From patchwork Wed Oct 19 11:55:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13011666 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1751C433FE for ; Wed, 19 Oct 2022 12:12:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232841AbiJSMMH (ORCPT ); Wed, 19 Oct 2022 08:12:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232769AbiJSMLl (ORCPT ); Wed, 19 Oct 2022 08:11:41 -0400 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC23C1633BF for ; Wed, 19 Oct 2022 04:46:39 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4MspPM4nPJzl7bs for ; Wed, 19 Oct 2022 19:27:51 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgAXCzKu309jwb9lAA--.56298S6; Wed, 19 Oct 2022 19:29:53 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org, Alexei Starovoitov Cc: Martin KaFai Lau , Andrii Nakryiko , Song Liu , Hao Luo , Yonghong Song , Daniel Borkmann , KP Singh , Stanislav Fomichev , Jiri Olsa , John Fastabend , houtao1@huawei.com Subject: [PATCH bpf 2/2] bpf: Use __llist_del_all() whenever possbile during memory draining Date: Wed, 19 Oct 2022 19:55:39 +0800 Message-Id: <20221019115539.983394-3-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20221019115539.983394-1-houtao@huaweicloud.com> References: <20221019115539.983394-1-houtao@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgAXCzKu309jwb9lAA--.56298S6 X-Coremail-Antispam: 1UD129KBjvJXoW7uw1ruF1kAw13Wry3tr1fJFb_yoW8WF1rpF W3Cry8Jr48AF929a1Utwn3ur95Xw4rGay3G3yUua4akr1rXwsrtrWxCw1jgFy3urW0q343 CryvgF1xWF4UXa7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUB0b4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2Ij64 vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8G jcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2I x0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK 8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I 0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxUFa9-UUUUU X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao Except for waiting_for_gp list, there are no concurrent operations on free_by_rcu, free_llist and free_llist_extra lists, so use __llist_del_all() instead of llist_del_all(). waiting_for_gp list can be deleted by RCU callback concurrently, so still use llist_del_all(). Signed-off-by: Hou Tao Acked-by: Stanislav Fomichev --- kernel/bpf/memalloc.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index 48e606aaacf0..7f45744a09f7 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -422,14 +422,17 @@ static void drain_mem_cache(struct bpf_mem_cache *c) /* No progs are using this bpf_mem_cache, but htab_map_free() called * bpf_mem_cache_free() for all remaining elements and they can be in * free_by_rcu or in waiting_for_gp lists, so drain those lists now. + * + * Except for waiting_for_gp list, there are no concurrent operations + * on these lists, so it is safe to use __llist_del_all(). */ llist_for_each_safe(llnode, t, __llist_del_all(&c->free_by_rcu)) free_one(c, llnode); llist_for_each_safe(llnode, t, llist_del_all(&c->waiting_for_gp)) free_one(c, llnode); - llist_for_each_safe(llnode, t, llist_del_all(&c->free_llist)) + llist_for_each_safe(llnode, t, __llist_del_all(&c->free_llist)) free_one(c, llnode); - llist_for_each_safe(llnode, t, llist_del_all(&c->free_llist_extra)) + llist_for_each_safe(llnode, t, __llist_del_all(&c->free_llist_extra)) free_one(c, llnode); }