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 63246C7618B for ; Mon, 29 Jul 2019 07:51:46 +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 38FEC206E0 for ; Mon, 29 Jul 2019 07:51:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 38FEC206E0 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]:50264 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hs0Rd-0000X8-Ib for qemu-devel@archiver.kernel.org; Mon, 29 Jul 2019 03:51:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40276) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hs0Qv-0007jP-RC for qemu-devel@nongnu.org; Mon, 29 Jul 2019 03:51:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hs0Qu-0008Of-Ra for qemu-devel@nongnu.org; Mon, 29 Jul 2019 03:51:01 -0400 Received: from mga04.intel.com ([192.55.52.120]:18589) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hs0Qu-0008Ma-IH for qemu-devel@nongnu.org; Mon, 29 Jul 2019 03:51:00 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Jul 2019 00:50:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,321,1559545200"; d="scan'208";a="162099284" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga007.jf.intel.com with ESMTP; 29 Jul 2019 00:50:57 -0700 Date: Mon, 29 Jul 2019 15:50:35 +0800 From: Wei Yang To: David Hildenbrand Message-ID: <20190729075035.GB2255@richard> References: <20190728131304.1282-1-richardw.yang@linux.intel.com> <20190728131304.1282-3-richardw.yang@linux.intel.com> <07a5431d-1928-d1ab-a0a2-7be21b411742@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <07a5431d-1928-d1ab-a0a2-7be21b411742@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: 192.55.52.120 Subject: Re: [Qemu-devel] [PATCH 2/3] memory-device: break the loop if no hint is provided 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 09:45:24AM +0200, David Hildenbrand wrote: >On 28.07.19 15:13, Wei Yang wrote: >> When there is no hint, the first un-overlapped range is the proper one. >> Just break the loop instead of iterate the whole list. >> >> Signed-off-by: Wei Yang >> --- >> hw/mem/memory-device.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c >> index df3261b32a..413b514586 100644 >> --- a/hw/mem/memory-device.c >> +++ b/hw/mem/memory-device.c >> @@ -180,6 +180,8 @@ static uint64_t memory_device_get_free_addr(MachineState *ms, >> range_make_empty(&new); >> break; >> } >> + } else if (!hint) { >> + break; >> } >> } >> >> > >I think > >a) This is fine. I was not able to construct a counter-example where >this would not work. Whenever we modify the range, we check against the >next one in the sorted list. If there is no overlap, it fits. And, it >won't overlap with any other range (and therefore never be changed again) > >b) This should therefore not change the assignment order / break migration. > >Maybe mention that this will not change the assigned addresses compared >to old code in all scenarios. > Thanks, let me add this in change log. >Reviewed-by: David Hildenbrand > >-- > >Thanks, > >David / dhildenb -- Wei Yang Help you, Help me