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[Qemu-devel] [PULL 18/32] memory: Do not allocate FlatView in address_sp
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 18/32] memory: Do not allocate FlatView in address_space_init |
Date: |
Fri, 22 Sep 2017 01:16:26 +0200 |
From: Alexey Kardashevskiy <address@hidden>
This creates a new AS object without any FlatView as
memory_region_transaction_commit() may want to reuse the empty FV.
Signed-off-by: Alexey Kardashevskiy <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
memory.c | 29 +++++++++++++++++++++++------
1 file changed, 23 insertions(+), 6 deletions(-)
diff --git a/memory.c b/memory.c
index 8ee3c81..3f6dd40 100644
--- a/memory.c
+++ b/memory.c
@@ -967,22 +967,37 @@ static void flatviews_reset(void)
static void address_space_set_flatview(AddressSpace *as)
{
- FlatView *old_view = address_space_get_flatview(as);
+ FlatView *old_view = address_space_to_flatview(as);
MemoryRegion *physmr = memory_region_get_flatview_root(as->root);
FlatView *new_view = g_hash_table_lookup(flat_views, physmr);
assert(new_view);
+ if (old_view == new_view) {
+ return;
+ }
+
+ if (old_view) {
+ flatview_ref(old_view);
+ }
+
flatview_ref(new_view);
if (!QTAILQ_EMPTY(&as->listeners)) {
- address_space_update_topology_pass(as, old_view, new_view, false);
- address_space_update_topology_pass(as, old_view, new_view, true);
+ FlatView tmpview = { .nr = 0 }, *old_view2 = old_view;
+
+ if (!old_view2) {
+ old_view2 = &tmpview;
+ }
+ address_space_update_topology_pass(as, old_view2, new_view, false);
+ address_space_update_topology_pass(as, old_view2, new_view, true);
}
/* Writes are protected by the BQL. */
atomic_rcu_set(&as->current_map, new_view);
- flatview_unref(old_view);
+ if (old_view) {
+ flatview_unref(old_view);
+ }
/* Note that all the old MemoryRegions are still alive up to this
* point. This relieves most MemoryListeners from the need to
@@ -990,7 +1005,9 @@ static void address_space_set_flatview(AddressSpace *as)
* outside the iothread mutex, in which case precise reference
* counting is necessary.
*/
- flatview_unref(old_view);
+ if (old_view) {
+ flatview_unref(old_view);
+ }
}
void memory_region_transaction_begin(void)
@@ -2708,7 +2725,7 @@ void address_space_init(AddressSpace *as, MemoryRegion
*root, const char *name)
as->ref_count = 1;
as->root = root;
as->malloced = false;
- as->current_map = flatview_new(root);
+ as->current_map = NULL;
as->ioeventfd_nb = 0;
as->ioeventfds = NULL;
QTAILQ_INIT(&as->listeners);
--
1.8.3.1
- [Qemu-devel] [PULL 05/32] memory: avoid "resurrection" of dead FlatViews, (continued)
- [Qemu-devel] [PULL 05/32] memory: avoid "resurrection" of dead FlatViews, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 10/32] memory: Remove AddressSpace pointer from AddressSpaceDispatch, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 09/32] memory: Move AddressSpaceDispatch from AddressSpace to FlatView, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 13/32] memory: Rename mem_begin/mem_commit/mem_add helpers, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 12/32] memory: Cleanup after switching to FlatView, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 14/32] memory: Store physical root MR in FlatView, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 15/32] memory: Alloc dispatch tree where topology is generared, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 11/32] memory: Switch memory from using AddressSpace to FlatView, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 16/32] memory: Move address_space_update_ioeventfds, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 17/32] memory: Share FlatView's and dispatch trees between address spaces, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 18/32] memory: Do not allocate FlatView in address_space_init,
Paolo Bonzini <=
- [Qemu-devel] [PULL 21/32] memory: Create FlatView directly, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 23/32] memory: seek FlatView sharing candidates among children subregions, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 20/32] memory: Get rid of address_space_init_shareable, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 22/32] memory: trace FlatView creation and destruction, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 19/32] memory: Rework "info mtree" to print flat views and dispatch trees, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 24/32] memory: Share special empty FlatView, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 25/32] scsi, file-posix: add support for persistent reservation management, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 29/32] chardev: new qemu_chr_be_update_read_handlers(), Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 28/32] scsi: add persistent reservation manager using qemu-pr-helper, Paolo Bonzini, 2017/09/21
- [Qemu-devel] [PULL 30/32] chardev: add Chardev.gcontext field, Paolo Bonzini, 2017/09/21