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[Qemu-devel] [PULL 11/11] memory: Don't call memory_region_update_coales
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 11/11] memory: Don't call memory_region_update_coalesced_range if nothing changed |
Date: |
Wed, 18 Jun 2014 15:42:08 +0200 |
From: Fam Zheng <address@hidden>
With huge number of PCI devices in the system (for example, 200
virtio-blk-pci), this unconditional call can slow down emulation of
irrelevant PCI operations drastically, such as a BAR update on a device
that has no coalescing region. So avoid it.
Signed-off-by: Fam Zheng <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
memory.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/memory.c b/memory.c
index 85798b0..4895e25 100644
--- a/memory.c
+++ b/memory.c
@@ -1332,6 +1332,7 @@ void memory_region_add_coalescing(MemoryRegion *mr,
void memory_region_clear_coalescing(MemoryRegion *mr)
{
CoalescedMemoryRange *cmr;
+ bool updated = false;
qemu_flush_coalesced_mmio_buffer();
mr->flush_coalesced_mmio = false;
@@ -1340,8 +1341,12 @@ void memory_region_clear_coalescing(MemoryRegion *mr)
cmr = QTAILQ_FIRST(&mr->coalesced);
QTAILQ_REMOVE(&mr->coalesced, cmr, link);
g_free(cmr);
+ updated = true;
+ }
+
+ if (updated) {
+ memory_region_update_coalesced_range(mr);
}
- memory_region_update_coalesced_range(mr);
}
void memory_region_set_flush_coalesced(MemoryRegion *mr)
--
1.8.3.1
- [Qemu-devel] [PULL 00/11] Memory API changes for 2014-06-18, Paolo Bonzini, 2014/06/18
- [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 <=
- [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, 2014/06/18
- Re: [Qemu-devel] [PULL 00/11] Memory API changes for 2014-06-18, Peter Maydell, 2014/06/18