From patchwork Thu Apr 7 07:52:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artem Savkov X-Patchwork-Id: 12804611 X-Patchwork-Delegate: kuba@kernel.org 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 A7163C433EF for ; Thu, 7 Apr 2022 07:52:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242328AbiDGHy4 (ORCPT ); Thu, 7 Apr 2022 03:54:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242296AbiDGHyy (ORCPT ); Thu, 7 Apr 2022 03:54:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F381E1C404B for ; Thu, 7 Apr 2022 00:52:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1649317974; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qQwtpv4LSJs4oYZkfG+yHqo4mCAyzu9Mqm5FcRavI60=; b=OQZ+GXUBZWUXvircGf9m0koalw3o9ZDYMWmfAkK7/km6mBhbRSTHpZJSfGPtZq+XbOo2vo 4RuWAFzzfW1xXahc17B5/gCOfeljtIsejqK3bfRaUM6DD2/I8eonqDBT77c/sIMVieUM0I SxZZ4RCobaO4rXA73OVqyHy8wGjvHCQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-180-rDqrMzroPZCOxoo4cQkGGw-1; Thu, 07 Apr 2022 03:52:49 -0400 X-MC-Unique: rDqrMzroPZCOxoo4cQkGGw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 08864802819; Thu, 7 Apr 2022 07:52:48 +0000 (UTC) Received: from shodan.usersys.redhat.com (unknown [10.43.17.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 25F4940D2962; Thu, 7 Apr 2022 07:52:45 +0000 (UTC) Received: by shodan.usersys.redhat.com (Postfix, from userid 1000) id E84AC1C00CD; Thu, 7 Apr 2022 09:52:43 +0200 (CEST) From: Artem Savkov To: Thomas Gleixner , Josh Poimboeuf , Anna-Maria Behnsen , netdev@vger.kernel.org Cc: davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, linux-kernel@vger.kernel.org, Artem Savkov Subject: [PATCH v4 2/2] net: make tcp keepalive timer upper bound Date: Thu, 7 Apr 2022 09:52:42 +0200 Message-Id: <20220407075242.118253-3-asavkov@redhat.com> In-Reply-To: <20220407075242.118253-1-asavkov@redhat.com> References: <871qyb35q4.ffs@tglx> <20220407075242.118253-1-asavkov@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Make sure TCP keepalive timer does not expire late. Switching to upper bound timers means it can fire off early but in case of keepalive tcp_keepalive_timer() handler checks elapsed time and resets the timer if it was triggered early. This results in timer "cascading" to a higher precision and being just a couple of milliseconds off it's original mark. Signed-off-by: Artem Savkov --- net/ipv4/inet_connection_sock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 1e5b53c2bb267..bb2dbfb6f5b50 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -589,7 +589,7 @@ EXPORT_SYMBOL(inet_csk_delete_keepalive_timer); void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len) { - sk_reset_timer(sk, &sk->sk_timer, jiffies + len); + sk_reset_timer(sk, &sk->sk_timer, jiffies + upper_bound_timeout(len)); } EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);