6.14-stable review patch. If anyone has any objections, please let me know.
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From: Ian Rogers irogers@google.com
[ Upstream commit 36e7748d33bf6a82e558009e03448e9321465e05 ]
With LTO builds, although regular builds could also see this as all the code is in one file, the datasym workload can realize the buf1.reserved data is never accessed. The compiler moves the variable to bss and only keeps the data1 and data2 parts as separate variables. This causes the symbol check to fail in the test. Make the variable volatile to disable the more aggressive optimization. Rename the variable to make which buf1 in perf is being referred to.
Before:
$ perf test -vv "data symbol" 126: Test data symbol: --- start --- test child forked, pid 299808 perf does not have symbol 'buf1' perf is missing symbols - skipping test ---- end(-2) ---- 126: Test data symbol : Skip $ nm perf|grep buf1 0000000000a5fa40 b buf1.0 0000000000a5fa48 b buf1.1
After:
$ nm perf|grep buf1 0000000000a53a00 d buf1 $ perf test -vv "data symbol"126: Test data symbol: --- start --- test child forked, pid 302166 a53a00-a53a39 l buf1 perf does have symbol 'buf1' Recording workload... Waiting for "perf record has started" message OK Cleaning up files... ---- end(0) ---- 126: Test data symbol : Ok
Fixes: 3dfc01fe9d12 ("perf test: Add 'datasym' test workload") Signed-off-by: Ian Rogers irogers@google.com Link: https://lore.kernel.org/r/20250226230109.314580-1-irogers@google.com Signed-off-by: Namhyung Kim namhyung@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/tests/shell/test_data_symbol.sh | 17 +++++++++-------- tools/perf/tests/workloads/datasym.c | 11 ++++++----- 2 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/tools/perf/tests/shell/test_data_symbol.sh b/tools/perf/tests/shell/test_data_symbol.sh index c86da02350596..7da606db97cb4 100755 --- a/tools/perf/tests/shell/test_data_symbol.sh +++ b/tools/perf/tests/shell/test_data_symbol.sh @@ -18,7 +18,7 @@ skip_if_no_mem_event() {
skip_if_no_mem_event || exit 2
-skip_test_missing_symbol buf1 +skip_test_missing_symbol workload_datasym_buf1
TEST_PROGRAM="perf test -w datasym" PERF_DATA=$(mktemp /tmp/__perf_test.perf.data.XXXXX) @@ -26,18 +26,19 @@ ERR_FILE=$(mktemp /tmp/__perf_test.stderr.XXXXX)
check_result() { # The memory report format is as below: - # 99.92% ... [.] buf1+0x38 + # 99.92% ... [.] workload_datasym_buf1+0x38 result=$(perf mem report -i ${PERF_DATA} -s symbol_daddr -q 2>&1 | - awk '/buf1/ { print $4 }') + awk '/workload_datasym_buf1/ { print $4 }')
- # Testing is failed if has no any sample for "buf1" + # Testing is failed if has no any sample for "workload_datasym_buf1" [ -z "$result" ] && return 1
while IFS= read -r line; do - # The "data1" and "data2" fields in structure "buf1" have - # offset "0x0" and "0x38", returns failure if detect any - # other offset value. - if [ "$line" != "buf1+0x0" ] && [ "$line" != "buf1+0x38" ]; then + # The "data1" and "data2" fields in structure + # "workload_datasym_buf1" have offset "0x0" and "0x38", returns + # failure if detect any other offset value. + if [ "$line" != "workload_datasym_buf1+0x0" ] && \ + [ "$line" != "workload_datasym_buf1+0x38" ]; then return 1 fi done <<< "$result" diff --git a/tools/perf/tests/workloads/datasym.c b/tools/perf/tests/workloads/datasym.c index 8ddb2aa6a049e..1d0b7d64e1ba1 100644 --- a/tools/perf/tests/workloads/datasym.c +++ b/tools/perf/tests/workloads/datasym.c @@ -10,7 +10,8 @@ typedef struct _buf { char data2; } buf __attribute__((aligned(64)));
-static buf buf1 = { +/* volatile to try to avoid the compiler seeing reserved as unused. */ +static volatile buf workload_datasym_buf1 = { /* to have this in the data section */ .reserved[0] = 1, }; @@ -34,8 +35,8 @@ static int datasym(int argc, const char **argv) alarm(sec);
while (!done) { - buf1.data1++; - if (buf1.data1 == 123) { + workload_datasym_buf1.data1++; + if (workload_datasym_buf1.data1 == 123) { /* * Add some 'noise' in the loop to work around errata * 1694299 on Arm N1. @@ -49,9 +50,9 @@ static int datasym(int argc, const char **argv) * longer a continuous repeating pattern that interacts * badly with the bias. */ - buf1.data1++; + workload_datasym_buf1.data1++; } - buf1.data2 += buf1.data1; + workload_datasym_buf1.data2 += workload_datasym_buf1.data1; } return 0; }