From patchwork Fri Nov 1 14:23:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tonghao Zhang X-Patchwork-Id: 1188084 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=openvswitch.org (client-ip=140.211.169.12; helo=mail.linuxfoundation.org; envelope-from=ovs-dev-bounces@openvswitch.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="VhXfJh+N"; dkim-atps=neutral Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 474PgY1Q8wz9sP4 for ; Sat, 2 Nov 2019 01:28:25 +1100 (AEDT) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 6B3271923; Fri, 1 Nov 2019 14:24:25 +0000 (UTC) X-Original-To: dev@openvswitch.org Delivered-To: ovs-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 5AC5418AB for ; Fri, 1 Nov 2019 14:24:24 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-pf1-f193.google.com (mail-pf1-f193.google.com [209.85.210.193]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id C7A6C14D for ; Fri, 1 Nov 2019 14:24:23 +0000 (UTC) Received: by mail-pf1-f193.google.com with SMTP id d13so7203996pfq.2 for ; Fri, 01 Nov 2019 07:24:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=+6y7OChHTvMPWpmBp1Ktoa0+GosQY6LfAXE2ork61rA=; b=VhXfJh+N4bmOKZLDKZ65/HcyEtHvXWWpYHsNmI4lli4UAcZgGcn2IlNO6sZyNLFmIA +Wh/P6hhELu5bh1cMHMRzoiH0XjEoOyd5LC1LNiCDS8Kd5TRBA6unCVS3PxOnZdd9PoT IO0NNZRnEnTJQmKrfKOQzUj6aECH/tEbw+ugG5GzT327hJ+8vpGiKJZKjEK2MwJNY1no Ag18wgB7tKCx67w0Iqb1yMxgaqT9ZmPtdE1qhLbmT5tuZ1BKXkAPJzU+uQhbXC8i6dXX 3zyZhhO159+K28wwTOgawnCtI6TCB9L5cMDUJAm/QfBiV0plDRyoEHLXgvkFGrssFp+O 2E9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=+6y7OChHTvMPWpmBp1Ktoa0+GosQY6LfAXE2ork61rA=; b=qwQFszkQ3pI30gngWt6pyppxsRP4NEQprdTfUSeOKEeZndGEMJMLLZQ1fZe4lLu/BT rlJhmPlB3/Nfg2Hf5zGn1WJf7GUTJyzAzWkY1o5JqLMI4En3wXLpcZM5t2qfcCc5CD9Q m14Yi+8Ioo0BzhnzbcqTfdPPS95JBuFCfjLjj3Xo8aHHOl0m792LWmZ0I4mO2eNtacuh oMU+Nfs7SmcI0qsLiQ2oHVYZgML5zzAmZKdwd01ak7QZVXvjcUs7HuG4F8MmSfnWYKWO 9vxujHb2117EZvTdnYPhi54UwhbcEjK9K0ZhFWBuRIu4VhdD3Fm18Oi1f27T4kQA7oiS KlEw== X-Gm-Message-State: APjAAAVO3gzrW5Pvx3cFmHGKhyvarkLtWesr+fVuXHnXnbGJDaaTeVGy 7u/9P3ABrysb+6Sg/u/YLfY= X-Google-Smtp-Source: APXvYqzkEh4hxpliGiW8ZaZM8eTAEPuQW/LzHyotTlB67yYhCz8Nt1rpooXNpiOMsJJg+6NeKNJvqQ== X-Received: by 2002:a17:90b:3105:: with SMTP id gc5mr4361862pjb.30.1572618263399; Fri, 01 Nov 2019 07:24:23 -0700 (PDT) Received: from local.opencloud.tech.localdomain ([1.203.173.208]) by smtp.gmail.com with ESMTPSA id c12sm8296499pfp.67.2019.11.01.07.24.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Nov 2019 07:24:22 -0700 (PDT) From: xiangxia.m.yue@gmail.com To: gvrose8192@gmail.com, pshelar@ovn.org, davem@davemloft.net Date: Fri, 1 Nov 2019 22:23:49 +0800 Message-Id: <1572618234-6904-6-git-send-email-xiangxia.m.yue@gmail.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1572618234-6904-1-git-send-email-xiangxia.m.yue@gmail.com> References: <1572618234-6904-1-git-send-email-xiangxia.m.yue@gmail.com> X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: dev@openvswitch.org, netdev@vger.kernel.org Subject: [ovs-dev] [PATCH net-next v6 05/10] net: openvswitch: optimize flow-mask looking up X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ovs-dev-bounces@openvswitch.org Errors-To: ovs-dev-bounces@openvswitch.org From: Tonghao Zhang The full looking up on flow table traverses all mask array. If mask-array is too large, the number of invalid flow-mask increase, performance will be drop. One bad case, for example: M means flow-mask is valid and NULL of flow-mask means deleted. +-------------------------------------------+ | M | NULL | ... | NULL | M| +-------------------------------------------+ In that case, without this patch, openvswitch will traverses all mask array, because there will be one flow-mask in the tail. This patch changes the way of flow-mask inserting and deleting, and the mask array will be keep as below: there is not a NULL hole. In the fast path, we can "break" "for" (not "continue") in flow_lookup when we get a NULL flow-mask. "break" v +-------------------------------------------+ | M | M | NULL |... | NULL | NULL| +-------------------------------------------+ This patch don't optimize slow or control path, still using ma->max to traverse. Slow path: * tbl_mask_array_realloc * ovs_flow_tbl_lookup_exact * flow_mask_find Signed-off-by: Tonghao Zhang Tested-by: Greg Rose Acked-by: Pravin B Shelar --- net/openvswitch/flow_table.c | 104 ++++++++++++++++++++++--------------------- 1 file changed, 53 insertions(+), 51 deletions(-) diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c index c7ba435..a10d421 100644 --- a/net/openvswitch/flow_table.c +++ b/net/openvswitch/flow_table.c @@ -518,8 +518,8 @@ static struct sw_flow *flow_lookup(struct flow_table *tbl, u32 *n_mask_hit, u32 *index) { - struct sw_flow_mask *mask; struct sw_flow *flow; + struct sw_flow_mask *mask; int i; if (*index < ma->max) { @@ -538,7 +538,7 @@ static struct sw_flow *flow_lookup(struct flow_table *tbl, mask = rcu_dereference_ovsl(ma->masks[i]); if (!mask) - continue; + break; flow = masked_flow_lookup(ti, key, mask, n_mask_hit); if (flow) { /* Found */ @@ -695,8 +695,7 @@ struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl, int ovs_flow_tbl_num_masks(const struct flow_table *table) { struct mask_array *ma = rcu_dereference_ovsl(table->mask_array); - - return ma->count; + return READ_ONCE(ma->count); } static struct table_instance *table_instance_expand(struct table_instance *ti, @@ -705,21 +704,33 @@ static struct table_instance *table_instance_expand(struct table_instance *ti, return table_instance_rehash(ti, ti->n_buckets * 2, ufid); } -static void tbl_mask_array_delete_mask(struct mask_array *ma, - struct sw_flow_mask *mask) +static void tbl_mask_array_del_mask(struct flow_table *tbl, + struct sw_flow_mask *mask) { - int i; + struct mask_array *ma = ovsl_dereference(tbl->mask_array); + int i, ma_count = READ_ONCE(ma->count); /* Remove the deleted mask pointers from the array */ - for (i = 0; i < ma->max; i++) { - if (mask == ovsl_dereference(ma->masks[i])) { - RCU_INIT_POINTER(ma->masks[i], NULL); - ma->count--; - kfree_rcu(mask, rcu); - return; - } + for (i = 0; i < ma_count; i++) { + if (mask == ovsl_dereference(ma->masks[i])) + goto found; } + BUG(); + return; + +found: + WRITE_ONCE(ma->count, ma_count -1); + + rcu_assign_pointer(ma->masks[i], ma->masks[ma_count -1]); + RCU_INIT_POINTER(ma->masks[ma_count -1], NULL); + + kfree_rcu(mask, rcu); + + /* Shrink the mask array if necessary. */ + if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) && + ma_count <= (ma->max / 3)) + tbl_mask_array_realloc(tbl, ma->max / 2); } /* Remove 'mask' from the mask list, if it is not needed any more. */ @@ -733,17 +744,8 @@ static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask) BUG_ON(!mask->ref_count); mask->ref_count--; - if (!mask->ref_count) { - struct mask_array *ma; - - ma = ovsl_dereference(tbl->mask_array); - tbl_mask_array_delete_mask(ma, mask); - - /* Shrink the mask array if necessary. */ - if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) && - ma->count <= (ma->max / 3)) - tbl_mask_array_realloc(tbl, ma->max / 2); - } + if (!mask->ref_count) + tbl_mask_array_del_mask(tbl, mask); } } @@ -807,6 +809,29 @@ static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl, return NULL; } +static int tbl_mask_array_add_mask(struct flow_table *tbl, + struct sw_flow_mask *new) +{ + struct mask_array *ma = ovsl_dereference(tbl->mask_array); + int err, ma_count = READ_ONCE(ma->count); + + if (ma_count >= ma->max) { + err = tbl_mask_array_realloc(tbl, ma->max + + MASK_ARRAY_SIZE_MIN); + if (err) + return err; + + ma = ovsl_dereference(tbl->mask_array); + } + + BUG_ON(ovsl_dereference(ma->masks[ma_count])); + + rcu_assign_pointer(ma->masks[ma_count], new); + WRITE_ONCE(ma->count, ma_count +1); + + return 0; +} + /* Add 'mask' into the mask list, if it is not already there. */ static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow, const struct sw_flow_mask *new) @@ -815,9 +840,6 @@ static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow, mask = flow_mask_find(tbl, new); if (!mask) { - struct mask_array *ma; - int i; - /* Allocate a new mask if none exsits. */ mask = mask_alloc(); if (!mask) @@ -826,29 +848,9 @@ static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow, mask->range = new->range; /* Add mask to mask-list. */ - ma = ovsl_dereference(tbl->mask_array); - if (ma->count >= ma->max) { - int err; - - err = tbl_mask_array_realloc(tbl, ma->max + - MASK_ARRAY_SIZE_MIN); - if (err) { - kfree(mask); - return err; - } - - ma = ovsl_dereference(tbl->mask_array); - } - - for (i = 0; i < ma->max; i++) { - const struct sw_flow_mask *t; - - t = ovsl_dereference(ma->masks[i]); - if (!t) { - rcu_assign_pointer(ma->masks[i], mask); - ma->count++; - break; - } + if (tbl_mask_array_add_mask(tbl, mask)) { + kfree(mask); + return -ENOMEM; } } else { BUG_ON(!mask->ref_count);