linux-kernel - [PATCH 16/21] mm: Create/affine kswapd to its preferred node

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241112142248.20503-17-frederic@kernel.org>
Date: Tue, 12 Nov 2024 15:22:40 +0100
From: Frederic Weisbecker <frederic@...nel.org>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Frederic Weisbecker <frederic@...nel.org>,
	Michal Hocko <mhocko@...nel.org>,
	Vlastimil Babka <vbabka@...e.cz>,
	linux-mm@...ck.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Michal Hocko <mhocko@...e.com>
Subject: [PATCH 16/21] mm: Create/affine kswapd to its preferred node

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@...e.cz>
Acked-by: Michal Hocko <mhocko@...e.com>
Signed-off-by: Frederic Weisbecker <frederic@...nel.org>
---
 mm/vmscan.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 28ba2b06fc7d..5d7686bef51c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -7168,10 +7168,6 @@ 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",
@@ -7340,13 +7336,15 @@ 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