From: Matthew Wilcox <willy@infradead.org>
Date: Mon, 18 Feb 2019 14:58:53 +0000 (-0500)
Subject: workqueue: Convert to XArray
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=130c39cb978060c8ea4aa95f11e00f090303360f;p=users%2Fwilly%2Fxarray.git

workqueue: Convert to XArray

Signed-off-by: Matthew Wilcox <willy@infradead.org>
---

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 601d61150b65..c3d612e63761 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -327,7 +327,7 @@ module_param_named(debug_force_rr_cpu, wq_debug_force_rr_cpu, bool, 0644);
 /* the per-cpu worker pools */
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS], cpu_worker_pools);
 
-static DEFINE_IDR(worker_pool_idr);	/* PR: idr of all pools */
+static DEFINE_XARRAY_ALLOC(worker_pools);	/* PR: array of all pools */
 
 /* PL: hash of all unbound pools keyed by pool->attrs */
 static DEFINE_HASHTABLE(unbound_pool_hash, UNBOUND_POOL_HASH_ORDER);
@@ -393,7 +393,7 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
  * ignored.
  */
 #define for_each_pool(pool, pi)						\
-	idr_for_each_entry(&worker_pool_idr, pool, pi)			\
+	xa_for_each(&worker_pools, pi, pool)				\
 		if (({ assert_rcu_or_pool_mutex(); false; })) { }	\
 		else
 
@@ -535,17 +535,10 @@ static inline void debug_work_deactivate(struct work_struct *work) { }
  */
 static int worker_pool_assign_id(struct worker_pool *pool)
 {
-	int ret;
-
 	lockdep_assert_held(&wq_pool_mutex);
 
-	ret = idr_alloc(&worker_pool_idr, pool, 0, WORK_OFFQ_POOL_NONE,
-			GFP_KERNEL);
-	if (ret >= 0) {
-		pool->id = ret;
-		return 0;
-	}
-	return ret;
+	return xa_alloc(&worker_pools, &pool->id, pool,
+			XA_LIMIT(0, WORK_OFFQ_POOL_NONE - 1), GFP_KERNEL);
 }
 
 /**
@@ -722,7 +715,7 @@ static struct worker_pool *get_work_pool(struct work_struct *work)
 	if (pool_id == WORK_OFFQ_POOL_NONE)
 		return NULL;
 
-	return idr_find(&worker_pool_idr, pool_id);
+	return xa_load(&worker_pools, pool_id);
 }
 
 /**
@@ -3526,8 +3519,7 @@ static void put_unbound_pool(struct worker_pool *pool)
 		return;
 
 	/* release id and unhash */
-	if (pool->id >= 0)
-		idr_remove(&worker_pool_idr, pool->id);
+	xa_erase(&worker_pools, pool->id);
 	hash_del(&pool->hash_node);
 
 	/*
@@ -4700,7 +4692,7 @@ void show_workqueue_state(void)
 	struct workqueue_struct *wq;
 	struct worker_pool *pool;
 	unsigned long flags;
-	int pi;
+	unsigned long pi;
 
 	rcu_read_lock();
 
@@ -4989,7 +4981,7 @@ int workqueue_online_cpu(unsigned int cpu)
 {
 	struct worker_pool *pool;
 	struct workqueue_struct *wq;
-	int pi;
+	unsigned long pi;
 
 	mutex_lock(&wq_pool_mutex);
 
@@ -5695,7 +5687,7 @@ static void wq_watchdog_timer_fn(struct timer_list *unused)
 	unsigned long thresh = READ_ONCE(wq_watchdog_thresh) * HZ;
 	bool lockup_detected = false;
 	struct worker_pool *pool;
-	int pi;
+	unsigned long pi;
 
 	if (!thresh)
 		return;
@@ -5849,7 +5841,7 @@ static void __init wq_numa_init(void)
  *
  * This is the first half of two-staged workqueue subsystem initialization
  * and invoked as soon as the bare basics - memory allocation, cpumasks and
- * idr are up.  It sets up all the data structures and system workqueues
+ * xarray are up.  It sets up all the data structures and system workqueues
  * and allows early boot code to create workqueues and queue/cancel work
  * items.  Actual work item execution starts only after kthreads can be
  * created and scheduled right before early initcalls.