diff mbox series

[14/19] mm: Create/affine kswapd to its preferred node

Message ID 20240916224925.20540-15-frederic@kernel.org (mailing list archive)
State New
Headers show
Series None | expand

Commit Message

Frederic Weisbecker Sept. 16, 2024, 10:49 p.m. UTC 
kswapd is dedicated to a specific node. As such it wants to be
preferrably affine to it, memory and CPUs-wise.

Use the proper kthread API to achieve that. As a bonus it takes care of
CPU-hotplug events and CPU-isolation on its behalf.

Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
 mm/vmscan.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

Comments

Michal Hocko Sept. 17, 2024, 6:05 a.m. UTC | #1 
On Tue 17-09-24 00:49:18, Frederic Weisbecker wrote:
> kswapd is dedicated to a specific node. As such it wants to be
> preferrably affine to it, memory and CPUs-wise.
> 
> Use the proper kthread API to achieve that. As a bonus it takes care of
> CPU-hotplug events and CPU-isolation on its behalf.
> 
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  mm/vmscan.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index bd489c1af228..00a7f1e92447 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -7139,10 +7139,6 @@ static int kswapd(void *p)
>  	unsigned int highest_zoneidx = MAX_NR_ZONES - 1;
>  	pg_data_t *pgdat = (pg_data_t *)p;
>  	struct task_struct *tsk = current;
> -	const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
> -
> -	if (!cpumask_empty(cpumask))
> -		set_cpus_allowed_ptr(tsk, cpumask);
>  
>  	/*
>  	 * Tell the memory management that we're a "memory allocator",
> @@ -7311,13 +7307,15 @@ void __meminit kswapd_run(int nid)
>  
>  	pgdat_kswapd_lock(pgdat);
>  	if (!pgdat->kswapd) {
> -		pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
> +		pgdat->kswapd = kthread_create_on_node(kswapd, pgdat, nid, "kswapd%d", nid);
>  		if (IS_ERR(pgdat->kswapd)) {
>  			/* failure at boot is fatal */
>  			pr_err("Failed to start kswapd on node %d，ret=%ld\n",
>  				   nid, PTR_ERR(pgdat->kswapd));
>  			BUG_ON(system_state < SYSTEM_RUNNING);
>  			pgdat->kswapd = NULL;
> +		} else {
> +			wake_up_process(pgdat->kswapd);
>  		}
>  	}
>  	pgdat_kswapd_unlock(pgdat);
> -- 
> 2.46.0
diff mbox series

Patch

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bd489c1af228..00a7f1e92447 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -7139,10 +7139,6 @@  static int kswapd(void *p)
 	unsigned int highest_zoneidx = MAX_NR_ZONES - 1;
 	pg_data_t *pgdat = (pg_data_t *)p;
 	struct task_struct *tsk = current;
-	const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
-
-	if (!cpumask_empty(cpumask))
-		set_cpus_allowed_ptr(tsk, cpumask);
 
 	/*
 	 * Tell the memory management that we're a "memory allocator",
@@ -7311,13 +7307,15 @@  void __meminit kswapd_run(int nid)
 
 	pgdat_kswapd_lock(pgdat);
 	if (!pgdat->kswapd) {
-		pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
+		pgdat->kswapd = kthread_create_on_node(kswapd, pgdat, nid, "kswapd%d", nid);
 		if (IS_ERR(pgdat->kswapd)) {
 			/* failure at boot is fatal */
 			pr_err("Failed to start kswapd on node %d，ret=%ld\n",
 				   nid, PTR_ERR(pgdat->kswapd));
 			BUG_ON(system_state < SYSTEM_RUNNING);
 			pgdat->kswapd = NULL;
+		} else {
+			wake_up_process(pgdat->kswapd);
 		}
 	}
 	pgdat_kswapd_unlock(pgdat);