From eef4fee5e52071d563d9a851df1c09869215ee15 Mon Sep 17 00:00:00 2001
From: Ian Rogers <irogers@google.com>
Date: Fri, 26 May 2023 11:33:54 -0700
Subject: [PATCH] perf lock: Dynamically allocate lockhash_table

lockhash_table is 32,768 bytes in .bss, make it a memory allocation so
that the space is freed for non-lock perf commands.

Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20230526183401.2326121-10-irogers@google.com
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ross Zwisler <zwisler@chromium.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-lock.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 70b14ba5fdd520..fc8356bd6e3a1d 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -48,7 +48,7 @@ static struct target target;
 #define LOCKHASH_BITS		12
 #define LOCKHASH_SIZE		(1UL << LOCKHASH_BITS)
 
-static struct hlist_head lockhash_table[LOCKHASH_SIZE];
+static struct hlist_head *lockhash_table;
 
 #define __lockhashfn(key)	hash_long((unsigned long)key, LOCKHASH_BITS)
 #define lockhashentry(key)	(lockhash_table + __lockhashfn((key)))
@@ -1871,7 +1871,6 @@ static int __cmd_contention(int argc, const char **argv)
 	};
 	struct lock_contention con = {
 		.target = &target,
-		.result = &lockhash_table[0],
 		.map_nr_entries = bpf_map_entries,
 		.max_stack = max_stack_depth,
 		.stack_skip = stack_skip,
@@ -1880,10 +1879,17 @@ static int __cmd_contention(int argc, const char **argv)
 		.owner = show_lock_owner,
 	};
 
+	lockhash_table = calloc(LOCKHASH_SIZE, sizeof(*lockhash_table));
+	if (!lockhash_table)
+		return -ENOMEM;
+
+	con.result = &lockhash_table[0];
+
 	session = perf_session__new(use_bpf ? NULL : &data, &eops);
 	if (IS_ERR(session)) {
 		pr_err("Initializing perf session failed\n");
-		return PTR_ERR(session);
+		err = PTR_ERR(session);
+		goto out_delete;
 	}
 
 	con.machine = &session->machines.host;
@@ -1983,6 +1989,7 @@ static int __cmd_contention(int argc, const char **argv)
 	evlist__delete(con.evlist);
 	lock_contention_finish();
 	perf_session__delete(session);
+	zfree(&lockhash_table);
 	return err;
 }
 
@@ -2348,6 +2355,10 @@ int cmd_lock(int argc, const char **argv)
 	unsigned int i;
 	int rc = 0;
 
+	lockhash_table = calloc(LOCKHASH_SIZE, sizeof(*lockhash_table));
+	if (!lockhash_table)
+		return -ENOMEM;
+
 	for (i = 0; i < LOCKHASH_SIZE; i++)
 		INIT_HLIST_HEAD(lockhash_table + i);
 
@@ -2369,7 +2380,7 @@ int cmd_lock(int argc, const char **argv)
 		rc = __cmd_report(false);
 	} else if (!strcmp(argv[0], "script")) {
 		/* Aliased to 'perf script' */
-		return cmd_script(argc, argv);
+		rc = cmd_script(argc, argv);
 	} else if (!strcmp(argv[0], "info")) {
 		if (argc) {
 			argc = parse_options(argc, argv,
@@ -2403,5 +2414,6 @@ int cmd_lock(int argc, const char **argv)
 		usage_with_options(lock_usage, lock_options);
 	}
 
+	zfree(&lockhash_table);
 	return rc;
 }