From patchwork Thu Feb 14 23:01:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Ignatov X-Patchwork-Id: 1042489 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.b="fae5MsPJ"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 440sP50lZdz9s4Z for ; Fri, 15 Feb 2019 10:02:49 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387744AbfBNXCr (ORCPT ); Thu, 14 Feb 2019 18:02:47 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:58150 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728203AbfBNXB4 (ORCPT ); Thu, 14 Feb 2019 18:01:56 -0500 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1EMwQrc030451 for ; Thu, 14 Feb 2019 15:01:55 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=TwqCwOu1CBmG5YhrAFZouRSFSacswuyjBRRtsbuTlSY=; b=fae5MsPJ18poOwSnGSY7tQXnkCVsc04AnDC3W+AGZ5yI+oMMbf8TsfdRhIJFGx3tnZCv Qib7wuFpg0N9qonmQaiaRTKM7APSKLRWBWkFRi6gUnZDbR7yYm6/AzgDZGtcRHiipmVM HfhYh0wjKRk6NdOdcAPSBLIXZjmN+SJZppk= Received: from maileast.thefacebook.com ([199.201.65.23]) by mx0a-00082601.pphosted.com with ESMTP id 2qnepsgm8f-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Thu, 14 Feb 2019 15:01:55 -0800 Received: from mx-out.facebook.com (2620:10d:c0a1:3::13) by mail.thefacebook.com (2620:10d:c021:18::176) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1531.3; Thu, 14 Feb 2019 15:01:53 -0800 Received: by dev082.prn2.facebook.com (Postfix, from userid 572249) id B0C923701A76; Thu, 14 Feb 2019 15:01:52 -0800 (PST) Smtp-Origin-Hostprefix: dev From: Andrey Ignatov Smtp-Origin-Hostname: dev082.prn2.facebook.com To: CC: Andrey Ignatov , , , Smtp-Origin-Cluster: prn2c23 Subject: [PATCH bpf-next 1/2] libbpf: Introduce bpf_map__resize Date: Thu, 14 Feb 2019 15:01:42 -0800 Message-ID: <36151c3c82144ee3f68780e98ccb29a8c6ac3f75.1550185216.git.rdna@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-02-14_12:, , signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add bpf_map__resize() to change max_entries for a map. Quite often necessary map size is unknown at compile time and can be calculated only at run time. Currently the following approach is used to do so: * bpf_object__open_buffer() to open Elf file from a buffer; * bpf_object__find_map_by_name() to find relevant map; * bpf_map__def() to get map attributes and create struct bpf_create_map_attr from them; * update max_entries in bpf_create_map_attr; * bpf_create_map_xattr() to create new map with updated max_entries; * bpf_map__reuse_fd() to replace the map in bpf_object with newly created one. And after all this bpf_object can finally be loaded. The map will have new size. It 1) is quite a lot of steps; 2) doesn't take BTF into account. For "2)" even more steps should be made and some of them require changes to libbpf (e.g. to get struct btf * from bpf_object). Instead the whole problem can be solved by introducing simple bpf_map__resize() API that checks the map and sets new max_entries if the map is not loaded yet. So the new steps are: * bpf_object__open_buffer() to open Elf file from a buffer; * bpf_object__find_map_by_name() to find relevant map; * bpf_map__resize() to update max_entries. That's much simpler and works with BTF. Signed-off-by: Andrey Ignatov Acked-by: Yonghong Song --- tools/lib/bpf/libbpf.c | 14 ++++++++++++++ tools/lib/bpf/libbpf.h | 1 + tools/lib/bpf/libbpf.map | 1 + 3 files changed, 16 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e3c39edfb9d3..690e7b079202 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1114,6 +1114,20 @@ int bpf_map__reuse_fd(struct bpf_map *map, int fd) return -errno; } +int bpf_map__resize(struct bpf_map *map, __u32 max_entries) +{ + if (!map || !max_entries) + return -EINVAL; + + /* If map already created, its attributes can't be changed. */ + if (map->fd >= 0) + return -EBUSY; + + map->def.max_entries = max_entries; + + return 0; +} + static int bpf_object__probe_name(struct bpf_object *obj) { diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 69a7c25eaccc..987fd92661d6 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -294,6 +294,7 @@ LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv, bpf_map_clear_priv_t clear_priv); LIBBPF_API void *bpf_map__priv(struct bpf_map *map); LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); +LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries); LIBBPF_API bool bpf_map__is_offload_neutral(struct bpf_map *map); LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 5fc8222209f8..16f342c3d4bc 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -130,6 +130,7 @@ LIBBPF_0.0.2 { bpf_probe_helper; bpf_probe_map_type; bpf_probe_prog_type; + bpf_map__resize; bpf_map_lookup_elem_flags; bpf_object__find_map_fd_by_name; bpf_get_link_xdp_id;