[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PULL 04/11] memory: Don't update all memory region when io
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 04/11] memory: Don't update all memory region when ioeventfd changed |
Date: |
Wed, 18 Jun 2014 15:42:01 +0200 |
From: Gonglei <address@hidden>
memory mappings don't rely on ioeventfds, there is no need
to destroy and rebuild them when manipulating ioeventfds,
otherwise it scarifies performance.
according to testing result, each ioeventfd deleing needs
about 5ms, within which memory mapping rebuilding needs
about 4ms. With many Nics and vmchannel in a VM doing migrating,
there can be many ioeventfds deleting which increasing
downtime remarkably.
Signed-off-by: Gonglei <address@hidden>
Signed-off-by: Herongguang <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
memory.c | 33 +++++++++++++++++++++++----------
1 file changed, 23 insertions(+), 10 deletions(-)
diff --git a/memory.c b/memory.c
index 678661e..829d56d 100644
--- a/memory.c
+++ b/memory.c
@@ -28,6 +28,7 @@
static unsigned memory_region_transaction_depth;
static bool memory_region_update_pending;
+static bool ioeventfd_update_pending;
static bool global_dirty_log = false;
/* flat_view_mutex is taken around reading as->current_map; the critical
@@ -786,22 +787,34 @@ void memory_region_transaction_begin(void)
++memory_region_transaction_depth;
}
+static void memory_region_clear_pending(void)
+{
+ memory_region_update_pending = false;
+ ioeventfd_update_pending = false;
+}
+
void memory_region_transaction_commit(void)
{
AddressSpace *as;
assert(memory_region_transaction_depth);
--memory_region_transaction_depth;
- if (!memory_region_transaction_depth && memory_region_update_pending) {
- memory_region_update_pending = false;
- MEMORY_LISTENER_CALL_GLOBAL(begin, Forward);
+ if (!memory_region_transaction_depth) {
+ if (memory_region_update_pending) {
+ MEMORY_LISTENER_CALL_GLOBAL(begin, Forward);
- QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
- address_space_update_topology(as);
- }
+ QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
+ address_space_update_topology(as);
+ }
- MEMORY_LISTENER_CALL_GLOBAL(commit, Forward);
- }
+ MEMORY_LISTENER_CALL_GLOBAL(commit, Forward);
+ } else if (ioeventfd_update_pending) {
+ QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
+ address_space_update_ioeventfds(as);
+ }
+ }
+ memory_region_clear_pending();
+ }
}
static void memory_region_destructor_none(MemoryRegion *mr)
@@ -1373,7 +1386,7 @@ void memory_region_add_eventfd(MemoryRegion *mr,
memmove(&mr->ioeventfds[i+1], &mr->ioeventfds[i],
sizeof(*mr->ioeventfds) * (mr->ioeventfd_nb-1 - i));
mr->ioeventfds[i] = mrfd;
- memory_region_update_pending |= mr->enabled;
+ ioeventfd_update_pending |= mr->enabled;
memory_region_transaction_commit();
}
@@ -1406,7 +1419,7 @@ void memory_region_del_eventfd(MemoryRegion *mr,
--mr->ioeventfd_nb;
mr->ioeventfds = g_realloc(mr->ioeventfds,
sizeof(*mr->ioeventfds)*mr->ioeventfd_nb +
1);
- memory_region_update_pending |= mr->enabled;
+ ioeventfd_update_pending |= mr->enabled;
memory_region_transaction_commit();
}
--
1.8.3.1
- [Qemu-devel] [PULL 01/11] MAINTAINERS: Add myself as Memory API maintainer, (continued)
- [Qemu-devel] [PULL 01/11] MAINTAINERS: Add myself as Memory API maintainer, Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 02/11] exec: introduce qemu_ram_unset_idstr() to unset RAMBlock idstr, Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 05/11] memory: Simplify mr_add_subregion() if-else, Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 06/11] exec: dummy_section: Pass address space through., Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 09/11] memory: MemoryRegion: factor out memory region re-adder, Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 08/11] memory: MemoryRegion: factor out subregion add functionality, Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 07/11] qtest: fix qtest_clock_warp() for no deadline case, Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 10/11] memory: MemoryRegion: rename parent to container, Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 11/11] memory: Don't call memory_region_update_coalesced_range if nothing changed, Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 03/11] unset RAMBlock idstr when unregister MemoryRegion, Paolo Bonzini, 2014/06/18
- [Qemu-devel] [PULL 04/11] memory: Don't update all memory region when ioeventfd changed,
Paolo Bonzini <=
- Re: [Qemu-devel] [PULL 00/11] Memory API changes for 2014-06-18, Peter Maydell, 2014/06/18