From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [RFC v4 03/58] memory: merge adjacent segments of a single memory region Date: Sun, 17 Jul 2011 14:13:30 +0300 Message-ID: <1310901265-32051-4-git-send-email-avi@redhat.com> References: <1310901265-32051-1-git-send-email-avi@redhat.com> Cc: kvm@vger.kernel.org To: qemu-devel@nongnu.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:51831 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755665Ab1GQLOa (ORCPT ); Sun, 17 Jul 2011 07:14:30 -0400 In-Reply-To: <1310901265-32051-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: 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; } -- 1.7.5.3