From patchwork Fri Oct 20 13:31:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13430736 X-Patchwork-Delegate: bpf@iogearbox.net 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 D54311BDD4 for ; Fri, 20 Oct 2023 13:31:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 320CD19E for ; Fri, 20 Oct 2023 06:30:59 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4SBlpN5Kwxz4f3mHm for ; Fri, 20 Oct 2023 21:30:52 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgBn+dgIgTJlmYjjDQ--.7231S6; Fri, 20 Oct 2023 21:30:55 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org, linux-mm@kvack.org Cc: Martin KaFai Lau , Alexei Starovoitov , Andrii Nakryiko , Song Liu , Hao Luo , Yonghong Song , Daniel Borkmann , KP Singh , Stanislav Fomichev , Jiri Olsa , John Fastabend , houtao1@huawei.com, Dennis Zhou , Tejun Heo , Christoph Lameter , Andrew Morton Subject: [PATCH bpf-next v3 2/7] mm/percpu.c: introduce pcpu_alloc_size() Date: Fri, 20 Oct 2023 21:31:57 +0800 Message-Id: <20231020133202.4043247-3-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20231020133202.4043247-1-houtao@huaweicloud.com> References: <20231020133202.4043247-1-houtao@huaweicloud.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgBn+dgIgTJlmYjjDQ--.7231S6 X-Coremail-Antispam: 1UD129KBjvJXoW7Aw13Xr4kXw1kZFyUur15urg_yoW5JFy3pF Wkuryrtr48Xrn7Ww1ft3WUZw4rWw4kWF4xJay3WFy3Zr1aqFyYgr1qyrW5uFyrGFn2vr12 qrZ0qFWxCFW5J3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBFb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2Ij64 vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8G jcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF0xvE2I x0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4UJwCI42IY6xAI w20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x 0267AKxVW8Jr0_Cr1UYxBIdaVFxhVjvjDU0xZFpf9x07UC9aPUUUUU= X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao Introduce pcpu_alloc_size() to get the size of the dynamic per-cpu area. It will be used by bpf memory allocator in the following patches. BPF memory allocator maintains per-cpu area caches for multiple area sizes and its free API only has the to-be-freed per-cpu pointer, so it needs the size of dynamic per-cpu area to select the corresponding cache when bpf program frees the dynamic per-cpu pointer. Acked-by: Dennis Zhou Signed-off-by: Hou Tao --- include/linux/percpu.h | 1 + mm/percpu.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 68fac2e7cbe67..8c677f185901b 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -132,6 +132,7 @@ extern void __init setup_per_cpu_areas(void); extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) __alloc_size(1); extern void __percpu *__alloc_percpu(size_t size, size_t align) __alloc_size(1); extern void free_percpu(void __percpu *__pdata); +extern size_t pcpu_alloc_size(void __percpu *__pdata); DEFINE_FREE(free_percpu, void __percpu *, free_percpu(_T)) diff --git a/mm/percpu.c b/mm/percpu.c index 76b9c5e63c562..1759b91c8944a 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -2244,6 +2244,37 @@ static void pcpu_balance_workfn(struct work_struct *work) mutex_unlock(&pcpu_alloc_mutex); } +/** + * pcpu_alloc_size - the size of the dynamic percpu area + * @ptr: pointer to the dynamic percpu area + * + * Returns the size of the @ptr allocation. This is undefined for statically + * defined percpu variables as there is no corresponding chunk->bound_map. + * + * RETURNS: + * The size of the dynamic percpu area. + * + * CONTEXT: + * Can be called from atomic context. + */ +size_t pcpu_alloc_size(void __percpu *ptr) +{ + struct pcpu_chunk *chunk; + unsigned long bit_off, end; + void *addr; + + if (!ptr) + return 0; + + addr = __pcpu_ptr_to_addr(ptr); + /* No pcpu_lock here: ptr has not been freed, so chunk is still alive */ + chunk = pcpu_chunk_addr_search(addr); + bit_off = (addr - chunk->base_addr) / PCPU_MIN_ALLOC_SIZE; + end = find_next_bit(chunk->bound_map, pcpu_chunk_map_bits(chunk), + bit_off + 1); + return (end - bit_off) * PCPU_MIN_ALLOC_SIZE; +} + /** * free_percpu - free percpu area * @ptr: pointer to area to free