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GET /api/patches/814161/?format=api
HTTP 200 OK
Allow: GET, PUT, PATCH, HEAD, OPTIONS
Content-Type: application/json
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{
    "id": 814161,
    "url": "http://patchwork.ozlabs.org/api/patches/814161/?format=api",
    "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20170915084030.40988-6-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": "<20170915084030.40988-6-aik@ozlabs.ru>",
    "list_archive_url": null,
    "date": "2017-09-15T08:40:22",
    "name": "[qemu,v2,05/13] memory: Move AddressSpaceDispatch from AddressSpace to FlatView",
    "commit_ref": null,
    "pull_url": null,
    "state": "new",
    "archived": false,
    "hash": "c38d31f5d1bd6af791d7c2f90d5bcc7f9a2481fe",
    "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/20170915084030.40988-6-aik@ozlabs.ru/mbox/",
    "series": [
        {
            "id": 3250,
            "url": "http://patchwork.ozlabs.org/api/series/3250/?format=api",
            "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=3250",
            "date": "2017-09-15T08:40:21",
            "name": "memory: Reduce memory use",
            "version": 2,
            "mbox": "http://patchwork.ozlabs.org/series/3250/mbox/"
        }
    ],
    "comments": "http://patchwork.ozlabs.org/api/patches/814161/comments/",
    "check": "pending",
    "checks": "http://patchwork.ozlabs.org/api/patches/814161/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 3xtpzS3pJcz9sPr\n\tfor <incoming@patchwork.ozlabs.org>;\n\tFri, 15 Sep 2017 18:51:32 +1000 (AEST)",
            "from localhost ([::1]:52000 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 1dsmLS-000132-Ip\n\tfor incoming@patchwork.ozlabs.org; Fri, 15 Sep 2017 04:51:30 -0400",
            "from eggs.gnu.org ([2001:4830:134:3::10]:38450)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <aik@ozlabs.ru>) id 1dsmBV-0007LM-Ce\n\tfor qemu-devel@nongnu.org; Fri, 15 Sep 2017 04:41:14 -0400",
            "from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from <aik@ozlabs.ru>) id 1dsmBT-0002gt-Ok\n\tfor qemu-devel@nongnu.org; Fri, 15 Sep 2017 04:41:13 -0400",
            "from ozlabs.ru ([107.173.13.209]:45038)\n\tby eggs.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <aik@ozlabs.ru>) id 1dsmBT-0002gc-AX\n\tfor qemu-devel@nongnu.org; Fri, 15 Sep 2017 04:41:11 -0400",
            "from vpl1.ozlabs.ibm.com (localhost [IPv6:::1])\n\tby ozlabs.ru (Postfix) with ESMTP id 4F67F3A60057;\n\tFri, 15 Sep 2017 04:41:54 -0400 (EDT)"
        ],
        "From": "Alexey Kardashevskiy <aik@ozlabs.ru>",
        "To": "qemu-devel@nongnu.org",
        "Date": "Fri, 15 Sep 2017 18:40:22 +1000",
        "Message-Id": "<20170915084030.40988-6-aik@ozlabs.ru>",
        "X-Mailer": "git-send-email 2.11.0",
        "In-Reply-To": "<20170915084030.40988-1-aik@ozlabs.ru>",
        "References": "<20170915084030.40988-1-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 v2 05/13] memory: Move\n\tAddressSpaceDispatch from AddressSpace to FlatView",
        "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": "As we are going to share FlatView's between AddressSpace's,\nand AddressSpaceDispatch is a structure to perform quick lookup\nin FlatView, this moves ASD to FlatView.\n\nAfter previosly open coded ASD rendering, we can also remove\nas->next_dispatch as the new FlatView pointer is stored\non a stack and set to an AS atomically.\n\nflatview_destroy() is executed under RCU instead of\naddress_space_dispatch_free() now.\n\nThis makes mem_begin/mem_commit to work with ASD and mem_add with FV\nas later on mem_add will be taking FV as an argument anyway.\n\nSigned-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>\n---\n include/exec/memory-internal.h | 13 ++++++++-----\n include/exec/memory.h          |  2 --\n exec.c                         | 41 +++++++++++------------------------------\n memory.c                       | 31 ++++++++++++++++++++++++-------\n 4 files changed, 43 insertions(+), 44 deletions(-)",
    "diff": "diff --git a/include/exec/memory-internal.h b/include/exec/memory-internal.h\nindex 9abde2f11c..08b7e01047 100644\n--- a/include/exec/memory-internal.h\n+++ b/include/exec/memory-internal.h\n@@ -21,17 +21,20 @@\n \n #ifndef CONFIG_USER_ONLY\n typedef struct AddressSpaceDispatch AddressSpaceDispatch;\n-\n-void address_space_destroy_dispatch(AddressSpace *as);\n+typedef struct FlatView FlatView;\n \n extern const MemoryRegionOps unassigned_mem_ops;\n \n bool memory_region_access_valid(MemoryRegion *mr, hwaddr addr,\n                                 unsigned size, bool is_write);\n \n-void mem_add(AddressSpace *as, MemoryRegionSection *section);\n-void mem_begin(AddressSpace *as);\n-void mem_commit(AddressSpace *as);\n+void mem_add(AddressSpace *as, FlatView *fv, MemoryRegionSection *section);\n+AddressSpaceDispatch *mem_begin(AddressSpace *as);\n+void mem_commit(AddressSpaceDispatch *d);\n+\n+AddressSpaceDispatch *address_space_to_dispatch(AddressSpace *as);\n+AddressSpaceDispatch *flatview_to_dispatch(FlatView *fv);\n+void address_space_dispatch_free(AddressSpaceDispatch *d);\n \n #endif\n #endif\ndiff --git a/include/exec/memory.h b/include/exec/memory.h\nindex 9581f7a7db..2346f8b863 100644\n--- a/include/exec/memory.h\n+++ b/include/exec/memory.h\n@@ -316,8 +316,6 @@ struct AddressSpace {\n \n     int ioeventfd_nb;\n     struct MemoryRegionIoeventfd *ioeventfds;\n-    struct AddressSpaceDispatch *dispatch;\n-    struct AddressSpaceDispatch *next_dispatch;\n     QTAILQ_HEAD(memory_listeners_as, MemoryListener) listeners;\n     QTAILQ_ENTRY(AddressSpace) address_spaces_link;\n };\ndiff --git a/exec.c b/exec.c\nindex 3ed3718dea..6b0211bafc 100644\n--- a/exec.c\n+++ b/exec.c\n@@ -188,8 +188,6 @@ typedef struct PhysPageMap {\n } PhysPageMap;\n \n struct AddressSpaceDispatch {\n-    struct rcu_head rcu;\n-\n     MemoryRegionSection *mru_section;\n     /* This is a multi-level map on the physical address space.\n      * The bottom level has pointers to MemoryRegionSections.\n@@ -486,7 +484,7 @@ static MemoryRegionSection address_space_do_translate(AddressSpace *as,\n     IOMMUMemoryRegionClass *imrc;\n \n     for (;;) {\n-        AddressSpaceDispatch *d = atomic_rcu_read(&as->dispatch);\n+        AddressSpaceDispatch *d = address_space_to_dispatch(as);\n         section = address_space_translate_internal(d, addr, &addr, plen, is_mmio);\n \n         iommu_mr = memory_region_get_iommu(section->mr);\n@@ -1223,7 +1221,7 @@ hwaddr memory_region_section_get_iotlb(CPUState *cpu,\n     } else {\n         AddressSpaceDispatch *d;\n \n-        d = atomic_rcu_read(&section->address_space->dispatch);\n+        d = address_space_to_dispatch(section->address_space);\n         iotlb = section - d->map.sections;\n         iotlb += xlat;\n     }\n@@ -1348,9 +1346,9 @@ static void register_multipage(AddressSpaceDispatch *d,\n     phys_page_set(d, start_addr >> TARGET_PAGE_BITS, num_pages, section_index);\n }\n \n-void mem_add(AddressSpace *as, MemoryRegionSection *section)\n+void mem_add(AddressSpace *as, FlatView *fv, MemoryRegionSection *section)\n {\n-    AddressSpaceDispatch *d = as->next_dispatch;\n+    AddressSpaceDispatch *d = flatview_to_dispatch(fv);\n     MemoryRegionSection now = *section, remain = *section;\n     Int128 page_size = int128_make64(TARGET_PAGE_SIZE);\n \n@@ -2673,7 +2671,7 @@ static void io_mem_init(void)\n                           NULL, UINT64_MAX);\n }\n \n-void mem_begin(AddressSpace *as)\n+AddressSpaceDispatch *mem_begin(AddressSpace *as)\n {\n     AddressSpaceDispatch *d = g_new0(AddressSpaceDispatch, 1);\n     uint16_t n;\n@@ -2689,26 +2687,19 @@ void mem_begin(AddressSpace *as)\n \n     d->phys_map  = (PhysPageEntry) { .ptr = PHYS_MAP_NODE_NIL, .skip = 1 };\n     d->as = as;\n-    as->next_dispatch = d;\n+\n+    return d;\n }\n \n-static void address_space_dispatch_free(AddressSpaceDispatch *d)\n+void address_space_dispatch_free(AddressSpaceDispatch *d)\n {\n     phys_sections_free(&d->map);\n     g_free(d);\n }\n \n-void mem_commit(AddressSpace *as)\n+void mem_commit(AddressSpaceDispatch *d)\n {\n-    AddressSpaceDispatch *cur = as->dispatch;\n-    AddressSpaceDispatch *next = as->next_dispatch;\n-\n-    phys_page_compact_all(next, next->map.nodes_nb);\n-\n-    atomic_rcu_set(&as->dispatch, next);\n-    if (cur) {\n-        call_rcu(cur, address_space_dispatch_free, rcu);\n-    }\n+    phys_page_compact_all(d, d->map.nodes_nb);\n }\n \n static void tcg_commit(MemoryListener *listener)\n@@ -2724,21 +2715,11 @@ static void tcg_commit(MemoryListener *listener)\n      * We reload the dispatch pointer now because cpu_reloading_memory_map()\n      * may have split the RCU critical section.\n      */\n-    d = atomic_rcu_read(&cpuas->as->dispatch);\n+    d = address_space_to_dispatch(cpuas->as);\n     atomic_rcu_set(&cpuas->memory_dispatch, d);\n     tlb_flush(cpuas->cpu);\n }\n \n-void address_space_destroy_dispatch(AddressSpace *as)\n-{\n-    AddressSpaceDispatch *d = as->dispatch;\n-\n-    atomic_rcu_set(&as->dispatch, NULL);\n-    if (d) {\n-        call_rcu(d, address_space_dispatch_free, rcu);\n-    }\n-}\n-\n static void memory_map_init(void)\n {\n     system_memory = g_malloc(sizeof(*system_memory));\ndiff --git a/memory.c b/memory.c\nindex a8381a8bc2..1d93e4c836 100644\n--- a/memory.c\n+++ b/memory.c\n@@ -229,6 +229,7 @@ struct FlatView {\n     FlatRange *ranges;\n     unsigned nr;\n     unsigned nr_allocated;\n+    struct AddressSpaceDispatch *dispatch;\n };\n \n typedef struct AddressSpaceOps AddressSpaceOps;\n@@ -289,6 +290,9 @@ static void flatview_destroy(FlatView *view)\n {\n     int i;\n \n+    if (view->dispatch) {\n+        address_space_dispatch_free(view->dispatch);\n+    }\n     for (i = 0; i < view->nr; i++) {\n         memory_region_unref(view->ranges[i].mr);\n     }\n@@ -304,10 +308,25 @@ static void flatview_ref(FlatView *view)\n static void flatview_unref(FlatView *view)\n {\n     if (atomic_fetch_dec(&view->ref) == 1) {\n-        flatview_destroy(view);\n+        call_rcu(view, flatview_destroy, rcu);\n     }\n }\n \n+static FlatView *address_space_to_flatview(AddressSpace *as)\n+{\n+    return atomic_rcu_read(&as->current_map);\n+}\n+\n+AddressSpaceDispatch *flatview_to_dispatch(FlatView *fv)\n+{\n+    return fv->dispatch;\n+}\n+\n+AddressSpaceDispatch *address_space_to_dispatch(AddressSpace *as)\n+{\n+    return flatview_to_dispatch(address_space_to_flatview(as));\n+}\n+\n static bool can_merge(FlatRange *r1, FlatRange *r2)\n {\n     return int128_eq(addrrange_end(r1->addr), r2->addr.start)\n@@ -887,7 +906,7 @@ static void address_space_update_flatview(AddressSpace *as,\n     unsigned iold, inew;\n     FlatRange *frold, *frnew;\n \n-    mem_begin(as);\n+    new_view->dispatch = mem_begin(as);\n     /*\n      * FIXME: this is cut-n-paste from address_space_update_topology_pass,\n      * simplify it\n@@ -915,7 +934,7 @@ static void address_space_update_flatview(AddressSpace *as,\n             /* In both and unchanged (except logging may have changed) */\n             MemoryRegionSection mrs = section_from_flat_range(frnew, as);\n \n-            mem_add(as, &mrs);\n+            mem_add(as, new_view, &mrs);\n \n             ++iold;\n             ++inew;\n@@ -923,12 +942,12 @@ static void address_space_update_flatview(AddressSpace *as,\n             /* In new */\n             MemoryRegionSection mrs = section_from_flat_range(frnew, as);\n \n-            mem_add(as, &mrs);\n+            mem_add(as, new_view, &mrs);\n \n             ++inew;\n         }\n     }\n-    mem_commit(as);\n+    mem_commit(new_view->dispatch);\n }\n \n static void address_space_update_topology(AddressSpace *as)\n@@ -2672,7 +2691,6 @@ void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)\n     QTAILQ_INIT(&as->listeners);\n     QTAILQ_INSERT_TAIL(&address_spaces, as, address_spaces_link);\n     as->name = g_strdup(name ? name : \"anonymous\");\n-    as->dispatch = NULL;\n     memory_region_update_pending |= root->enabled;\n     memory_region_transaction_commit();\n }\n@@ -2681,7 +2699,6 @@ static void do_address_space_destroy(AddressSpace *as)\n {\n     bool do_free = as->malloced;\n \n-    address_space_destroy_dispatch(as);\n     assert(QTAILQ_EMPTY(&as->listeners));\n \n     flatview_unref(as->current_map);\n",
    "prefixes": [
        "qemu",
        "v2",
        "05/13"
    ]
}