From patchwork Tue Oct 15 10:30:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tonghao Zhang X-Patchwork-Id: 1177889 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="i+35rjY/"; 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 46tXKm4nQfz9sPJ for ; Wed, 16 Oct 2019 23:53:48 +1100 (AEDT) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 0A28FE27; Wed, 16 Oct 2019 12:50:45 +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 D448ADBB for ; Wed, 16 Oct 2019 12:50:43 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-pg1-f196.google.com (mail-pg1-f196.google.com [209.85.215.196]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id C52E413A for ; Wed, 16 Oct 2019 12:50:42 +0000 (UTC) Received: by mail-pg1-f196.google.com with SMTP id r1so13056988pgj.12 for ; Wed, 16 Oct 2019 05:50:42 -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=0leZDpps0K0dtZHi+cGtthWfpv7itMdBdkx/LWqMEjg=; b=i+35rjY/kjPpTi/s5bPvlN+0/Y5I1sddG4cGEdC6WJcHth2tgsSa/LtP50RAuPZyZ1 WFo5o95WvSDM4xWYfM6pVZe0vxX3ZCiHVVfcEJJfGmTTYfRmjSIjNuRSpMRtCxJMPyhh sEQHkL4Cm0/UELghNz/qbkhqE7qEEufdLzxQx9+jSkACrf191aEYfdUNxBxEfKNPBLot TharcJwUTvAauD1z2qc3J16WgTXa8abhPMIp9tD06wSKMrEMVj5mWiBMIHUF7rffrzqs KKS9FisJThqIjrBQ97wmhp5VsnzU3XDWGqeZl7PMS1zVQ0OcP/lQMUfAXXYE4avnE/DJ FfTw== 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=0leZDpps0K0dtZHi+cGtthWfpv7itMdBdkx/LWqMEjg=; b=HLuTHAwjrIhtzzIg2XxkWbPNOFTLyvTdlKSWyq0d2hfYLqe1ou9O+1p46oDqpGnXD4 OKBQ77ee7UUNeT8KroO2Grfnv0ebmfv8jk0arZeiWNqCXSC8cmhPNJQ6RG4S+cbh2UZS 8A8N08nfY4kRElLRfrj2Tj/R9ZQCDlolEXGZYKKDy7mLYh+afUzq42vVWqkN0Il2Ias8 nXAU0h+1/mhoNVqqneUBKjqU498MA1UQFQPGeD+HRUVvaTN0J0vYCVLot4hb+n9tq7YK dYjSTAJn5wEHXxbXUjVmHer9Zc5Qzjfv9akBtkeoEIDOaT+0VMki+CTsk/SiVUcD0KYa +vHQ== X-Gm-Message-State: APjAAAXe7Z7rVjazpJbjWca3y0zxcLARmKRE5+WZSt+c4Y1jGhw1jhKC v/NoGyNwUpP7uyne4Z57uVWqttrK X-Google-Smtp-Source: APXvYqz3KK3A8jV0U/02f5pVmYdlMD7ptt0rPN58mWRcrIka2hYLUIERyV16zOzEWciw6+E9ApfEnQ== X-Received: by 2002:aa7:87ca:: with SMTP id i10mr44864834pfo.62.1571230242333; Wed, 16 Oct 2019 05:50:42 -0700 (PDT) Received: from local.opencloud.tech.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id d19sm2747339pjz.5.2019.10.16.05.50.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 16 Oct 2019 05:50:41 -0700 (PDT) From: xiangxia.m.yue@gmail.com To: gvrose8192@gmail.com, pshelar@ovn.org Date: Tue, 15 Oct 2019 18:30:35 +0800 Message-Id: <1571135440-24313-6-git-send-email-xiangxia.m.yue@gmail.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1571135440-24313-1-git-send-email-xiangxia.m.yue@gmail.com> References: <1571135440-24313-1-git-send-email-xiangxia.m.yue@gmail.com> X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00, DATE_IN_PAST_24_48, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE autolearn=no 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 v4 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 --- net/openvswitch/flow_table.c | 101 ++++++++++++++++++++++--------------------- 1 file changed, 52 insertions(+), 49 deletions(-) diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c index 8d4f50d..a10d421 100644 --- a/net/openvswitch/flow_table.c +++ b/net/openvswitch/flow_table.c @@ -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 */ @@ -695,7 +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, @@ -704,21 +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. */ @@ -732,17 +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); } } @@ -806,6 +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) @@ -814,9 +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) @@ -825,29 +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);