linux-kernel - [PATCH v3 2/3] debugobjects: Use hlist_splice

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: <20240911083521.2257-3-thunder.leizhen@huawei.com>
Date: Wed, 11 Sep 2024 16:35:20 +0800
From: Zhen Lei <thunder.leizhen@...wei.com>
To: Andrew Morton <akpm@...ux-foundation.org>, Thomas Gleixner
	<tglx@...utronix.de>, <linux-kernel@...r.kernel.org>
CC: Zhen Lei <thunder.leizhen@...wei.com>
Subject: [PATCH v3 2/3] debugobjects: Use hlist_splice_init() to reduce lock conflicts

The newly allocated debug_obj control blocks can be concatenated into a
sub list in advance outside the lock, so that the operation time inside
the lock can be reduced and the possibility of lock conflict can be
reduced.

Signed-off-by: Zhen Lei <thunder.leizhen@...wei.com>
---
 lib/debugobjects.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index df48acc5d4b34fc..19a91c6bc67eb9c 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -161,23 +161,25 @@ static void fill_pool(void)
 		return;
 
 	while (READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) {
-		struct debug_obj *new[ODEBUG_BATCH_SIZE];
+		struct debug_obj *new, *last = NULL;
+		HLIST_HEAD(freelist);
 		int cnt;
 
 		for (cnt = 0; cnt < ODEBUG_BATCH_SIZE; cnt++) {
-			new[cnt] = kmem_cache_zalloc(obj_cache, gfp);
-			if (!new[cnt])
+			new = kmem_cache_zalloc(obj_cache, gfp);
+			if (!new)
 				break;
+			hlist_add_head(&new->node, &freelist);
+			if (!last)
+				last = new;
 		}
 		if (!cnt)
 			return;
 
 		raw_spin_lock_irqsave(&pool_lock, flags);
-		while (cnt) {
-			hlist_add_head(&new[--cnt]->node, &obj_pool);
-			debug_objects_allocated++;
-			WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
-		}
+		hlist_splice_init(&freelist, &last->node, &obj_pool);
+		debug_objects_allocated += cnt;
+		WRITE_ONCE(obj_pool_free, obj_pool_free + cnt);
 		raw_spin_unlock_irqrestore(&pool_lock, flags);
 	}
 }
-- 
2.34.1