[PATCH v1 09/16] perf lock: Dynamically allocate lockhash_table

From: Ian Rogers
Date: Thu May 25 2023 - 03:13:18 EST


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

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
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 70b14ba5fdd5..fc8356bd6e3a 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;
}
--
2.40.1.698.g37aff9b760-goog