f2fs: wake up discard_thread iff there is a candidate
This patch fixes to avoid needless wake ups.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index a04bd75..4e2529f 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1494,8 +1494,7 @@
kmem_cache_free(discard_entry_slab, entry);
}
- dcc->discard_wake = 1;
- wake_up_interruptible_all(&dcc->discard_wait_queue);
+ wake_up_discard_thread(sbi, false);
}
static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index b9b4f85..613b2fa 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -798,3 +798,28 @@
wbc->nr_to_write = desired;
return desired - nr_to_write;
}
+
+static inline void wake_up_discard_thread(struct f2fs_sb_info *sbi, bool force)
+{
+ struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+ bool wakeup = false;
+ int i;
+
+ if (force)
+ goto wake_up;
+
+ mutex_lock(&dcc->cmd_lock);
+ for (i = MAX_PLIST_NUM - 1;
+ i >= 0 && plist_issue(dcc->pend_list_tag[i]); i--) {
+ if (!list_empty(&dcc->pend_list[i])) {
+ wakeup = true;
+ break;
+ }
+ }
+ mutex_unlock(&dcc->cmd_lock);
+ if (!wakeup)
+ return;
+wake_up:
+ dcc->discard_wake = 1;
+ wake_up_interruptible_all(&dcc->discard_wait_queue);
+}
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index b9ad904..962735d 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -178,13 +178,9 @@
if (!strcmp(a->attr.name, "iostat_enable") && *ui == 0)
f2fs_reset_iostat(sbi);
if (!strcmp(a->attr.name, "gc_urgent") && t == 1 && sbi->gc_thread) {
- struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
-
sbi->gc_thread->gc_wake = 1;
wake_up_interruptible_all(&sbi->gc_thread->gc_wait_queue_head);
-
- dcc->discard_wake = 1;
- wake_up_interruptible_all(&dcc->discard_wait_queue);
+ wake_up_discard_thread(sbi, true);
}
return count;