From patchwork Wed Mar 30 08:20:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artem Savkov X-Patchwork-Id: 12795569 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 5213AC433F5 for ; Wed, 30 Mar 2022 08:21:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244278AbiC3IXB (ORCPT ); Wed, 30 Mar 2022 04:23:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244264AbiC3IW6 (ORCPT ); Wed, 30 Mar 2022 04:22:58 -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 047BB30F79 for ; Wed, 30 Mar 2022 01:21:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1648628471; 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=EobXktrW0+gkWzx8tiaOBo7h9Vugaosu9pBImxeEgKAHo3ifFWXYJs0b/mhdt8E19tT/WG dASw+oRJDkOnT/i2Ij0fuI94mLraD55uQLHnqU20WDIOn1nR0g2l2x3nqrFFYD6Ne7N/UL j/h1n+u/Zw2UpvhDyciHjmu+ElM7Oak= 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-474-qz63oN9hMCCk3vbMmhF4qQ-1; Wed, 30 Mar 2022 04:21:07 -0400 X-MC-Unique: qz63oN9hMCCk3vbMmhF4qQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 4CE40100BAB1; Wed, 30 Mar 2022 08:20:56 +0000 (UTC) Received: from shodan.usersys.redhat.com (unknown [10.43.17.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BD8612166B3F; Wed, 30 Mar 2022 08:20:49 +0000 (UTC) Received: by shodan.usersys.redhat.com (Postfix, from userid 1000) id B64E21C021C; Wed, 30 Mar 2022 10:20:46 +0200 (CEST) From: Artem Savkov To: netdev@vger.kernel.org, Thomas Gleixner , asavkov@redhat.com, Josh Poimboeuf Cc: davem@davemloft.net, yoshfuji@linux-ipv6.org, Anna-Maria Gleixner , dsahern@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] net: make tcp keepalive timer upper bound Date: Wed, 30 Mar 2022 10:20:46 +0200 Message-Id: <20220330082046.3512424-3-asavkov@redhat.com> In-Reply-To: <20220330082046.3512424-1-asavkov@redhat.com> References: <87zglcfmcv.ffs@tglx> <20220330082046.3512424-1-asavkov@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 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 Reported-by: kernel test robot --- 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);