From 3f61a12b08bd84e6cf705484c2cb9d5b891882fa Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 5 Dec 2024 20:23:05 -0800 Subject: [PATCH] perf hwmon_pmu: Use openat rather than dup to refresh directory The hwmon PMU test will make a temp directory, open the directory with O_DIRECTORY then fill it with contents. As the open is before the filling the contents the later fdopendir may reflect the initial empty state, meaning no events are seen. Change to re-open the directory, rather than dup the fd, so the latest contents are seen. Minor tweaks/additions to debug messages. Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/r/20241206042306.1055913-1-irogers@google.com Signed-off-by: Namhyung Kim --- tools/perf/util/hwmon_pmu.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/hwmon_pmu.c b/tools/perf/util/hwmon_pmu.c index e61429b38ba7b..4acb9bb19b846 100644 --- a/tools/perf/util/hwmon_pmu.c +++ b/tools/perf/util/hwmon_pmu.c @@ -258,8 +258,12 @@ static int hwmon_pmu__read_events(struct hwmon_pmu *pmu) if (pmu->pmu.sysfs_aliases_loaded) return 0; - /* Use a dup-ed fd as closedir will close it. */ - dup_fd = dup(pmu->hwmon_dir_fd); + /* + * Use a dup-ed fd as closedir will close it. Use openat so that the + * directory contents are refreshed. + */ + dup_fd = openat(pmu->hwmon_dir_fd, ".", O_DIRECTORY); + if (dup_fd == -1) return -ENOMEM; @@ -336,6 +340,9 @@ static int hwmon_pmu__read_events(struct hwmon_pmu *pmu) close(fd); } } + if (hashmap__size(&pmu->events) == 0) + pr_debug2("hwmon_pmu: %s has no events\n", pmu->pmu.name); + hashmap__for_each_entry_safe((&pmu->events), cur, tmp, bkt) { union hwmon_pmu_event_key key = { .type_and_num = cur->key, @@ -343,8 +350,8 @@ static int hwmon_pmu__read_events(struct hwmon_pmu *pmu) struct hwmon_pmu_event_value *value = cur->pvalue; if (!test_bit(HWMON_ITEM_INPUT, value->items)) { - pr_debug("hwmon_pmu: removing event '%s%d' that has no input file\n", - hwmon_type_strs[key.type], key.num); + pr_debug("hwmon_pmu: %s removing event '%s%d' that has no input file\n", + pmu->pmu.name, hwmon_type_strs[key.type], key.num); hashmap__delete(&pmu->events, key.type_and_num, &key, &value); zfree(&value->label); zfree(&value->name);