On 11/28/18 4:24 PM, Nikolay Borisov wrote:
On 28.11.18 г. 5:11 ч., Su Yue wrote:
To implement priority aware allocator, this patch:
Introduces struct btrfs_priority_tree which contains block groups
in same level.
Adds member priority to struct btrfs_block_group_cache and pointer
points to the priority tree it's located.
Adds member priority_trees to struct btrfs_space_info to represents
priority trees in different raid types.
Signed-off-by: Su Yue <suy.fnst@xxxxxxxxxxxxxx>
---
fs/btrfs/ctree.h | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e62824cae00a..5c4651d8a524 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -437,6 +437,8 @@ struct btrfs_space_info {
struct rw_semaphore groups_sem;
/* for block groups in our same type */
struct list_head block_groups[BTRFS_NR_RAID_TYPES];
+ /* for priority trees in our same type */
+ struct rb_root priority_trees[BTRFS_NR_RAID_TYPES];
wait_queue_head_t wait;
struct kobject kobj;
@@ -558,6 +560,21 @@ struct btrfs_full_stripe_locks_tree {
struct mutex lock;
};
+/*
+ * Tree to record all block_groups in same priority level.
+ * Only used in priority aware allocator.
+ */
+struct btrfs_priority_tree {
+ /* protected by groups_sem */
+ struct rb_root block_groups;
+ struct rw_semaphore groups_sem;
+
+ /* for different level priority trees in same index*/
+ struct rb_node node;
+
+ int level;
Do you ever expect the level to be a negative number? If not then use
u8/u32 depending on the range of levels you expect.
Indeed, level is not expected to be negative. u8 is more proper.
+};
+
struct btrfs_block_group_cache {
struct btrfs_key key;
struct btrfs_block_group_item item;
@@ -571,6 +588,8 @@ struct btrfs_block_group_cache {
u64 flags;
u64 cache_generation;
+ /* It's used only when priority aware allocator is enabled. */
+ long priority;
What's the range of priorities you are expecting, wouldn't an u8 be
sufficient, that gives us 256 priorities?
The 6th patch introduces three special priorities. That's what I called
dirty codes.
Thanks,
Su
/*
* If the free space extent count exceeds this number, convert the block
* group to bitmaps.
@@ -616,6 +635,9 @@ struct btrfs_block_group_cache {
/* for block groups in the same raid type */
struct list_head list;
+ /* for block groups in the same priority level */
+ struct rb_node node;
+
/* usage count */
atomic_t count;
@@ -670,6 +692,8 @@ struct btrfs_block_group_cache {
/* Record locked full stripes for RAID5/6 block group */
struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
+
+ struct btrfs_priority_tree *priority_tree;
};
/* delayed seq elem */
