From mboxrd@z Thu Jan 1 00:00:00 1970 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 From: Avi Kivity 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> Subject: [Qemu-devel] [RFC v2 03/20] memory: merge adjacent segments of a single memory region List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kvm@vger.kernel.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; } -- 1.7.5.3