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GET /api/patches/816314/?format=api
HTTP 200 OK
Allow: GET, PUT, PATCH, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "id": 816314,
    "url": "http://patchwork.ozlabs.org/api/patches/816314/?format=api",
    "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=api",
        "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=api",
        "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=api",
            "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": "<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>",
        "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=<UNKNOWN>)",
        "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 <incoming@patchwork.ozlabs.org>;\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<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>)\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 <aik@ozlabs.ru>) 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 <aik@ozlabs.ru>) 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 <aik@ozlabs.ru>) 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 <aik@ozlabs.ru>",
        "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": "<qemu-devel.nongnu.org>",
        "List-Unsubscribe": "<https://lists.nongnu.org/mailman/options/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>",
        "List-Archive": "<http://lists.nongnu.org/archive/html/qemu-devel/>",
        "List-Post": "<mailto:qemu-devel@nongnu.org>",
        "List-Help": "<mailto:qemu-devel-request@nongnu.org?subject=help>",
        "List-Subscribe": "<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=subscribe>",
        "Cc": "Alexey Kardashevskiy <aik@ozlabs.ru>, Paolo Bonzini <pbonzini@redhat.com>",
        "Errors-To": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org",
        "Sender": "\"Qemu-devel\"\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>"
    },
    "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 <aik@ozlabs.ru>\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"
    ]
}