From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C7117F; Fri, 7 Jul 2023 01:45:22 +0000 (UTC) Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA7D91BDB; Thu, 6 Jul 2023 18:45:20 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4Qxx6j1vs1z4f3jYq; Fri, 7 Jul 2023 09:45:17 +0800 (CST) Received: from [10.174.176.117] (unknown [10.174.176.117]) by APP1 (Coremail) with SMTP id cCh0CgBHZjArbqdkkI6mMg--.50539S2; Fri, 07 Jul 2023 09:45:17 +0800 (CST) Subject: Re: [PATCH v4 bpf-next 12/14] bpf: Introduce bpf_mem_free_rcu() similar to kfree_rcu(). To: Alexei Starovoitov Cc: tj@kernel.org, rcu@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com, daniel@iogearbox.net, andrii@kernel.org, void@manifault.com, paulmck@kernel.org References: <20230706033447.54696-1-alexei.starovoitov@gmail.com> <20230706033447.54696-13-alexei.starovoitov@gmail.com> From: Hou Tao Message-ID: <2c09b7d7-b91c-c561-3fd6-b8483aab01dc@huaweicloud.com> Date: Fri, 7 Jul 2023 09:45:15 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20230706033447.54696-13-alexei.starovoitov@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-CM-TRANSID:cCh0CgBHZjArbqdkkI6mMg--.50539S2 X-Coremail-Antispam: 1UD129KBjvdXoWruryfGw1fJF1UJFyUKF48JFb_yoWfJwb_WF WkXF1rAr47GFWvqw1rCF4xAa15G3W5Ja409ry5XFyDGF15Wr98AF4xXry3Aayktw4SqF1U J34rJa1DKrnxZjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbI8YFVCjjxCrM7AC8VAFwI0_Gr0_Xr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwV A0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x02 67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I 0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7I2V7IY0VAS 07AlzVAYIcxG8wCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c 02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_ GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7 CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6Fyj6rWUJwCI42IY6I8E87Iv67AK xVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvj xUOyCJDUUUU X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,NICE_REPLY_A, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On 7/6/2023 11:34 AM, Alexei Starovoitov wrote: > From: Alexei Starovoitov > > Introduce bpf_mem_[cache_]free_rcu() similar to kfree_rcu(). > Unlike bpf_mem_[cache_]free() that links objects for immediate reuse into > per-cpu free list the _rcu() flavor waits for RCU grace period and then moves > objects into free_by_rcu_ttrace list where they are waiting for RCU > task trace grace period to be freed into slab. > > The life cycle of objects: > alloc: dequeue free_llist > free: enqeueu free_llist > free_rcu: enqueue free_by_rcu -> waiting_for_gp > free_llist above high watermark -> free_by_rcu_ttrace > after RCU GP waiting_for_gp -> free_by_rcu_ttrace > free_by_rcu_ttrace -> waiting_for_gp_ttrace -> slab > > Signed-off-by: Alexei Starovoitov Acked-by: Hou Tao