From nobody Mon Nov 3 20:20:23 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1505984427305309.7339726427098; Thu, 21 Sep 2017 02:00:27 -0700 (PDT) Received: from localhost ([::1]:52455 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1duxLM-0003yR-BY for importer@patchew.org; Thu, 21 Sep 2017 05:00:24 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48505) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1duxCq-00056N-0U for qemu-devel@nongnu.org; Thu, 21 Sep 2017 04:51:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1duxCo-0001J9-T9 for qemu-devel@nongnu.org; Thu, 21 Sep 2017 04:51:36 -0400 Received: from ozlabs.ru ([107.173.13.209]:54112) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1duxCo-0001CA-KH for qemu-devel@nongnu.org; Thu, 21 Sep 2017 04:51:34 -0400 Received: from vpl1.ozlabs.ibm.com (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id 7D6793A60056; Thu, 21 Sep 2017 04:52:50 -0400 (EDT) From: Alexey Kardashevskiy To: qemu-devel@nongnu.org Date: Thu, 21 Sep 2017 18:51:04 +1000 Message-Id: <20170921085110.25598-13-aik@ozlabs.ru> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170921085110.25598-1-aik@ozlabs.ru> References: <20170921085110.25598-1-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 v5 12/18] memory: Share FlatView's and dispatch trees between address spaces X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This allows sharing flat views between address spaces (AS) when the same root memory region is used when creating a new address space. This is done by walking through all ASes and caching one FlatView per a physical root MR (i.e. not aliased). This removes search for duplicates from address_space_init_shareable() as FlatViews are shared elsewhere and keeping as::ref_count correct seems an unnecessary and useless complication. This should cause no change and memory use or boot time yet. Signed-off-by: Alexey Kardashevskiy --- Changes: v5: * s/flatview_set_to_address_space/address_space_set_flatview/g * generate_memory_topology() does g_hash_table_replace() as well v4: * used g_hash_table_new_full() instead of g_hash_table_new() + g_hash_table_foreach_remove() * cached last hash table of FV globally v3: * got rid of global and per-AS lists of FlatView objects --- memory.c | 56 +++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 45 insertions(+), 11 deletions(-) diff --git a/memory.c b/memory.c index 9868d0f57c..56b3dd47ab 100644 --- a/memory.c +++ b/memory.c @@ -47,6 +47,8 @@ static QTAILQ_HEAD(memory_listeners, MemoryListener) memo= ry_listeners static QTAILQ_HEAD(, AddressSpace) address_spaces =3D QTAILQ_HEAD_INITIALIZER(address_spaces); =20 +static GHashTable *flat_views; + typedef struct AddrRange AddrRange; =20 /* @@ -760,6 +762,7 @@ static FlatView *generate_memory_topology(MemoryRegion = *mr) flatview_add_to_dispatch(view, &mrs); } address_space_dispatch_compact(view->dispatch); + g_hash_table_replace(flat_views, mr, view); =20 return view; } @@ -925,11 +928,47 @@ static void address_space_update_topology_pass(Addres= sSpace *as, } } =20 -static void address_space_update_topology(AddressSpace *as) +static void flatviews_init(void) +{ + if (flat_views) { + return; + } + + flat_views =3D g_hash_table_new_full(g_direct_hash, g_direct_equal, NU= LL, + (GDestroyNotify) flatview_unref); +} + +static void flatviews_reset(void) +{ + AddressSpace *as; + + if (flat_views) { + g_hash_table_unref(flat_views); + flat_views =3D NULL; + } + flatviews_init(); + + /* Render unique FVs */ + QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) { + MemoryRegion *physmr =3D memory_region_get_flatview_root(as->root); + + if (g_hash_table_lookup(flat_views, physmr)) { + continue; + } + + generate_memory_topology(physmr); + } +} + +static void address_space_set_flatview(AddressSpace *as) { FlatView *old_view =3D address_space_get_flatview(as); - MemoryRegion *physmr =3D memory_region_get_flatview_root(old_view->roo= t); - FlatView *new_view =3D generate_memory_topology(physmr); + MemoryRegion *physmr =3D memory_region_get_flatview_root(as->root); + FlatView *new_view =3D g_hash_table_lookup(flat_views, physmr); + + assert(new_view); + + flatview_ref(new_view); =20 if (!QTAILQ_EMPTY(&as->listeners)) { address_space_update_topology_pass(as, old_view, new_view, false); @@ -965,10 +1004,12 @@ void memory_region_transaction_commit(void) --memory_region_transaction_depth; if (!memory_region_transaction_depth) { if (memory_region_update_pending) { + flatviews_reset(); + MEMORY_LISTENER_CALL_GLOBAL(begin, Forward); =20 QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) { - address_space_update_topology(as); + address_space_set_flatview(as); address_space_update_ioeventfds(as); } memory_region_update_pending =3D false; @@ -2691,13 +2732,6 @@ AddressSpace *address_space_init_shareable(MemoryReg= ion *root, const char *name) { AddressSpace *as; =20 - QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) { - if (root =3D=3D as->root && as->malloced) { - as->ref_count++; - return as; - } - } - as =3D g_malloc0(sizeof *as); address_space_init(as, root, name); as->malloced =3D true; --=20 2.11.0