[PATCH 05/13] block: reorganize struct blk_zone_wplug

Damien Le Moal
2025-10-31T06:17:04Z

Reorganize the fields of struct blk_zone_wplug to remove a hole after
the wp_offset field and avoid having the bio_work structure split
between 2 cache lines.

No functional changes.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
---
block/blk-zoned.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 603ed8dc472c..29891253a920 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -39,6 +39,11 @@ static const char *const zone_cond_name[] = {
/*
* Per-zone write plug.
* @node: hlist_node structure for managing the plug using a hash table.
+ * @bio_list: The list of BIOs that are currently plugged.
+ * @bio_work: Work struct to handle issuing of plugged BIOs
+ * @rcu_head: RCU head to free zone write plugs with an RCU grace period.
+ * @disk: The gendisk the plug belongs to.
+ * @lock: Spinlock to atomically manipulate the plug.
* @ref: Zone write plug reference counter. A zone write plug reference is
* always at least 1 when the plug is hashed in the disk plug hash table.
* The reference is incremented whenever a new BIO needing plugging is
@@ -48,27 +53,22 @@ static const char *const zone_cond_name[] = {
* reference is dropped whenever the zone of the zone write plug is reset,
* finished and when the zone becomes full (last write BIO to the zone
* completes).
- * @lock: Spinlock to atomically manipulate the plug.
* @flags: Flags indicating the plug state.
* @zone_no: The number of the zone the plug is managing.
* @wp_offset: The zone write pointer location relative to the start of the zone
* as a number of 512B sectors.
- * @bio_list: The list of BIOs that are currently plugged.
- * @bio_work: Work struct to handle issuing of plugged BIOs
- * @rcu_head: RCU head to free zone write plugs with an RCU grace period.
- * @disk: The gendisk the plug belongs to.
*/
struct blk_zone_wplug {
struct hlist_node node;
- refcount_t ref;
- spinlock_t lock;
- unsigned int flags;
- unsigned int zone_no;
- unsigned int wp_offset;
struct bio_list bio_list;
struct work_struct bio_work;
struct rcu_head rcu_head;
struct gendisk *disk;
+ spinlock_t lock;
+ refcount_t ref;
+ unsigned int flags;
+ unsigned int zone_no;
+ unsigned int wp_offset;
};

static inline unsigned int disk_zone_wplugs_hash_size(struct gendisk *disk)
--
2.51.0