netdev - [PATCH v2 bpf-next 09/13] bpf: Allow reuse from waiting_for_gp

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Message-Id: <20230624031333.96597-10-alexei.starovoitov@gmail.com>
Date: Fri, 23 Jun 2023 20:13:29 -0700
From: Alexei Starovoitov <alexei.starovoitov@...il.com>
To: daniel@...earbox.net,
	andrii@...nel.org,
	void@...ifault.com,
	houtao@...weicloud.com,
	paulmck@...nel.org
Cc: tj@...nel.org,
	rcu@...r.kernel.org,
	netdev@...r.kernel.org,
	bpf@...r.kernel.org,
	kernel-team@...com
Subject: [PATCH v2 bpf-next 09/13] bpf: Allow reuse from waiting_for_gp_ttrace list.

From: Alexei Starovoitov <ast@...nel.org>

alloc_bulk() can reuse elements from free_by_rcu_ttrace.
Let it reuse from waiting_for_gp_ttrace as well to avoid unnecessary kmalloc().

Signed-off-by: Alexei Starovoitov <ast@...nel.org>
---
 kernel/bpf/memalloc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index 692a9a30c1dc..666917c16e87 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -203,6 +203,15 @@ static void alloc_bulk(struct bpf_mem_cache *c, int cnt, int node)
 	if (i >= cnt)
 		return;
 
+	for (; i < cnt; i++) {
+		obj = llist_del_first(&c->waiting_for_gp_ttrace);
+		if (!obj)
+			break;
+		add_obj_to_free_list(c, obj);
+	}
+	if (i >= cnt)
+		return;
+
 	memcg = get_memcg(c);
 	old_memcg = set_active_memcg(memcg);
 	for (; i < cnt; i++) {
-- 
2.34.1