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[Qemu-stable] [PATCH 18/55] memory: Share FlatView's and dispatch trees
From: |
Michael Roth |
Subject: |
[Qemu-stable] [PATCH 18/55] memory: Share FlatView's and dispatch trees between address spaces |
Date: |
Wed, 6 Dec 2017 13:16:11 -0600 |
From: Alexey Kardashevskiy <address@hidden>
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 <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
(cherry picked from commit 967dc9b1194a9281124b2e1ce67b6c3359a2138f)
Signed-off-by: Michael Roth <address@hidden>
---
memory.c | 56 +++++++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 45 insertions(+), 11 deletions(-)
diff --git a/memory.c b/memory.c
index 1f58d29755..f0c864206a 100644
--- a/memory.c
+++ b/memory.c
@@ -47,6 +47,8 @@ static QTAILQ_HEAD(memory_listeners, MemoryListener)
memory_listeners
static QTAILQ_HEAD(, AddressSpace) address_spaces
= QTAILQ_HEAD_INITIALIZER(address_spaces);
+static GHashTable *flat_views;
+
typedef struct AddrRange AddrRange;
/*
@@ -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);
return view;
}
@@ -929,11 +932,47 @@ static void
address_space_update_topology_pass(AddressSpace *as,
}
}
-static void address_space_update_topology(AddressSpace *as)
+static void flatviews_init(void)
+{
+ if (flat_views) {
+ return;
+ }
+
+ flat_views = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL,
+ (GDestroyNotify) flatview_unref);
+}
+
+static void flatviews_reset(void)
+{
+ AddressSpace *as;
+
+ if (flat_views) {
+ g_hash_table_unref(flat_views);
+ flat_views = NULL;
+ }
+ flatviews_init();
+
+ /* Render unique FVs */
+ QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
+ MemoryRegion *physmr = 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 = address_space_get_flatview(as);
- MemoryRegion *physmr = memory_region_get_flatview_root(old_view->root);
- FlatView *new_view = generate_memory_topology(physmr);
+ MemoryRegion *physmr = memory_region_get_flatview_root(as->root);
+ FlatView *new_view = g_hash_table_lookup(flat_views, physmr);
+
+ assert(new_view);
+
+ flatview_ref(new_view);
if (!QTAILQ_EMPTY(&as->listeners)) {
address_space_update_topology_pass(as, old_view, new_view, false);
@@ -969,10 +1008,12 @@ 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);
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 = false;
@@ -2695,13 +2736,6 @@ AddressSpace *address_space_init_shareable(MemoryRegion
*root, const char *name)
{
AddressSpace *as;
- QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
- if (root == as->root && as->malloced) {
- as->ref_count++;
- return as;
- }
- }
-
as = g_malloc0(sizeof *as);
address_space_init(as, root, name);
as->malloced = true;
--
2.11.0
- [Qemu-stable] [PATCH 00/55] Patch Round-up for stable 2.10.2, freeze on 2017-12-13, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 10/55] memory: Remove AddressSpace pointer from AddressSpaceDispatch, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 09/55] memory: Move AddressSpaceDispatch from AddressSpace to FlatView, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 11/55] memory: avoid "resurrection" of dead FlatViews, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 14/55] memory: Rename mem_begin/mem_commit/mem_add helpers, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 12/55] memory: Switch memory from using AddressSpace to FlatView, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 16/55] memory: Alloc dispatch tree where topology is generared, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 18/55] memory: Share FlatView's and dispatch trees between address spaces,
Michael Roth <=
- [Qemu-stable] [PATCH 20/55] memory: Get rid of address_space_init_shareable, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 15/55] memory: Store physical root MR in FlatView, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 13/55] memory: Cleanup after switching to FlatView, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 17/55] memory: Move address_space_update_ioeventfds, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 19/55] memory: Do not allocate FlatView in address_space_init, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 21/55] memory: Create FlatView directly, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 01/55] hw/ppc: CAS reset on early device hotplug, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 22/55] memory: trace FlatView creation and destruction, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 23/55] memory: seek FlatView sharing candidates among children subregions, Michael Roth, 2017/12/06
- [Qemu-stable] [PATCH 26/55] exec: simplify address_space_get_iotlb_entry, Michael Roth, 2017/12/06