From patchwork Mon Jun 27 13:21:50 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avi Kivity X-Patchwork-Id: 102176 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 47351B6F90 for ; Mon, 27 Jun 2011 23:59:53 +1000 (EST) Received: from localhost ([::1]:40315 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QbCLu-0006Mw-0D for incoming@patchwork.ozlabs.org; Mon, 27 Jun 2011 09:59:50 -0400 Received: from eggs.gnu.org ([140.186.70.92]:48754) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QbBlg-0005jH-HR for qemu-devel@nongnu.org; Mon, 27 Jun 2011 09:22:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QbBlX-0002Fe-77 for qemu-devel@nongnu.org; Mon, 27 Jun 2011 09:22:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50565) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QbBlV-0002DM-7y for qemu-devel@nongnu.org; Mon, 27 Jun 2011 09:22:13 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p5RDMAF7009362 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 27 Jun 2011 09:22:10 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p5RDMAqR018273; Mon, 27 Jun 2011 09:22:10 -0400 Received: from s01.tlv.redhat.com (s01.tlv.redhat.com [10.35.255.8]) by cleopatra.tlv.redhat.com (Postfix) with ESMTP id BE8D0B063A; Mon, 27 Jun 2011 16:22:09 +0300 (IDT) From: Avi Kivity To: qemu-devel@nongnu.org Date: Mon, 27 Jun 2011 16:21:50 +0300 Message-Id: <1309180927-19003-4-git-send-email-avi@redhat.com> In-Reply-To: <1309180927-19003-1-git-send-email-avi@redhat.com> References: <1309180927-19003-1-git-send-email-avi@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 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] [RFC v2 03/20] 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 d962fff..f136714 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; }