From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:52319) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QlfmO-0000US-OV for qemu-devel@nongnu.org; Tue, 26 Jul 2011 07:26:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QlfmN-0008Ey-Vv for qemu-devel@nongnu.org; Tue, 26 Jul 2011 07:26:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48655) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QlfmN-0008Ed-OZ for qemu-devel@nongnu.org; Tue, 26 Jul 2011 07:26:27 -0400 From: Avi Kivity Date: Tue, 26 Jul 2011 14:26:03 +0300 Message-Id: <1311679582-11211-5-git-send-email-avi@redhat.com> In-Reply-To: <1311679582-11211-1-git-send-email-avi@redhat.com> References: <1311679582-11211-1-git-send-email-avi@redhat.com> Subject: [Qemu-devel] [PATCH v2 04/23] memory: merge adjacent segments of a single memory region List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori , 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 | 29 +++++++++++++++++++++++++++++ 1 files changed, 29 insertions(+), 0 deletions(-) diff --git a/memory.c b/memory.c index d858b47..121f9e1 100644 --- a/memory.c +++ b/memory.c @@ -122,6 +122,34 @@ static void flatview_destroy(FlatView *view) qemu_free(view->ranges); } +static bool can_merge(FlatRange *r1, FlatRange *r2) +{ + return 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; +} + +/* Attempt to simplify a view by merging ajacent ranges */ +static void flatview_simplify(FlatView *view) +{ + unsigned i, j; + + i = 0; + while (i < view->nr) { + j = i + 1; + while (j < view->nr + && can_merge(&view->ranges[j-1], &view->ranges[j])) { + view->ranges[i].addr.size += view->ranges[j].addr.size; + ++j; + } + ++i; + memmove(&view->ranges[i], &view->ranges[j], + (view->nr - j) * sizeof(view->ranges[j])); + view->nr -= j - i; + } +} + /* Render a memory region into the global view. Ranges in @view obscure * ranges in @mr. */ @@ -209,6 +237,7 @@ 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