{"id":816314,"url":"http://patchwork.ozlabs.org/api/patches/816314/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170920114637.42004-14-aik@ozlabs.ru/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20170920114637.42004-14-aik@ozlabs.ru>","list_archive_url":null,"date":"2017-09-20T11:46:32","name":"[qemu,v4,13/18] memory: Do not allocate FlatView in address_space_init","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"c647e7ea2dfa2f4b8be2100bf3fdc2ee3dd6c061","submitter":{"id":7621,"url":"http://patchwork.ozlabs.org/api/people/7621/?format=json","name":"Alexey Kardashevskiy","email":"aik@ozlabs.ru"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170920114637.42004-14-aik@ozlabs.ru/mbox/","series":[{"id":4138,"url":"http://patchwork.ozlabs.org/api/series/4138/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=4138","date":"2017-09-20T11:46:20","name":"memory: Reduce memory use","version":4,"mbox":"http://patchwork.ozlabs.org/series/4138/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/816314/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/816314/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":"ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=)","Received":["from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xy3jM0Mwnz9t2Q\n\tfor ;\n\tThu, 21 Sep 2017 01:35:33 +1000 (AEST)","from localhost ([::1]:48920 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1duh2B-0003Lp-QJ\n\tfor incoming@patchwork.ozlabs.org; Wed, 20 Sep 2017 11:35:31 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:56355)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1dufmG-0003O3-M2\n\tfor qemu-devel@nongnu.org; Wed, 20 Sep 2017 10:15:02 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from ) id 1dufmE-000584-2Z\n\tfor qemu-devel@nongnu.org; Wed, 20 Sep 2017 10:15:00 -0400","from ozlabs.ru ([107.173.13.209]:59750)\n\tby eggs.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1dufmD-00057Q-Ks\n\tfor qemu-devel@nongnu.org; Wed, 20 Sep 2017 10:14:57 -0400","from vpl1.ozlabs.ibm.com (localhost [IPv6:::1])\n\tby ozlabs.ru (Postfix) with ESMTP id 558F63A6005C;\n\tWed, 20 Sep 2017 07:48:12 -0400 (EDT)"],"From":"Alexey Kardashevskiy ","To":"qemu-devel@nongnu.org","Date":"Wed, 20 Sep 2017 21:46:32 +1000","Message-Id":"<20170920114637.42004-14-aik@ozlabs.ru>","X-Mailer":"git-send-email 2.11.0","In-Reply-To":"<20170920114637.42004-1-aik@ozlabs.ru>","References":"<20170920114637.42004-1-aik@ozlabs.ru>","X-detected-operating-system":"by eggs.gnu.org: GNU/Linux 3.x [fuzzy]","X-Received-From":"107.173.13.209","Subject":"[Qemu-devel] [PATCH qemu v4 13/18] memory: Do not allocate FlatView\n\tin address_space_init","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"Alexey Kardashevskiy , Paolo Bonzini ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"},"content":"This creates a new AS object without any FlatView as\nmemory_region_transaction_commit() may want to reuse the empty FV.\n\nSigned-off-by: Alexey Kardashevskiy \n---\n\nI do not really want to add view!=NULL into\nflatview_ref()/flatview_unref() as this is quite special case when\nview==NULL.\n---\n memory.c | 29 +++++++++++++++++++++++------\n 1 file changed, 23 insertions(+), 6 deletions(-)","diff":"diff --git a/memory.c b/memory.c\nindex 1083fe9130..aa8a49539d 100644\n--- a/memory.c\n+++ b/memory.c\n@@ -963,22 +963,37 @@ static void flatviews_reset(void)\n \n static void flatview_set_to_address_space(AddressSpace *as)\n {\n- FlatView *old_view = address_space_get_flatview(as);\n+ FlatView *old_view = address_space_to_flatview(as);\n MemoryRegion *physmr = memory_region_get_flatview_root(as->root);\n FlatView *new_view = g_hash_table_lookup(flat_views, physmr);\n \n assert(new_view);\n \n+ if (old_view == new_view) {\n+ return;\n+ }\n+\n+ if (old_view) {\n+ flatview_ref(old_view);\n+ }\n+\n flatview_ref(new_view);\n \n if (!QTAILQ_EMPTY(&as->listeners)) {\n- address_space_update_topology_pass(as, old_view, new_view, false);\n- address_space_update_topology_pass(as, old_view, new_view, true);\n+ FlatView tmpview = { 0 }, *old_view2 = old_view;\n+\n+ if (!old_view2) {\n+ old_view2 = &tmpview;\n+ }\n+ address_space_update_topology_pass(as, old_view2, new_view, false);\n+ address_space_update_topology_pass(as, old_view2, new_view, true);\n }\n \n /* Writes are protected by the BQL. */\n atomic_rcu_set(&as->current_map, new_view);\n- flatview_unref(old_view);\n+ if (old_view) {\n+ flatview_unref(old_view);\n+ }\n \n /* Note that all the old MemoryRegions are still alive up to this\n * point. This relieves most MemoryListeners from the need to\n@@ -986,7 +1001,9 @@ static void flatview_set_to_address_space(AddressSpace *as)\n * outside the iothread mutex, in which case precise reference\n * counting is necessary.\n */\n- flatview_unref(old_view);\n+ if (old_view) {\n+ flatview_unref(old_view);\n+ }\n }\n \n void memory_region_transaction_begin(void)\n@@ -2704,7 +2721,7 @@ void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)\n as->ref_count = 1;\n as->root = root;\n as->malloced = false;\n- as->current_map = flatview_new(root);\n+ as->current_map = NULL;\n as->ioeventfd_nb = 0;\n as->ioeventfds = NULL;\n QTAILQ_INIT(&as->listeners);\n","prefixes":["qemu","v4","13/18"]}