tmp_attrs in apply_wqattrs_prepare() is just temporary attrs, we can use
wq_update_unbound_numa_attrs_buf for it like wq_update_unbound_numa();
The wq_update_unbound_numa_attrs_buf is renamed to wq_calc_node_attrs_buf
since it is used both for apply_wqattrs_prepare() and wq_update_unbound_numa().
The comment for using wq_calc_node_attrs_buf in wq_update_unbound_numa()
is also moved to the defination of the wq_calc_node_attrs_buf.
This change also avoids frequently alloc/free the tmp_attrs for every
workqueue when the low level cpumask is being updated.
Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com>
---
kernel/workqueue.c | 31 +++++++++++++------------------
1 file changed, 13 insertions(+), 18 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0c2f819..4a40165 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -295,8 +295,13 @@ module_param_named(power_efficient, wq_power_efficient,
bool, 0444);
static bool wq_numa_enabled; /* unbound NUMA affinity enabled */
-/* buf for wq_update_unbound_numa_attrs(), protected by CPU hotplug exclusion
*/
-static struct workqueue_attrs *wq_update_unbound_numa_attrs_buf;
+/*
+ * PL: resulted attrs of wq_calc_node_cpumask() for apply_wqattrs_prepare()
+ * and wq_update_unbound_numa().
+ * We don't wanna alloc/free temporary attrs for each call. Let's preallocate
+ * one with the access protection of wq_pool_mutex.
+ */
+static struct workqueue_attrs *wq_calc_node_attrs_buf;
static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */
static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */
@@ -3515,7 +3520,7 @@ apply_wqattrs_prepare(struct workqueue_struct *wq,
const struct workqueue_attrs *attrs)
{
struct apply_wqattrs_ctx *ctx;
- struct workqueue_attrs *new_attrs, *tmp_attrs;
+ struct workqueue_attrs *new_attrs, *tmp_attrs = wq_calc_node_attrs_buf;
struct pool_workqueue *pwq;
int node;
@@ -3525,8 +3530,7 @@ apply_wqattrs_prepare(struct workqueue_struct *wq,
GFP_KERNEL);
new_attrs = alloc_workqueue_attrs(GFP_KERNEL);
- tmp_attrs = alloc_workqueue_attrs(GFP_KERNEL);
- if (!ctx || !new_attrs || !tmp_attrs)
+ if (!ctx || !new_attrs)
goto out_free;
/*
@@ -3585,11 +3589,9 @@ apply_wqattrs_prepare(struct workqueue_struct *wq,
ctx->attrs = new_attrs;
ctx->wq = wq;
- free_workqueue_attrs(tmp_attrs);
return ctx;
out_free:
- free_workqueue_attrs(tmp_attrs);
free_workqueue_attrs(new_attrs);
apply_wqattrs_cleanup(ctx);
return NULL;
@@ -3713,7 +3715,7 @@ static void wq_update_unbound_numa(struct
workqueue_struct *wq, int cpu,
int node = cpu_to_node(cpu);
int cpu_off = online ? -1 : cpu;
struct pool_workqueue *old_pwq = NULL, *pwq;
- struct workqueue_attrs *target_attrs;
+ struct workqueue_attrs *target_attrs = wq_calc_node_attrs_buf;
cpumask_t *cpumask;
lockdep_assert_held(&wq_pool_mutex);
@@ -3722,14 +3724,6 @@ static void wq_update_unbound_numa(struct
workqueue_struct *wq, int cpu,
wq->unbound_attrs->no_numa)
return;
- /*
- * We don't wanna alloc/free wq_attrs for each wq for each CPU.
- * Let's use a preallocated one. The following buf is protected by
- * CPU hotplug exclusion.
- */
- target_attrs = wq_update_unbound_numa_attrs_buf;
- cpumask = target_attrs->cpumask;
-
copy_workqueue_attrs(target_attrs, wq->unbound_attrs);
/*
@@ -3738,6 +3732,7 @@ static void wq_update_unbound_numa(struct
workqueue_struct *wq, int cpu,
* and create a new one if they don't match. If the target cpumask
* equals the default pwq's, the default pwq should be used.
*/
+ cpumask = target_attrs->cpumask;
if (wq_calc_node_cpumask(wq->dfl_pwq->pool->attrs, node, cpu_off,
cpumask)) {
pwq = unbound_pwq_by_node(wq, node);
if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask))
@@ -5208,8 +5203,8 @@ static void __init wq_numa_init(void)
return;
}
- wq_update_unbound_numa_attrs_buf = alloc_workqueue_attrs(GFP_KERNEL);
- BUG_ON(!wq_update_unbound_numa_attrs_buf);
+ wq_calc_node_attrs_buf = alloc_workqueue_attrs(GFP_KERNEL);
+ BUG_ON(!wq_calc_node_attrs_buf);
/*
* We want masks of possible CPUs of each node which isn't readily
--
2.1.0
--
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