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[Qemu-devel] [PATCH v3 21/29] exec: only check relevant bitmaps for clea
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH v3 21/29] exec: only check relevant bitmaps for cleanliness |
Date: |
Tue, 26 May 2015 18:54:57 +0200 |
Most of the time, not all bitmaps have to be marked as dirty;
do not do anything if the interesting ones are already dirty.
Previously, any clean bitmap would have cause all the bitmaps to be
marked dirty.
In fact, unless running TCG most of the time bitmap operations need
not be done at all, because memory_region_is_logging returns zero.
In this case, skip the call to cpu_physical_memory_range_includes_clean
altogether as well.
With this patch, cpu_physical_memory_set_dirty_range is called
unconditionally, so there need not be anymore a separate call to
xen_modified_memory.
Reviewed-by: Fam Zheng <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
exec.c | 22 +++++++++++++---------
include/exec/ram_addr.h | 25 ++++++++++++++++++-------
2 files changed, 31 insertions(+), 16 deletions(-)
diff --git a/exec.c b/exec.c
index 9d342fe..4cd18ff 100644
--- a/exec.c
+++ b/exec.c
@@ -2263,16 +2263,20 @@ int cpu_memory_rw_debug(CPUState *cpu, target_ulong
addr,
static void invalidate_and_set_dirty(MemoryRegion *mr, hwaddr addr,
hwaddr length)
{
- if (cpu_physical_memory_range_includes_clean(addr, length)) {
- uint8_t dirty_log_mask = memory_region_get_dirty_log_mask(mr);
- if (dirty_log_mask & (1 << DIRTY_MEMORY_CODE)) {
- tb_invalidate_phys_range(addr, addr + length);
- dirty_log_mask &= ~(1 << DIRTY_MEMORY_CODE);
- }
- cpu_physical_memory_set_dirty_range(addr, length, dirty_log_mask);
- } else {
- xen_modified_memory(addr, length);
+ uint8_t dirty_log_mask = memory_region_get_dirty_log_mask(mr);
+ /* No early return if dirty_log_mask is or becomes 0, because
+ * cpu_physical_memory_set_dirty_range will still call
+ * xen_modified_memory.
+ */
+ if (dirty_log_mask) {
+ dirty_log_mask =
+ cpu_physical_memory_range_includes_clean(addr, length,
dirty_log_mask);
+ }
+ if (dirty_log_mask & (1 << DIRTY_MEMORY_CODE)) {
+ tb_invalidate_phys_range(addr, addr + length);
+ dirty_log_mask &= ~(1 << DIRTY_MEMORY_CODE);
}
+ cpu_physical_memory_set_dirty_range(addr, length, dirty_log_mask);
}
static int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr)
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 4e3b081..9778398 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -89,14 +89,25 @@ static inline bool cpu_physical_memory_is_clean(ram_addr_t
addr)
return !(vga && code && migration);
}
-static inline bool cpu_physical_memory_range_includes_clean(ram_addr_t start,
- ram_addr_t length)
+static inline uint8_t cpu_physical_memory_range_includes_clean(ram_addr_t
start,
+ ram_addr_t
length,
+ uint8_t mask)
{
- bool vga = !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA);
- bool code = !cpu_physical_memory_all_dirty(start, length,
DIRTY_MEMORY_CODE);
- bool migration =
- !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION);
- return vga || code || migration;
+ uint8_t ret = 0;
+
+ if (mask & (1 << DIRTY_MEMORY_VGA) &&
+ !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA)) {
+ ret |= (1 << DIRTY_MEMORY_VGA);
+ }
+ if (mask & (1 << DIRTY_MEMORY_CODE) &&
+ !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_CODE)) {
+ ret |= (1 << DIRTY_MEMORY_CODE);
+ }
+ if (mask & (1 << DIRTY_MEMORY_MIGRATION) &&
+ !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION))
{
+ ret |= (1 << DIRTY_MEMORY_MIGRATION);
+ }
+ return ret;
}
static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
--
1.8.3.1
- [Qemu-devel] [PATCH v3 04/29] display: add memory_region_sync_dirty_bitmap calls, (continued)
- [Qemu-devel] [PATCH v3 04/29] display: add memory_region_sync_dirty_bitmap calls, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 15/29] exec: move functions to translate-all.h, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 23/29] bitmap: add atomic set functions, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 19/29] exec: pass client mask to cpu_physical_memory_set_dirty_range, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 07/29] framebuffer: check memory_region_is_logging, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 11/29] memory: include DIRTY_MEMORY_MIGRATION in the dirty log mask, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 16/29] translate-all: remove unnecessary argument to tb_invalidate_phys_range, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 21/29] exec: only check relevant bitmaps for cleanliness,
Paolo Bonzini <=
- [Qemu-devel] [PATCH v3 24/29] bitmap: add atomic test and clear, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 14/29] exec: use memory_region_get_dirty_log_mask to optimize dirty tracking, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 25/29] memory: use atomic ops for setting dirty memory bits, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 06/29] memory: prepare for multiple bits in the dirty log mask, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 17/29] cputlb: remove useless arguments to tlb_unprotect_code_phys, rename, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 26/29] migration: move dirty bitmap sync to ram_addr.h, Paolo Bonzini, 2015/05/26
- [Qemu-devel] [PATCH v3 12/29] kvm: remove special handling of DIRTY_MEMORY_MIGRATION in the dirty log mask, Paolo Bonzini, 2015/05/26