From patchwork Mon Jul 25 14:02:44 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avi Kivity X-Patchwork-Id: 106706 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id A4331B6FAF for ; Tue, 26 Jul 2011 01:28:37 +1000 (EST) Received: from localhost ([::1]:53174 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QlLle-0006ye-Jc for incoming@patchwork.ozlabs.org; Mon, 25 Jul 2011 10:04:22 -0400 Received: from eggs.gnu.org ([140.186.70.92]:47314) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QlLkb-0003ql-D9 for qemu-devel@nongnu.org; Mon, 25 Jul 2011 10:03:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QlLkT-00051P-5A for qemu-devel@nongnu.org; Mon, 25 Jul 2011 10:03:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:63173) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QlLkS-00050s-Q2 for qemu-devel@nongnu.org; Mon, 25 Jul 2011 10:03:09 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p6PE37mA021751 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 25 Jul 2011 10:03:07 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p6PE37DO024448; Mon, 25 Jul 2011 10:03:07 -0400 Received: from s01.tlv.redhat.com (s01.tlv.redhat.com [10.35.255.8]) by cleopatra.tlv.redhat.com (Postfix) with ESMTP id BF59D250B39; Mon, 25 Jul 2011 17:03:06 +0300 (IDT) From: Avi Kivity To: qemu-devel@nongnu.org Date: Mon, 25 Jul 2011 17:02:44 +0300 Message-Id: <1311602584-23409-4-git-send-email-avi@redhat.com> In-Reply-To: <1311602584-23409-1-git-send-email-avi@redhat.com> References: <1311602584-23409-1-git-send-email-avi@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: kvm@vger.kernel.org Subject: [Qemu-devel] [PATCH 03/23] memory: merge adjacent segments of a single memory region X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Simple implementations of memory routers, for example the Cirrus VGA memory banks or the 440FX PAM registers can generate adjacent memory regions which are contiguous. Detect these and merge them; this saves kvm memory slots and shortens lookup times. Signed-off-by: Avi Kivity --- memory.c | 22 ++++++++++++++++++++++ 1 files changed, 22 insertions(+), 0 deletions(-) diff --git a/memory.c b/memory.c index a569666..339bea3 100644 --- a/memory.c +++ b/memory.c @@ -122,6 +122,27 @@ static void flatview_destroy(FlatView *view) qemu_free(view->ranges); } +/* Attempt to simplify a view by merging ajacent ranges */ +static void flatview_simplify(FlatView *view) +{ + unsigned i; + FlatRange *r1, *r2; + + for (i = 0; i + 1 < view->nr; ++i) { + r1 = &view->ranges[i]; + r2 = &view->ranges[i+1]; + if (addrrange_end(r1->addr) == r2->addr.start + && r1->mr == r2->mr + && r1->offset_in_region + r1->addr.size == r2->offset_in_region + && r1->dirty_log_mask == r2->dirty_log_mask) { + r1->addr.size += r2->addr.size; + memmove(r2, r2 + 1, (view->nr - (i + 2)) * sizeof(*r2)); + --view->nr; + --i; + } + } +} + /* Render a memory region into the global view. Ranges in @view obscure * ranges in @mr. */ @@ -209,6 +230,7 @@ static FlatView generate_memory_topology(MemoryRegion *mr) flatview_init(&view); render_memory_region(&view, mr, 0, addrrange_make(0, UINT64_MAX)); + flatview_simplify(&view); return view; }