From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f66.google.com (mail-wm1-f66.google.com [209.85.128.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 86C4B12FF90; Thu, 7 Mar 2024 17:12:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.66 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709831579; cv=none; b=X34pnndo0uQQrISpLGB+5T1ibNdtsFzES4PKKxT9K062LogK5O9iG41+U3/gK+uWgZY+/9pRXhtPmyOEedMVeDaW8PlQ38eQdqAeEqgaYvsekjnyXgcohLa9kAgxAV+PHsgMXBo4f3tWliurzAxf0DTmFcrTH4cMPhMp9vn1EG8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709831579; c=relaxed/simple; bh=W/MumZVpisOIH0WGNOiLL/b9IywMSOOGhuiwYpsXbpk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tvjSHKpK69NWzO5FwB26KtS9LJZegl3WmGCF87RPS+MhcY6IxEk2MvHloHprbMVIBopwGEnCiEAu0U7newPDqnlG/YIJSgue4cDj3BBZGhFhRjAlEgR1tQO4Ufh0xlQeJnd5bd1eh9lgojv9nGii0OrB0WUMJuAOwTRr7iac428= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=gaahahW8; arc=none smtp.client-ip=209.85.128.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gaahahW8" Received: by mail-wm1-f66.google.com with SMTP id 5b1f17b1804b1-412f1961101so11000985e9.0; Thu, 07 Mar 2024 09:12:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1709831576; x=1710436376; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=y7Ai7Y640JAmBstNBPvMR7Rlw25isJH8cGZXI5luHRI=; b=gaahahW8wgYGQMKaV9v5zbhOs09Fh/KbI+R02ggg6tR0SMy77u7xS3xzqbzAiUqwEQ vo9RcfqL3d8GJc6hOzGR7fAHcaFBHNz7XnOVRPa+brp7kI6/KXMmfH6wD27+gseKRZyt ZNa/iLZqNnqJUz8BAIARKCVD8ff8lUDyPuEUsyqC8T7as/TY8FO87O8JKVbprW+ac2ll h9o/9eiMnieayMBBe4UzPe1Xv+btRVGtPBq/ZWjRH1eOE0dKU+aYryu/QURrIgvopoEU sGO4dDJs8u6IFYMGThe8GW5vg9mrAp+lMYD3oxoiZsNcBz5yNqRtU/zqvCYWxfaRBVdA LSmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709831576; x=1710436376; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=y7Ai7Y640JAmBstNBPvMR7Rlw25isJH8cGZXI5luHRI=; b=gbzHr3ag7qNJdq+eeZGMYgKnUAUxmt+3HqpvOoocqkRiwdYzzdVEs39wy+pNJ02rrU ZC7nw1mgThcBteceWvNke76NDGjLjiSxKSleVbWNGWS2x3SIj2Fo5wdYgr1NWzkgi6i2 DQhGnrfj+DiDU6KK85iHlhWuTJTO4ogUzgTNDc6moY0KGhwvQtJQIQnr4kJxKHNzkRLD 87kJBLsguuBdGgMxS5UYcRltSV3MWHoaeqSHfQ+lUdaF2RgdHgnwVOt3IKzxoYQHFEP0 cjR4FJM2mvyjzYwHd9rCxZDDb9zHku3lncUPD5Wsg0nnqeicEz8j3grIdCePcAiEnFUF RQEg== X-Forwarded-Encrypted: i=1; AJvYcCXF+nLeVupK5J4Iuuf6OM3wkUW1WO/SQiw224TBMGj5rh8sQZefiCNj5i4l3AmqhCEz+CEITq7gftd7YSRcqYY7UDkZM+NIdiBcscRg X-Gm-Message-State: AOJu0Ywb6eCVCVyeR4JR/eHzrQKDaZ6FGAJoC+07I8BOS0Gf3m7O4gGJ U6qnLR3isIcItg2J/XhevB45/LblGnOvg4zvh7h4RtCDsa6JuIt4 X-Google-Smtp-Source: AGHT+IH76QeD5yqt+yL0acN5cfjxH5a/KzxG6IU6HAzuH+a11C+gcrK6ns/w95lvnLZ+0KBoOUFbEQ== X-Received: by 2002:a05:600c:1986:b0:413:14da:a9ec with SMTP id t6-20020a05600c198600b0041314daa9ecmr621128wmq.0.1709831575873; Thu, 07 Mar 2024 09:12:55 -0800 (PST) Received: from localhost ([45.130.85.5]) by smtp.gmail.com with ESMTPSA id er15-20020a05600c84cf00b00412ff07df2bsm3168611wmb.37.2024.03.07.09.12.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Mar 2024 09:12:55 -0800 (PST) From: Leone Fernando To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, willemb@google.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Leone Fernando Subject: [PATCH net-next 2/4] net: dst_cache: add input_dst_cache API Date: Thu, 7 Mar 2024 18:12:00 +0100 Message-Id: <20240307171202.232684-3-leone4fernando@gmail.com> In-Reply-To: <20240307171202.232684-1-leone4fernando@gmail.com> References: <20240307171202.232684-1-leone4fernando@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The input_dst_cache allows fast lookup of frequently encountered dsts. In order to provide stable results, I implemented a simple linear hashtable with each bucket containing a constant amount of entries (DST_CACHE_INPUT_BUCKET_SIZE). Similarly to how the route hint is used, I defined the hashtable key to contain the daddr and the tos of the IP header. Lookup is performed in a straightforward manner: start at the bucket head corresponding the hashed key and search the following DST_CACHE_INPUT_BUCKET_SIZE entries of the array for a matching key. When inserting a new dst to the cache, if all the bucket entries are full, the oldest one is deleted to make room for the new dst. Signed-off-by: Leone Fernando --- include/net/dst_cache.h | 68 +++++++++++++++++++++ net/core/dst_cache.c | 132 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 200 insertions(+) diff --git a/include/net/dst_cache.h b/include/net/dst_cache.h index df6622a5fe98..1c3b06f08d7d 100644 --- a/include/net/dst_cache.h +++ b/include/net/dst_cache.h @@ -7,12 +7,40 @@ #if IS_ENABLED(CONFIG_IPV6) #include #endif +#include + +#define DST_CACHE_INPUT_SHIFT (9) +#define DST_CACHE_INPUT_SIZE (1 << DST_CACHE_INPUT_SHIFT) +#define DST_CACHE_INPUT_BUCKET_SIZE (4) +#define DST_CACHE_INPUT_HASH_MASK (~(DST_CACHE_INPUT_BUCKET_SIZE - 1)) +#define INVALID_DST_CACHE_INPUT_KEY (~(u64)(0)) struct dst_cache { struct dst_cache_pcpu __percpu *cache; unsigned long reset_ts; }; +extern unsigned int dst_cache_net_id __read_mostly; + +/** + * idst_for_each_in_bucket - iterate over a dst cache bucket + * @pos: the type * to use as a loop cursor + * @head: the head of the cpu dst cache. + * @hash: the hash of the bucket + */ +#define idst_for_each_in_bucket(pos, head, hash) \ + for (pos = &head[hash]; \ + pos < &head[hash + DST_CACHE_INPUT_BUCKET_SIZE]; \ + pos++) + +/** + * idst_for_each_in_cache - iterate over the dst cache + * @pos: the type * to use as a loop cursor + * @head: the head of the cpu dst cache. + */ +#define idst_for_each_in_cache(pos, head) \ + for (pos = head; pos < head + DST_CACHE_INPUT_SIZE; pos++) + /** * dst_cache_get - perform cache lookup * @dst_cache: the cache @@ -106,4 +134,44 @@ int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp); */ void dst_cache_destroy(struct dst_cache *dst_cache); +/** + * dst_cache_input_get_noref - perform lookup in the input cache, + * return a noref dst + * @dst_cache: the input cache + * @skb: the packet according to which the dst entry will be searched + * local BH must be disabled. + */ +struct dst_entry *dst_cache_input_get_noref(struct dst_cache *dst_cache, + struct sk_buff *skb); + +/** + * dst_cache_input_add - add the dst of the given skb to the input cache. + * + * in case the cache bucket is full, the oldest entry will be deleted + * and replaced with the new one. + * @dst_cache: the input cache + * @skb: The packet according to which the dst entry will be searched + * + * local BH must be disabled. + */ +void dst_cache_input_add(struct dst_cache *dst_cache, + const struct sk_buff *skb); + +/** + * dst_cache_input_init - initialize the input cache, + * allocating the required storage + */ +int __init dst_cache_input_init(void); + +static inline u64 create_dst_cache_key_ip4(const struct sk_buff *skb) +{ + struct iphdr *iphdr = ip_hdr(skb); + + return (((u64)iphdr->daddr) << 8) | iphdr->tos; +} + +static inline u32 hash_dst_cache_key(u64 key) +{ + return hash_64(key, DST_CACHE_INPUT_SHIFT) & DST_CACHE_INPUT_HASH_MASK; +} #endif diff --git a/net/core/dst_cache.c b/net/core/dst_cache.c index 0ccfd5fa5cb9..245f5546a7ff 100644 --- a/net/core/dst_cache.c +++ b/net/core/dst_cache.c @@ -13,6 +13,7 @@ #include #endif #include +#include struct dst_cache_pcpu { unsigned long refresh_ts; @@ -21,9 +22,12 @@ struct dst_cache_pcpu { union { struct in_addr in_saddr; struct in6_addr in6_saddr; + u64 key; }; }; +unsigned int dst_cache_net_id __read_mostly; + static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache, struct dst_entry *dst, u32 cookie) { @@ -181,3 +185,131 @@ void dst_cache_reset_now(struct dst_cache *dst_cache) } } EXPORT_SYMBOL_GPL(dst_cache_reset_now); + +static void dst_cache_input_set(struct dst_cache_pcpu *idst, + struct dst_entry *dst, u64 key) +{ + dst_cache_per_cpu_dst_set(idst, dst, 0); + idst->key = key; + idst->refresh_ts = jiffies; +} + +static struct dst_entry *__dst_cache_input_get_noref(struct dst_cache_pcpu *idst) +{ + struct dst_entry *dst = idst->dst; + + if (unlikely(dst->obsolete && !dst->ops->check(dst, idst->cookie))) { + dst_cache_input_set(idst, NULL, INVALID_DST_CACHE_INPUT_KEY); + goto fail; + } + + idst->refresh_ts = jiffies; + return dst; + +fail: + return NULL; +} + +struct dst_entry *dst_cache_input_get_noref(struct dst_cache *dst_cache, + struct sk_buff *skb) +{ + struct dst_entry *out_dst = NULL; + struct dst_cache_pcpu *pcpu_cache; + struct dst_cache_pcpu *idst; + u32 hash; + u64 key; + + pcpu_cache = this_cpu_ptr(dst_cache->cache); + key = create_dst_cache_key_ip4(skb); + hash = hash_dst_cache_key(key); + idst_for_each_in_bucket(idst, pcpu_cache, hash) { + if (key == idst->key) { + out_dst = __dst_cache_input_get_noref(idst); + goto out; + } + } +out: + return out_dst; +} + +static void dst_cache_input_reset_now(struct dst_cache *dst_cache) +{ + struct dst_cache_pcpu *caches; + struct dst_cache_pcpu *idst; + struct dst_entry *dst; + int i; + + for_each_possible_cpu(i) { + caches = per_cpu_ptr(dst_cache->cache, i); + idst_for_each_in_cache(idst, caches) { + idst->key = INVALID_DST_CACHE_INPUT_KEY; + dst = idst->dst; + if (dst) + dst_release(dst); + } + } +} + +static int __net_init dst_cache_input_net_init(struct net *net) +{ + struct dst_cache *dst_cache = net_generic(net, dst_cache_net_id); + + dst_cache->cache = (struct dst_cache_pcpu __percpu *)alloc_percpu_gfp(struct dst_cache_pcpu[DST_CACHE_INPUT_SIZE], + GFP_KERNEL | __GFP_ZERO); + if (!dst_cache->cache) + return -ENOMEM; + + dst_cache_input_reset_now(dst_cache); + return 0; +} + +static void __net_exit dst_cache_input_net_exit(struct net *net) +{ + struct dst_cache *dst_cache = net_generic(net, dst_cache_net_id); + + dst_cache_input_reset_now(dst_cache); + free_percpu(dst_cache->cache); + dst_cache->cache = NULL; +} + +static bool idst_empty(struct dst_cache_pcpu *idst) +{ + return idst->key == INVALID_DST_CACHE_INPUT_KEY; +} + +void dst_cache_input_add(struct dst_cache *dst_cache, const struct sk_buff *skb) +{ + struct dst_cache_pcpu *entry = NULL; + struct dst_cache_pcpu *pcpu_cache; + struct dst_cache_pcpu *idst; + u32 hash; + u64 key; + + pcpu_cache = this_cpu_ptr(dst_cache->cache); + key = create_dst_cache_key_ip4(skb); + hash = hash_dst_cache_key(key); + idst_for_each_in_bucket(idst, pcpu_cache, hash) { + if (idst_empty(idst)) { + entry = idst; + goto add_to_cache; + } + if (!entry || time_before(idst->refresh_ts, entry->refresh_ts)) + entry = idst; + } + +add_to_cache: + dst_cache_input_set(entry, skb_dst(skb), key); +} + +static struct pernet_operations dst_cache_input_ops __net_initdata = { + .init = dst_cache_input_net_init, + .exit = dst_cache_input_net_exit, + .id = &dst_cache_net_id, + .size = sizeof(struct dst_cache), +}; + +int __init dst_cache_input_init(void) +{ + return register_pernet_subsys(&dst_cache_input_ops); +} +subsys_initcall(dst_cache_input_init); -- 2.34.1