linux-kernel - [PATCH 2/3] perf ftrace: Remove an unnecessary condition check in BPF

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Message-ID: <20250227191223.1288473-2-namhyung@kernel.org>
Date: Thu, 27 Feb 2025 11:12:22 -0800
From: Namhyung Kim <namhyung@...nel.org>
To: Arnaldo Carvalho de Melo <acme@...nel.org>,
	Ian Rogers <irogers@...gle.com>,
	Kan Liang <kan.liang@...ux.intel.com>
Cc: Jiri Olsa <jolsa@...nel.org>,
	Adrian Hunter <adrian.hunter@...el.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	linux-perf-users@...r.kernel.org,
	bpf@...r.kernel.org,
	Gabriele Monaco <gmonaco@...hat.com>
Subject: [PATCH 2/3] perf ftrace: Remove an unnecessary condition check in BPF

The bucket_num is set based on the {max,min}_latency already in
cmd_ftrace(), so no need to check it again in BPF.  Also I found
that it didn't pass the max_latency to BPF. :)

No functional changes intended.

Cc: Gabriele Monaco <gmonaco@...hat.com>
Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
 tools/perf/util/bpf_skel/func_latency.bpf.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/perf/util/bpf_skel/func_latency.bpf.c b/tools/perf/util/bpf_skel/func_latency.bpf.c
index 3d3d9f427c20876e..ad70547446786c54 100644
--- a/tools/perf/util/bpf_skel/func_latency.bpf.c
+++ b/tools/perf/util/bpf_skel/func_latency.bpf.c
@@ -125,8 +125,7 @@ int BPF_PROG(func_end)
 			// than the min latency desired.
 			if (val > 0) { // 1st entry: [ 1 unit .. bucket_range units )
 				key = val / bucket_range + 1;
-				if (key >= bucket_num ||
-					val >= max_latency - min_latency)
+				if (key >= bucket_num)
 					key = bucket_num - 1;
 			}
 
-- 
2.48.1.711.g2feabab25a-goog