Subject: linux-next: manual merge of the perf tree with the origin tree

From: [email-masked]
Date: Mon, 17 Jun 2024 17:19:14 +0100

Hi all,

Today's linux-next merge of the perf tree got a conflict in:

  tools/perf/builtin-record.c

between commit:

  5b3cde198878b ("Revert "perf record: Reduce memory for recording PERF_RECORD_LOST_SAMPLES event"")

from the origin tree and commit:

  6c1785cd75ef5 ("perf record: Ensure space for lost samples")

from the perf tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 0a8ba1323d64b..019305b94e5fc 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1926,7 +1926,7 @@ static void __record__save_lost_samples(struct record *rec, struct evsel *evsel,
 static void record__read_lost_samples(struct record *rec)
 {
 	struct perf_session *session = rec->session;
-	struct perf_record_lost_samples *lost = NULL;
+	struct perf_record_lost_samples_and_ids lost;
 	struct evsel *evsel;
 
 	/* there was an error during record__open */
@@ -1951,19 +1951,13 @@ static void record__read_lost_samples(struct record *rec)
 
 				if (perf_evsel__read(&evsel->core, x, y, &count) < 0) {
 					pr_debug("read LOST count failed\n");
-					goto out;
+					return;
 				}
 
 				if (count.lost) {
-					if (!lost) {
-						lost = zalloc(PERF_SAMPLE_MAX_SIZE);
-						if (!lost) {
-							pr_debug("Memory allocation failed\n");
-							return;
-						}
-						lost->header.type = PERF_RECORD_LOST_SAMPLES;
-					}
-					__record__save_lost_samples(rec, evsel, lost,
+					memset(&lost.lost, 0, sizeof(lost));
+					lost.lost.header.type = PERF_RECORD_LOST_SAMPLES;
+					__record__save_lost_samples(rec, evsel, &lost.lost,
 								    x, y, count.lost, 0);
 				}
 			}
@@ -1971,20 +1965,12 @@ static void record__read_lost_samples(struct record *rec)
 
 		lost_count = perf_bpf_filter__lost_count(evsel);
 		if (lost_count) {
-			if (!lost) {
-				lost = zalloc(PERF_SAMPLE_MAX_SIZE);
-				if (!lost) {
-					pr_debug("Memory allocation failed\n");
-					return;
-				}
-				lost->header.type = PERF_RECORD_LOST_SAMPLES;
-			}
-			__record__save_lost_samples(rec, evsel, lost, 0, 0, lost_count,
+			memset(&lost.lost, 0, sizeof(lost));
+			lost.lost.header.type = PERF_RECORD_LOST_SAMPLES;
+			__record__save_lost_samples(rec, evsel, &lost.lost, 0, 0, lost_count,
 						    PERF_RECORD_MISC_LOST_SAMPLES_BPF);
 		}
 	}
-out:
-	free(lost);
 }
 
 static volatile sig_atomic_t workload_exec_errno;
@@ -3196,7 +3182,7 @@ static int switch_output_setup(struct record *rec)
 	unsigned long val;
 
 	/*
-	 * If we're using --switch-output-events, then we imply its 
+	 * If we're using --switch-output-events, then we imply its
 	 * --switch-output=signal, as we'll send a SIGUSR2 from the side band
 	 *  thread to its parent.
 	 */