[PATCH 1/6] perf lock: Convert lockhash_table to use hlist

From: Namhyung Kim
Date: Wed Jan 26 2022 - 19:01:01 EST


The hlist_head has a single entry so we can save some memory.

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/builtin-lock.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index d70131b7b1b1..43139166f02e 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -38,13 +38,13 @@ static struct perf_session *session;
#define LOCKHASH_BITS 12
#define LOCKHASH_SIZE (1UL << LOCKHASH_BITS)

-static struct list_head lockhash_table[LOCKHASH_SIZE];
+static struct hlist_head lockhash_table[LOCKHASH_SIZE];

#define __lockhashfn(key) hash_long((unsigned long)key, LOCKHASH_BITS)
#define lockhashentry(key) (lockhash_table + __lockhashfn((key)))

struct lock_stat {
- struct list_head hash_entry;
+ struct hlist_node hash_entry;
struct rb_node rb; /* used for sorting */

/*
@@ -317,10 +317,10 @@ static struct lock_stat *pop_from_result(void)

static struct lock_stat *lock_stat_findnew(void *addr, const char *name)
{
- struct list_head *entry = lockhashentry(addr);
+ struct hlist_head *entry = lockhashentry(addr);
struct lock_stat *ret, *new;

- list_for_each_entry(ret, entry, hash_entry) {
+ hlist_for_each_entry(ret, entry, hash_entry) {
if (ret->addr == addr)
return ret;
}
@@ -339,7 +339,7 @@ static struct lock_stat *lock_stat_findnew(void *addr, const char *name)
strcpy(new->name, name);
new->wait_time_min = ULLONG_MAX;

- list_add(&new->hash_entry, entry);
+ hlist_add_head(&new->hash_entry, entry);
return new;

alloc_failed:
@@ -781,7 +781,7 @@ static void dump_map(void)

pr_info("Address of instance: name of class\n");
for (i = 0; i < LOCKHASH_SIZE; i++) {
- list_for_each_entry(st, &lockhash_table[i], hash_entry) {
+ hlist_for_each_entry(st, &lockhash_table[i], hash_entry) {
pr_info(" %p: %s\n", st->addr, st->name);
}
}
@@ -838,7 +838,7 @@ static void sort_result(void)
struct lock_stat *st;

for (i = 0; i < LOCKHASH_SIZE; i++) {
- list_for_each_entry(st, &lockhash_table[i], hash_entry) {
+ hlist_for_each_entry(st, &lockhash_table[i], hash_entry) {
insert_to_result(st, compare);
}
}
@@ -990,7 +990,7 @@ int cmd_lock(int argc, const char **argv)
int rc = 0;

for (i = 0; i < LOCKHASH_SIZE; i++)
- INIT_LIST_HEAD(lockhash_table + i);
+ INIT_HLIST_HEAD(lockhash_table + i);

argc = parse_options_subcommand(argc, argv, lock_options, lock_subcommands,
lock_usage, PARSE_OPT_STOP_AT_NON_OPTION);
--
2.35.0.rc0.227.g00780c9af4-goog