From: Jens Axboe <jens.axboe@oracle.com>
Date: Mon, 6 Jul 2009 11:43:46 +0000 (+0200)
Subject: Improve async verify offload efficiency
X-Git-Tag: fio-1.31~8
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=e53ab27c7425241d64e8d64ad77850a776c01375;ds=sidebyside

Improve async verify offload efficiency

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/flist.h b/flist.h
index e62f4b29..95023c75 100644
--- a/flist.h
+++ b/flist.h
@@ -117,6 +117,36 @@ static inline int flist_empty(const struct flist_head *head)
 	return head->next == head;
 }
 
+static inline void __flist_splice(const struct flist_head *list,
+				  struct flist_head *prev,
+				  struct flist_head *next)
+{
+	struct flist_head *first = list->next;
+	struct flist_head *last = list->prev;
+
+	first->prev = prev;
+	prev->next = first;
+
+	last->next = next;
+	next->prev = last;
+}
+
+static inline void flist_splice(const struct flist_head *list,
+				struct flist_head *head)
+{
+	if (!flist_empty(list))
+		__flist_splice(list, head, head->next);
+}
+
+static inline void flist_splice_init(struct flist_head *list,
+				    struct flist_head *head)
+{
+	if (!flist_empty(list)) {
+		__flist_splice(list, head, head->next);
+		INIT_FLIST_HEAD(list);
+	}
+}
+
 /**
  * flist_entry - get the struct for this entry
  * @ptr:	the &struct flist_head pointer.
diff --git a/verify.c b/verify.c
index 5dd9ee33..978e77b8 100644
--- a/verify.c
+++ b/verify.c
@@ -756,6 +756,8 @@ static void *verify_async_thread(void *data)
 	}
 
 	do {
+		FLIST_HEAD(list);
+
 		read_barrier();
 		if (td->verify_thread_exit)
 			break;
@@ -771,17 +773,19 @@ static void *verify_async_thread(void *data)
 			}
 		}
 
-		if (flist_empty(&td->verify_list)) {
-			pthread_mutex_unlock(&td->io_u_lock);
+		flist_splice_init(&td->verify_list, &list);
+		pthread_mutex_unlock(&td->io_u_lock);
+
+		if (flist_empty(&list))
 			continue;
-		}
 
-		io_u = flist_entry(td->verify_list.next, struct io_u, list);
-		flist_del_init(&io_u->list);
-		pthread_mutex_unlock(&td->io_u_lock);
+		while (!flist_empty(&list)) {
+			io_u = flist_entry(list.next, struct io_u, list);
+			flist_del_init(&io_u->list);
 
-		ret = verify_io_u(td, io_u);
-		put_io_u(td, io_u);
+			ret |= verify_io_u(td, io_u);
+			put_io_u(td, io_u);
+		}
 	} while (!ret);
 
 done: