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: 920812 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p5RDdiKe019888 for ; Mon, 27 Jun 2011 13:39:47 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760027Ab1F0NYa (ORCPT ); Mon, 27 Jun 2011 09:24:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30716 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759965Ab1F0NWO (ORCPT ); Mon, 27 Jun 2011 09:22:14 -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 Cc: kvm@vger.kernel.org Subject: [RFC v2 03/20] memory: merge adjacent segments of a single memory region 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 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Mon, 27 Jun 2011 13:39:47 +0000 (UTC) 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; }