From: Eric Wong <e@80x24.org>
To: mwrap-perl@80x24.org
Subject: [PATCH 1/7] core: shrink src_loc 8 bytes on x86-64
Date: Mon, 19 Dec 2022 11:19:16 +0000 [thread overview]
Message-ID: <20221219111922.1079128-2-e@80x24.org> (raw)
In-Reply-To: <20221219111922.1079128-1-e@80x24.org>
We can rely on the stable value of ->loc_hash to assign the
mutex at when it requires locking rather than relying on a
monotonically increasing counter.
---
mwrap_core.h | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/mwrap_core.h b/mwrap_core.h
index 7681ca5..7be0a7a 100644
--- a/mwrap_core.h
+++ b/mwrap_core.h
@@ -93,7 +93,6 @@ union padded_mutex {
#else /* only tested on Linux + glibc */
# define STATIC_MTX_INIT_OK (1)
#endif
-static size_t mutex_i;
static union padded_mutex mutexes[MUTEX_NR] = {
#if STATIC_MTX_INIT_OK
[0 ... (MUTEX_NR-1)].mtx = PTHREAD_MUTEX_INITIALIZER
@@ -105,11 +104,6 @@ static union padded_mutex mutexes[MUTEX_NR] = {
static_assert(UINT32_MAX > PATH_MAX, "UINT32_MAX > PATH_MAX");
#endif
-static pthread_mutex_t *mutex_assign(void)
-{
- return &mutexes[uatomic_add_return(&mutex_i, 1) & MUTEX_MASK].mtx;
-}
-
static struct cds_lfht *lfht_new(size_t size)
{
return cds_lfht_new(size, 1, 0, CDS_LFHT_AUTO_RESIZE, 0);
@@ -163,7 +157,6 @@ struct src_file {
/* allocated via real_malloc, immortal for safety reasons */
struct src_loc {
- pthread_mutex_t *mtx;
size_t total;
size_t freed_bytes;
size_t allocations;
@@ -309,7 +302,6 @@ again:
if (!l) return l;
memcpy(l, k, n);
l->freed_bytes = 0;
- l->mtx = mutex_assign();
l->age_total = 0;
l->max_lifespan = 0;
l->freed_bytes = 0;
@@ -470,6 +462,13 @@ static void free_hdr_rcu(struct rcu_head *dead)
real_free(h->real);
}
+static pthread_mutex_t *src_loc_mutex_lock(const struct src_loc *l)
+{
+ pthread_mutex_t *mtx = &mutexes[l->loc_hash & MUTEX_MASK].mtx;
+ CHECK(int, 0, pthread_mutex_lock(mtx));
+ return mtx;
+}
+
void free(void *p)
{
if (p) {
@@ -485,11 +484,11 @@ void free(void *p)
uatomic_inc(&l->frees);
uatomic_add(&l->age_total, age);
- CHECK(int, 0, pthread_mutex_lock(l->mtx));
+ pthread_mutex_t *mtx = src_loc_mutex_lock(l);
cds_list_del_rcu(&h->anode);
if (age > l->max_lifespan)
l->max_lifespan = age;
- CHECK(int, 0, pthread_mutex_unlock(l->mtx));
+ CHECK(int, 0, pthread_mutex_unlock(mtx));
call_rcu(&h->as.dead, free_hdr_rcu);
} else {
@@ -509,9 +508,9 @@ alloc_insert_rcu(struct src_loc *l, struct alloc_hdr *h, size_t size,
h->as.live.loc = l;
h->as.live.gen = generation;
if (l) {
- CHECK(int, 0, pthread_mutex_lock(l->mtx));
+ pthread_mutex_t *mtx = src_loc_mutex_lock(l);
cds_list_add_rcu(&h->anode, &l->allocs);
- CHECK(int, 0, pthread_mutex_unlock(l->mtx));
+ CHECK(int, 0, pthread_mutex_unlock(mtx));
}
}
next prev parent reply other threads:[~2022-12-19 11:19 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-19 11:19 [PATCH 0/7] shrinkage Eric Wong
2022-12-19 11:19 ` Eric Wong [this message]
2022-12-19 11:19 ` [PATCH 2/7] core: shrink src_loc by another 8 bytes on x86-64 Eric Wong
2022-12-19 11:19 ` [PATCH 3/7] core: drop FreeBSD-specific mutex initialization Eric Wong
2022-12-19 11:19 ` [PATCH 4/7] calloc: consolidate ENOMEM handling Eric Wong
2022-12-19 11:19 ` [PATCH 5/7] *alloc: limit scope of RCU lock Eric Wong
2022-12-19 11:19 ` [PATCH 6/7] core: simplify callers of alloc_insert_rcu Eric Wong
2022-12-19 11:19 ` [PATCH 7/7] README: add some caveats (signalfd usage w/ current URCU) Eric Wong
2022-12-19 22:57 ` [WIP] attempt to workaround older URCU for signalfd Eric Wong
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