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From:   Vlastimil Babka <vbabka@suse.cz>
To:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Christoph Lameter <cl@linux.com>,
        David Rientjes <rientjes@google.com>,
        Pekka Enberg <penberg@kernel.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc:     Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Mel Gorman <mgorman@techsingularity.net>,
        Jesper Dangaard Brouer <brouer@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Jann Horn <jannh@google.com>, Vlastimil Babka <vbabka@suse.cz>
Subject: [RFC 21/26] mm, slub: detach whole partial list at once in unfreeze_partials()
Date:   Tue, 25 May 2021 01:39:41 +0200
Message-Id: <20210524233946.20352-22-vbabka@suse.cz>
In-Reply-To: <20210524233946.20352-1-vbabka@suse.cz>
References: <20210524233946.20352-1-vbabka@suse.cz>
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Precedence: bulk

Instead of iterating through the live percpu partial list, detach it from the
kmem_cache_cpu at once. This is simpler and will allow further optimization.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
 mm/slub.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 33c3faacf7b1..414cc621d655 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2312,16 +2312,20 @@ static void unfreeze_partials(struct kmem_cache *s,
 {
 #ifdef CONFIG_SLUB_CPU_PARTIAL
 	struct kmem_cache_node *n = NULL, *n2 = NULL;
-	struct page *page, *discard_page = NULL;
+	struct page *page, *partial_page, *discard_page = NULL;
 	unsigned long flags;
 
 	local_irq_save(flags);
 
-	while ((page = slub_percpu_partial(c))) {
+	partial_page = slub_percpu_partial(c);
+	c->partial = NULL;
+
+	while (partial_page) {
 		struct page new;
 		struct page old;
 
-		slub_set_percpu_partial(c, page);
+		page = partial_page;
+		partial_page = page->next;
 
 		n2 = get_node(s, page_to_nid(page));
 		if (n != n2) {
-- 
2.31.1