From: Willy Tarreau <w@1wt.eu>
Date: Sat, 20 Feb 2021 10:38:56 +0000 (+0100)
Subject: MINOR: dynbuf: make the buffer wait queue per thread
X-Git-Tag: v2.4-dev9~4
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e8e5091510f667feeb36f68b8d2f4d9e8cf00dc0;p=thirdparty%2Fhaproxy.git

MINOR: dynbuf: make the buffer wait queue per thread

The buffer wait queue used to be global historically but this doest not
make any sense anymore given that the most common use case is to have
thread-local pools. Thus there's no point waking up waiters of other
threads after releasing an entry, as they won't benefit from it.

Let's move the queue head to the thread_info structure and use
ti->buffer_wq from now on.
---

diff --git a/include/haproxy/channel.h b/include/haproxy/channel.h
index de51d04678..812808c0e7 100644
--- a/include/haproxy/channel.h
+++ b/include/haproxy/channel.h
@@ -852,7 +852,7 @@ static inline int channel_alloc_buffer(struct channel *chn, struct buffer_wait *
 		return 1;
 
 	if (!MT_LIST_ADDED(&wait->list))
-		MT_LIST_ADDQ(&buffer_wq, &wait->list);
+		MT_LIST_ADDQ(&ti->buffer_wq, &wait->list);
 
 	return 0;
 }
diff --git a/include/haproxy/dynbuf.h b/include/haproxy/dynbuf.h
index 2a7aa47681..c26ad21f63 100644
--- a/include/haproxy/dynbuf.h
+++ b/include/haproxy/dynbuf.h
@@ -35,7 +35,6 @@
 #include <haproxy/pool.h>
 
 extern struct pool_head *pool_head_buffer;
-extern struct mt_list buffer_wq;
 
 int init_buffer();
 void buffer_dump(FILE *o, struct buffer *b, int from, int to);
@@ -192,13 +191,13 @@ static inline struct buffer *b_alloc_margin(struct buffer *buf, int margin)
  * passing a buffer to oneself in case of failed allocations (e.g. need two
  * buffers, get one, fail, release it and wake up self again). In case of
  * normal buffer release where it is expected that the caller is not waiting
- * for a buffer, NULL is fine.
+ * for a buffer, NULL is fine. It will wake waiters on the current thread only.
  */
 void __offer_buffer(void *from, unsigned int threshold);
 
 static inline void offer_buffers(void *from, unsigned int threshold)
 {
-	if (!MT_LIST_ISEMPTY(&buffer_wq))
+	if (!MT_LIST_ISEMPTY(&ti->buffer_wq))
 		__offer_buffer(from, threshold);
 }
 
diff --git a/include/haproxy/tinfo-t.h b/include/haproxy/tinfo-t.h
index f3badbd88e..6dc0458519 100644
--- a/include/haproxy/tinfo-t.h
+++ b/include/haproxy/tinfo-t.h
@@ -45,6 +45,8 @@ struct thread_info {
 #ifdef CONFIG_HAP_LOCAL_POOLS
 	struct list pool_lru_head;                         /* oldest objects   */
 #endif
+	struct mt_list buffer_wq;  /* buffer waiters */
+
 	/* pad to cache line (64B) */
 	char __pad[0];            /* unused except to check remaining room */
 	char __end[0] __attribute__((aligned(64)));
diff --git a/src/check.c b/src/check.c
index a09c67a7de..ff4effa179 100644
--- a/src/check.c
+++ b/src/check.c
@@ -1019,7 +1019,7 @@ struct buffer *check_get_buf(struct check *check, struct buffer *bptr)
 	    unlikely((buf = b_alloc_margin(bptr, 0)) == NULL)) {
 		check->buf_wait.target = check;
 		check->buf_wait.wakeup_cb = check_buf_available;
-		MT_LIST_ADDQ(&buffer_wq, &check->buf_wait.list);
+		MT_LIST_ADDQ(&ti->buffer_wq, &check->buf_wait.list);
 	}
 	return buf;
 }
diff --git a/src/dynbuf.c b/src/dynbuf.c
index ad2cde9265..395fa8a978 100644
--- a/src/dynbuf.c
+++ b/src/dynbuf.c
@@ -22,18 +22,20 @@
 
 struct pool_head *pool_head_buffer;
 
-/* list of objects waiting for at least one buffer */
-struct mt_list buffer_wq = LIST_HEAD_INIT(buffer_wq);
-
 /* perform minimal intializations, report 0 in case of error, 1 if OK. */
 int init_buffer()
 {
 	void *buffer;
+	int thr;
 
 	pool_head_buffer = create_pool("buffer", global.tune.bufsize, MEM_F_SHARED|MEM_F_EXACT);
 	if (!pool_head_buffer)
 		return 0;
 
+	for (thr = 0; thr < MAX_THREADS; thr++)
+		MT_LIST_INIT(&ha_thread_info[thr].buffer_wq);
+
+
 	/* The reserved buffer is what we leave behind us. Thus we always need
 	 * at least one extra buffer in minavail otherwise we'll end up waking
 	 * up tasks with no memory available, causing a lot of useless wakeups.
@@ -112,7 +114,7 @@ void __offer_buffer(void *from, unsigned int threshold)
 	 */
 	avail = pool_head_buffer->allocated - pool_head_buffer->used - global.tune.reserved_bufs / 2;
 
-	mt_list_for_each_entry_safe(wait, &buffer_wq, list, elt1, elt2) {
+	mt_list_for_each_entry_safe(wait, &ti->buffer_wq, list, elt1, elt2) {
 		if (avail <= threshold)
 			break;
 
diff --git a/src/flt_spoe.c b/src/flt_spoe.c
index b9471d9170..27a15b6c16 100644
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -2828,7 +2828,7 @@ spoe_acquire_buffer(struct buffer *buf, struct buffer_wait *buffer_wait)
 	if (b_alloc_margin(buf, global.tune.reserved_bufs))
 		return 1;
 
-	MT_LIST_ADDQ(&buffer_wq, &buffer_wait->list);
+	MT_LIST_ADDQ(&ti->buffer_wq, &buffer_wait->list);
 	return 0;
 }
 
diff --git a/src/mux_fcgi.c b/src/mux_fcgi.c
index a2c1c86c6a..2ff7aa9098 100644
--- a/src/mux_fcgi.c
+++ b/src/mux_fcgi.c
@@ -608,7 +608,7 @@ static inline struct buffer *fcgi_get_buf(struct fcgi_conn *fconn, struct buffer
 	    unlikely((buf = b_alloc_margin(bptr, 0)) == NULL)) {
 		fconn->buf_wait.target = fconn;
 		fconn->buf_wait.wakeup_cb = fcgi_buf_available;
-		MT_LIST_ADDQ(&buffer_wq, &fconn->buf_wait.list);
+		MT_LIST_ADDQ(&ti->buffer_wq, &fconn->buf_wait.list);
 	}
 	return buf;
 }
diff --git a/src/mux_h1.c b/src/mux_h1.c
index 63339351f2..077f4ea2dc 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -452,7 +452,7 @@ static inline struct buffer *h1_get_buf(struct h1c *h1c, struct buffer *bptr)
 	    unlikely((buf = b_alloc_margin(bptr, 0)) == NULL)) {
 		h1c->buf_wait.target = h1c;
 		h1c->buf_wait.wakeup_cb = h1_buf_available;
-		MT_LIST_ADDQ(&buffer_wq, &h1c->buf_wait.list);
+		MT_LIST_ADDQ(&ti->buffer_wq, &h1c->buf_wait.list);
 	}
 	return buf;
 }
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 21c14b8737..cfa5f8c4d4 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -810,7 +810,7 @@ static inline struct buffer *h2_get_buf(struct h2c *h2c, struct buffer *bptr)
 	    unlikely((buf = b_alloc_margin(bptr, 0)) == NULL)) {
 		h2c->buf_wait.target = h2c;
 		h2c->buf_wait.wakeup_cb = h2_buf_available;
-		MT_LIST_ADDQ(&buffer_wq, &h2c->buf_wait.list);
+		MT_LIST_ADDQ(&ti->buffer_wq, &h2c->buf_wait.list);
 	}
 	return buf;
 }
diff --git a/src/stream.c b/src/stream.c
index 9394ac0a74..d747211623 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -773,7 +773,7 @@ static int stream_alloc_work_buffer(struct stream *s)
 	if (b_alloc_margin(&s->res.buf, 0))
 		return 1;
 
-	MT_LIST_ADDQ(&buffer_wq, &s->buffer_wait.list);
+	MT_LIST_ADDQ(&ti->buffer_wq, &s->buffer_wait.list);
 	return 0;
 }