettimeofday(&tv_even, (struct timezone *)NULL); while (1) { -- 2.34.1