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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 132E9C433FF for ; Mon, 29 Jul 2019 08:32:21 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DDAF7206E0 for ; Mon, 29 Jul 2019 08:32:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDAF7206E0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50442 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hs14u-00024d-5O for qemu-devel@archiver.kernel.org; Mon, 29 Jul 2019 04:32:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47368) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hs13O-00014m-J8 for qemu-devel@nongnu.org; Mon, 29 Jul 2019 04:30:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hs13N-0001Ah-Jv for qemu-devel@nongnu.org; Mon, 29 Jul 2019 04:30:46 -0400 Received: from mga11.intel.com ([192.55.52.93]:57412) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hs13N-0001A3-AI for qemu-devel@nongnu.org; Mon, 29 Jul 2019 04:30:45 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Jul 2019 01:30:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,322,1559545200"; d="scan'208";a="182657268" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga002.jf.intel.com with ESMTP; 29 Jul 2019 01:30:41 -0700 Date: Mon, 29 Jul 2019 16:30:19 +0800 From: Wei Yang To: David Hildenbrand Message-ID: <20190729083019.GC2255@richard> References: <20190728131304.1282-1-richardw.yang@linux.intel.com> <20190728131304.1282-4-richardw.yang@linux.intel.com> <690fd825-3553-6dee-5ff4-2ad7652afe46@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <690fd825-3553-6dee-5ff4-2ad7652afe46@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.93 Subject: Re: [Qemu-devel] [PATCH 3/3] memory-device: break the loop if tmp exceed the hinted range X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Wei Yang Cc: imammedo@redhat.com, mst@redhat.com, Wei Yang , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Jul 29, 2019 at 09:49:37AM +0200, David Hildenbrand wrote: >On 28.07.19 15:13, Wei Yang wrote: >> The memory-device list built by memory_device_build_list is ordered by >> its address, this means if the tmp range exceed the hinted range, all >> the following range will not overlap with it. >> >> Signed-off-by: Wei Yang >> --- >> hw/mem/memory-device.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c >> index 413b514586..aea47ab3e8 100644 >> --- a/hw/mem/memory-device.c >> +++ b/hw/mem/memory-device.c >> @@ -180,7 +180,7 @@ static uint64_t memory_device_get_free_addr(MachineState *ms, >> range_make_empty(&new); >> break; >> } >> - } else if (!hint) { >> + } else if (!hint || range_lob(&tmp) > range_upb(&new)) { >> break; >> } >> } >> > >Lower bound is inclusive, upper bound is exclusive. Shouldn't this be > >range_lob(&tmp) >= range_upb(&new) > Per my understanding, a range with start = 0, size = 0x10000, is represented [0, 0xffff] So if I have another range [0xffff, 0x1ffff], they seems to overlap. The range [0x10000, 0x1ffff] doesn't overlap with [0, 0xffff]. My original comparison looks right. Do I miss some point? >Also, I wonder if patch #2 is now really needed? > Hmm... I think you are right. I am afraid without Patch #2, the condition check is not that intuitive. Would this bring some confusion for audience and maintenance? I am not sure the percentage of occurrence when hint is provided, while the generated code for check NULL is less than compare two values. >-- > >Thanks, > >David / dhildenb -- Wei Yang Help you, Help me