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 5E0CEC4332F for ; Fri, 10 Nov 2023 17:43:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345944AbjKJRni (ORCPT ); Fri, 10 Nov 2023 12:43:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233925AbjKJRmj (ORCPT ); Fri, 10 Nov 2023 12:42:39 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8BEB446C9 for ; Fri, 10 Nov 2023 09:25:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1699637147; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=oM2mXDeA3Wf82Oz0QJWRHggvqKfyd3kHZcBXsRiuhQg=; b=TfSR4+U+vukNTA5byyoGWj5YMw9cfbkyslFv8GsKU52eeqSpmDNbaczFHkX2ffcbftD52s FyAWVcuF5WiMuZNjQhA6hgtLPw2dLXjYZmWHmrhEfu8A5QoBx62mufQZn/PRb+SSSOHR2g GAtu8wKPX2X/iBpaa52aYZXlhpU9bYM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-427-pjuAe0pPOSO1_br2upm_yw-1; Fri, 10 Nov 2023 12:25:44 -0500 X-MC-Unique: pjuAe0pPOSO1_br2upm_yw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 00A4185A5BD; Fri, 10 Nov 2023 17:25:44 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.13]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3BB18502A; Fri, 10 Nov 2023 17:25:43 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <6fadc6aa-4078-4f12-a4c7-235267d6e0b1@auristor.com> <20231109154004.3317227-1-dhowells@redhat.com> <20231109154004.3317227-2-dhowells@redhat.com> <3327953.1699567608@warthog.procyon.org.uk> To: Jeffrey E Altman Cc: dhowells@redhat.com, Marc Dionne , linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 01/41] rxrpc: Fix RTT determination to use PING ACKs as a source MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3399755.1699637142.1@warthog.procyon.org.uk> Date: Fri, 10 Nov 2023 17:25:42 +0000 Message-ID: <3399756.1699637142@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jeffrey E Altman wrote: > > I do ignore ack.serial == 0 for this purpose. > > Zero has the special meaning - this ACK is not explicitly in response to a > received packet. > > However, as mentioned, the serial number counter wraps frequently and most > RxRPC implementations > do not transition from serial 0xffffffff -> 0x00000001 when wrapping. I don't skip zero serial numbers either. I'm not sure whether it would be better to do so. > Otherwise, acked_serial = 0x01 will be considered smaller than orig_serial = > 0xfffffffe and the slot will not be marked available. As you mentioned in your follow up email, after() deals with that by casting to signed, subtracting and then examining the result. David