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authorNamhyung Kim <namhyung@kernel.org>2025-04-09 18:02:52 -0700
committerNamhyung Kim <namhyung@kernel.org>2025-04-11 09:22:49 -0700
commit2b70702917337a8d6d07f03eed961e0119091647 (patch)
tree583a8f1a42cdc166e141770f50b6bb7e7ec0a8c6 /tools
parent1293dacbbd43ab9848ac4655f6f2ba1dcc5a96ad (diff)
perf tools: Remove evsel__handle_error_quirks()
The evsel__handle_error_quirks() is to fixup invalid event attributes on some architecture based on the error code. Currently it's only used for AMD to disable precise_ip not to use IBS which has more restrictions. But the commit c33aea446bf555ab changed call evsel__precise_ip_fallback for any errors so there's no difference with the above function. To make matter worse, it caused a problem with branch stack on Zen3. The IBS doesn't support branch stack so it should use a regular core PMU event. The default event is set precise_max and it starts with 3. And evsel__precise_ip_fallback() tries with it and reduces the level one by one. At last it tries with 0 but it also failed on Zen3 since the branch stack is not supported for the cycles event. At this point, evsel__precise_ip_fallback() restores the original precise_ip value (3) in the hope that it can succeed with other modifier (like exclude_kernel). Then evsel__handle_error_quirks() see it has precise_ip != 0 and make it retry with 0. This created an infinite loop. Before: $ perf record -b -vv |& grep removing removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD ... After: $ perf record -b true Error: Failure to open event 'cycles:P' on PMU 'cpu' which will be removed. Invalid event (cycles:P) in per-thread mode, enable system wide with '-a'. Error: Failure to open any events for recording. Fixes: c33aea446bf555ab ("perf tools: Fix precise_ip fallback logic") Tested-by: Chun-Tse Shao <ctshao@google.com> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20250410010252.402221-1-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/evsel.c22
1 files changed, 0 insertions, 22 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 1974395492d7..3c030da2e477 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2566,25 +2566,6 @@ check:
return false;
}
-static bool evsel__handle_error_quirks(struct evsel *evsel, int error)
-{
- /*
- * AMD core PMU tries to forward events with precise_ip to IBS PMU
- * implicitly. But IBS PMU has more restrictions so it can fail with
- * supported event attributes. Let's forward it back to the core PMU
- * by clearing precise_ip only if it's from precise_max (:P).
- */
- if ((error == -EINVAL || error == -ENOENT) && x86__is_amd_cpu() &&
- evsel->core.attr.precise_ip && evsel->precise_max) {
- evsel->core.attr.precise_ip = 0;
- pr_debug2_peo("removing precise_ip on AMD\n");
- display_attr(&evsel->core.attr);
- return true;
- }
-
- return false;
-}
-
static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
struct perf_thread_map *threads,
int start_cpu_map_idx, int end_cpu_map_idx)
@@ -2730,9 +2711,6 @@ try_fallback:
if (evsel__precise_ip_fallback(evsel))
goto retry_open;
- if (evsel__handle_error_quirks(evsel, err))
- goto retry_open;
-
out_close:
if (err)
threads->err_thread = thread;