From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [RFC v5 04/86] memory: merge adjacent segments of a single memory region Date: Wed, 20 Jul 2011 19:49:14 +0300 Message-ID: <1311180636-17012-5-git-send-email-avi@redhat.com> References: <1311180636-17012-1-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]:56820 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751368Ab1GTQum (ORCPT ); Wed, 20 Jul 2011 12:50:42 -0400 In-Reply-To: <1311180636-17012-1-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 From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:55240) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjZz8-00034B-Sb for qemu-devel@nongnu.org; Wed, 20 Jul 2011 12:51:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QjZys-0004tg-Dt for qemu-devel@nongnu.org; Wed, 20 Jul 2011 12:50:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35981) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjZyr-0004tI-Jk for qemu-devel@nongnu.org; Wed, 20 Jul 2011 12:50:42 -0400 From: Avi Kivity Date: Wed, 20 Jul 2011 19:49:14 +0300 Message-Id: <1311180636-17012-5-git-send-email-avi@redhat.com> In-Reply-To: <1311180636-17012-1-git-send-email-avi@redhat.com> References: <1311180636-17012-1-git-send-email-avi@redhat.com> Subject: [Qemu-devel] [RFC v5 04/86] 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 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