[PATCH 6.1.y 0/2] Backport dependency commits for 616b14b47a86 ("perf build: Conditionally define NDEBUG")

[PATCH 6.1.y 0/2] Backport dependency commits for 616b14b47a86 ("perf build: Conditionally define NDEBUG")

[Simon Liebold]

Hi, please backport the following two patches to 6.1.y:

- d1babea9c382 ("perf bench: Avoid NDEBUG warning")
- 984a785f25e5 ("perf block-range: Move debug code behind ifndef NDEBUG")

They are stable dependencies for commit 616b14b47a86 ("perf build: Conditionally
define NDEBUG") which was backported to v6.1.176 as 7bf35a0237d04.

That commit adds -DNDEBUG=1 to perf CFLAGS, which compiles out assert() calls,
leaving variables consumed only by asserts as unused-but-set. Combined with
-Werror this breaks the build:

    bench/find-bit-bench.c:64:22: error: variable 'old' set but not used
    util/block-range.c:20:13: error: variable 'old' set but not used

We need these two dependency patches, because both guard assert-only variables
with #ifndef NDEBUG so they are compiled out alongside the asserts they
validate.

Tested using our regression test suite including kselftest and LTP on various
EC2 instances.

Thanks.

- Simon

Ian Rogers (2):
  perf bench: Avoid NDEBUG warning
  perf block-range: Move debug code behind ifndef NDEBUG

 tools/perf/bench/find-bit-bench.c | 8 ++++++--
 tools/perf/util/block-range.c     | 6 +-----
 2 files changed, 7 insertions(+), 7 deletions(-)


base-commit: fdb6fcb41cc741ad5eaa7995f278dfcb94fdf795
-- 
2.50.1




Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christof Hellmis, Andreas Stieger
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597

[PATCH 6.1.y 1/2] perf bench: Avoid NDEBUG warning

[Simon Liebold]

From: Ian Rogers <irogers@google.com>

[ Upstream commit d1babea9c38282b58a6f822ab95027cba3165a42 ]

With NDEBUG set the asserts are compiled out. This yields
"unused-but-set-variable" variables. Move these variables behind
NDEBUG to avoid the warning.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230330183827.1412303-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Stable-dep-of: 616b14b47a86 ("perf build: Conditionally define NDEBUG")
Signed-off-by: Simon Liebold <simonlie@amazon.de>
---
 tools/perf/bench/find-bit-bench.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/bench/find-bit-bench.c b/tools/perf/bench/find-bit-bench.c
index 22b5cfe970237..80f051f9c20fd 100644
--- a/tools/perf/bench/find-bit-bench.c
+++ b/tools/perf/bench/find-bit-bench.c
@@ -61,7 +61,6 @@ static int do_for_each_set_bit(unsigned int num_bits)
 	double time_average, time_stddev;
 	unsigned int bit, i, j;
 	unsigned int set_bits, skip;
-	unsigned int old;
 
 	init_stats(&fb_time_stats);
 	init_stats(&tb_time_stats);
@@ -73,7 +72,10 @@ static int do_for_each_set_bit(unsigned int num_bits)
 			set_bit(i, to_test);
 
 		for (i = 0; i < outer_iterations; i++) {
-			old = accumulator;
+#ifndef NDEBUG
+			unsigned int old = accumulator;
+#endif
+
 			gettimeofday(&start, NULL);
 			for (j = 0; j < inner_iterations; j++) {
 				for_each_set_bit(bit, to_test, num_bits)
@@ -85,7 +87,9 @@ static int do_for_each_set_bit(unsigned int num_bits)
 			runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
 			update_stats(&fb_time_stats, runtime_us);
 
+#ifndef NDEBUG
 			old = accumulator;
+#endif
 			gettimeofday(&start, NULL);
 			for (j = 0; j < inner_iterations; j++) {
 				for (bit = 0; bit < num_bits; bit++) {
-- 
2.50.1




Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christof Hellmis, Andreas Stieger
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597

[PATCH 6.1.y 2/2] perf block-range: Move debug code behind ifndef NDEBUG

[Simon Liebold]

From: Ian Rogers <irogers@google.com>

[ Upstream commit 984a785f25e5b5db5fa673130b60dca6ca794406 ]

Make good on a comment and avoid a unused-but-set-variable warning.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230330183827.1412303-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Stable-dep-of: 616b14b47a86 ("perf build: Conditionally define NDEBUG")
Signed-off-by: Simon Liebold <simonlie@amazon.de>
---
 tools/perf/util/block-range.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/tools/perf/util/block-range.c b/tools/perf/util/block-range.c
index 1be4326575013..680e92774d0cd 100644
--- a/tools/perf/util/block-range.c
+++ b/tools/perf/util/block-range.c
@@ -11,11 +11,7 @@ struct {
 
 static void block_range__debug(void)
 {
-	/*
-	 * XXX still paranoid for now; see if we can make this depend on
-	 * DEBUG=1 builds.
-	 */
-#if 1
+#ifndef NDEBUG
 	struct rb_node *rb;
 	u64 old = 0; /* NULL isn't executable */
 
-- 
2.50.1




Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christof Hellmis, Andreas Stieger
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597

Re: [PATCH 6.1.y 0/2] Backport dependency commits for 616b14b47a86 ("perf build: Conditionally define NDEBUG")

[Sasha Levin]

> [PATCH 6.1.y 0/2] Backport dependency commits for 616b14b47a86
> ("perf build: Conditionally define NDEBUG")

Both patches queued for 6.1, thanks.

-- 
Thanks,
Sasha