From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 305AAC41535 for ; Thu, 22 Dec 2022 21:47:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235374AbiLVVrL (ORCPT ); Thu, 22 Dec 2022 16:47:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229704AbiLVVrJ (ORCPT ); Thu, 22 Dec 2022 16:47:09 -0500 Received: from mail-yb1-xb2f.google.com (mail-yb1-xb2f.google.com [IPv6:2607:f8b0:4864:20::b2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4C6E13D4E for ; Thu, 22 Dec 2022 13:47:08 -0800 (PST) Received: by mail-yb1-xb2f.google.com with SMTP id o127so3473109yba.5 for ; Thu, 22 Dec 2022 13:47:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=IHKW/UYh8AR6b99fJnCGGe38aX1RLSFdq4cd+6sQxnU=; b=R5dVmWX9uznVV/vbtqSxZZhyCpGi2J4HUY07dFhPBBo7QZC64Vm582eE/BzVtryodX HHxK9TSnovmCQghXHIH9ASBjI4c+d9HTN1UljDEu+/2ZwFJH/TeFp5OUbVNRqE1xP6uk kb3w8T9255G1reCgW4ruvDZmKEcYVvJj/1UlLIexsI6J6R7AH08r/43/ITjwnvuwLnF8 ZQRZs6g6xN0nszBQkcqPZCMk75Up0hsPxiqegme2wKe+Z8wBpQ0+IBtKZ+xPactqDHQe s/1Xljev1reQTBJOjDnIeb1RkoT/i6fxxndix9emWt06IC1Kh4jL1ETlw6iEJ/IcC91T naiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=IHKW/UYh8AR6b99fJnCGGe38aX1RLSFdq4cd+6sQxnU=; b=pJOQH5AZOKE5V4kp/9WH2zBp9/9FRspmAT0C/JaiTKUUuVryMDe9LYMqlUpuShpiMj /FTGfqU9WUq2GK0OCqIFiXuy9SquDXJVvYPnY+VnP8KkUcYQriJEFVgmPJhOHgxkKFwS 8SckjIYDvnrWa0V0F6tNK4Nx7rN00qxzsRdOdvTZQ8m/Yw7jCFLWF/bNoY5margU1n8o nLE+Ej86W/cff9zHMRpjooIXT9UoXQLbfp8QdrP6X7ln8C+cw+4/BwcyX7TklL+MDlNu UgYu7R278g19UL0beI1z1oJfD2KZFD+ysMggFIL2txbcPIei+3J5NiGk2bP0iua0Y4SE a2Rg== X-Gm-Message-State: AFqh2krgl9WOs3g9n3PaLFEEF2lLxmQOyA+mcuIrYQ0YxtcTERpgu8N/ 1dfUDaRxjv8smLOh3ugvKs6Wi+3l5ETaFjEPHxo= X-Google-Smtp-Source: AMrXdXuM0vFKOz9E33an+lP9VwepId+FMAYPRCcptYUgKY/3yLZoEbWj+3bwSXPKIG9G90R5pgA/LhC1gc9KGg6jFFs= X-Received: by 2002:a25:f03:0:b0:718:7dec:7137 with SMTP id 3-20020a250f03000000b007187dec7137mr472898ybp.129.1671745628110; Thu, 22 Dec 2022 13:47:08 -0800 (PST) MIME-Version: 1.0 References: <20221221151258.25748-1-kuniyu@amazon.com> <20221221151258.25748-2-kuniyu@amazon.com> <95544fb4dd85d5acaca883bb8bae0e43821758bd.camel@redhat.com> In-Reply-To: <95544fb4dd85d5acaca883bb8bae0e43821758bd.camel@redhat.com> From: Joanne Koong Date: Thu, 22 Dec 2022 13:46:57 -0800 Message-ID: Subject: Re: [PATCH RFC net 1/2] tcp: Add TIME_WAIT sockets in bhash2. To: Paolo Abeni Cc: Kuniyuki Iwashima , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Jiri Slaby , Kuniyuki Iwashima , netdev@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Dec 22, 2022 at 7:06 AM Paolo Abeni wrote: > > On Thu, 2022-12-22 at 00:12 +0900, Kuniyuki Iwashima wrote: > > Jiri Slaby reported regression of bind() with a simple repro. [0] > > > > The repro creates a TIME_WAIT socket and tries to bind() a new socket > > with the same local address and port. Before commit 28044fc1d495 ("net: > > Add a bhash2 table hashed by port and address"), the bind() failed with > > -EADDRINUSE, but now it succeeds. > > > > The cited commit should have put TIME_WAIT sockets into bhash2; otherwise, > > inet_bhash2_conflict() misses TIME_WAIT sockets when validating bind() > > requests if the address is not a wildcard one. (resending my reply because it wasn't in plaintext mode) Thanks for adding this! I hadn't realized TIME_WAIT sockets also are considered when checking against inet bind conflicts. > > How does keeping the timewait sockets inside bhash2 affect the bind > loopup performance? I fear that could defeat completely the goal of > 28044fc1d495, on quite busy server we could have quite a bit of tw with > the same address/port. If so, we could even consider reverting > 28044fc1d495. > Can you clarify what you mean by bind loopup? > > [0]: https://lore.kernel.org/netdev/6b971a4e-c7d8-411e-1f92-fda29b5b2fb9@kernel.org/ > > > > Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address") > > Reported-by: Jiri Slaby > > Signed-off-by: Kuniyuki Iwashima > > --- > > include/net/inet_timewait_sock.h | 2 ++ > > include/net/sock.h | 5 +++-- > > net/ipv4/inet_hashtables.c | 5 +++-- > > net/ipv4/inet_timewait_sock.c | 31 +++++++++++++++++++++++++++++-- > > 4 files changed, 37 insertions(+), 6 deletions(-) > > > > diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h > > index 5b47545f22d3..c46ed239ad9a 100644 > > --- a/include/net/inet_timewait_sock.h > > +++ b/include/net/inet_timewait_sock.h > > @@ -44,6 +44,7 @@ struct inet_timewait_sock { > > #define tw_bound_dev_if __tw_common.skc_bound_dev_if > > #define tw_node __tw_common.skc_nulls_node > > #define tw_bind_node __tw_common.skc_bind_node > > +#define tw_bind2_node __tw_common.skc_bind2_node > > #define tw_refcnt __tw_common.skc_refcnt > > #define tw_hash __tw_common.skc_hash > > #define tw_prot __tw_common.skc_prot > > @@ -73,6 +74,7 @@ struct inet_timewait_sock { > > u32 tw_priority; > > struct timer_list tw_timer; > > struct inet_bind_bucket *tw_tb; > > + struct inet_bind2_bucket *tw_tb2; > > }; > > #define tw_tclass tw_tos > > > > diff --git a/include/net/sock.h b/include/net/sock.h > > index dcd72e6285b2..aaec985c1b5b 100644 > > --- a/include/net/sock.h > > +++ b/include/net/sock.h > > @@ -156,6 +156,7 @@ typedef __u64 __bitwise __addrpair; > > * @skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number > > * [union with @skc_incoming_cpu] > > * @skc_refcnt: reference count > > + * @skc_bind2_node: bind node in the bhash2 table > > * > > * This is the minimal network layer representation of sockets, the header > > * for struct sock and struct inet_timewait_sock. > > @@ -241,6 +242,7 @@ struct sock_common { > > u32 skc_window_clamp; > > u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */ > > }; > > + struct hlist_node skc_bind2_node; > > I *think* it would be better adding a tw_bind2_node field to the > inet_timewait_sock struct, so that we leave unmodified the request > socket and we don't change the struct sock binary layout. That could > affect performances moving hot fields on different cachelines. > +1. The rest of this patch LGTM. > > Thanks, > > Paolo >