[PATCH v1 28/48] perf kwork: Silence -Wshorten-64-to-32 warnings

From: Ian Rogers
Date: Tue Apr 01 2025 - 14:31:47 EST


The clang warning -Wshorten-64-to-32 can be useful to catch
inadvertent truncation. In some instances this truncation can lead to
changing the sign of a result, for example, truncation to return an
int to fit a sort routine. Silence the warning by making the implicit
truncation explicit.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/builtin-kwork.c | 11 +++++------
tools/perf/util/bpf_kwork_top.c | 2 +-
2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-kwork.c b/tools/perf/builtin-kwork.c
index c41a68d073de..cc5488cb98e4 100644
--- a/tools/perf/builtin-kwork.c
+++ b/tools/perf/builtin-kwork.c
@@ -1574,8 +1574,7 @@ static void top_print_per_cpu_load(struct perf_kwork *kwork)
load = stat->cpus_runtime[i].load;
if (test_bit(i, stat->all_cpus_bitmap) && total) {
load_ratio = load * 10000 / total;
- load_width = PRINT_CPU_USAGE_HIST_WIDTH *
- load_ratio / 10000;
+ load_width = (int)(PRINT_CPU_USAGE_HIST_WIDTH * load_ratio / 10000);

printf("%%Cpu%-*d[%.*s%.*s %*.*f%%]\n",
PRINT_CPU_WIDTH, i,
@@ -1595,7 +1594,7 @@ static void top_print_cpu_usage(struct perf_kwork *kwork)
u64 idle_time = stat->cpus_runtime[MAX_NR_CPUS].idle;
u64 hardirq_time = stat->cpus_runtime[MAX_NR_CPUS].irq;
u64 softirq_time = stat->cpus_runtime[MAX_NR_CPUS].softirq;
- int cpus_nr = bitmap_weight(stat->all_cpus_bitmap, MAX_NR_CPUS);
+ int cpus_nr = (int)bitmap_weight(stat->all_cpus_bitmap, MAX_NR_CPUS);
u64 cpus_total_time = stat->cpus_runtime[MAX_NR_CPUS].total;

printf("Total : %*.*f ms, %d cpus\n",
@@ -1801,7 +1800,7 @@ static int perf_kwork__read_events(struct perf_kwork *kwork)
session = perf_session__new(&data, &kwork->tool);
if (IS_ERR(session)) {
pr_debug("Error creating perf session\n");
- return PTR_ERR(session);
+ return (int)PTR_ERR(session);
}

symbol__init(&session->header.env);
@@ -2088,8 +2087,8 @@ static void top_calc_cpu_usage(struct perf_kwork *kwork)

top_subtract_irq_runtime(kwork, work);

- work->cpu_usage = work->total_runtime * 10000 /
- stat->cpus_runtime[work->cpu].total;
+ work->cpu_usage = (u32)(work->total_runtime *
+ 10000 / stat->cpus_runtime[work->cpu].total);

top_calc_idle_time(kwork, work);
next:
diff --git a/tools/perf/util/bpf_kwork_top.c b/tools/perf/util/bpf_kwork_top.c
index b6f187dd9136..808d0c84d26d 100644
--- a/tools/perf/util/bpf_kwork_top.c
+++ b/tools/perf/util/bpf_kwork_top.c
@@ -219,7 +219,7 @@ static void read_task_info(struct kwork_work *work)
int fd;
struct task_data data;
struct task_key key = {
- .pid = work->id,
+ .pid = (__u32)work->id,
.cpu = work->cpu,
};

--
2.49.0.504.g3bcea36a83-goog