From: xuchuangxclwt <[email protected]> When the addresses processed are not aligned, a large number of clear_dirty ioctl occur (e.g. a 16MB misaligned memory can generate 4096 clear_dirty ioctls), which increases the time required for bitmap_sync and makes it more difficult for dirty pages to converge.
Attempt to merge those fragmented clear_dirty ioctls. Signed-off-by: Chuang Xu <[email protected]> --- accel/tcg/cputlb.c | 5 +++-- include/system/physmem.h | 3 ++- migration/ram.c | 17 ++++++++++++++++- system/memory.c | 2 +- system/physmem.c | 19 +++++++++++-------- 5 files changed, 33 insertions(+), 13 deletions(-) diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c index fd1606c856..8a054cb545 100644 --- a/accel/tcg/cputlb.c +++ b/accel/tcg/cputlb.c @@ -857,8 +857,9 @@ void tlb_flush_page_bits_by_mmuidx_all_cpus_synced(CPUState *src_cpu, void tlb_protect_code(ram_addr_t ram_addr) { physical_memory_test_and_clear_dirty(ram_addr & TARGET_PAGE_MASK, - TARGET_PAGE_SIZE, - DIRTY_MEMORY_CODE); + TARGET_PAGE_SIZE, + DIRTY_MEMORY_CODE, + true); } /* update the TLB so that writes in physical page 'phys_addr' are no longer diff --git a/include/system/physmem.h b/include/system/physmem.h index 879f6eae38..8529f0510a 100644 --- a/include/system/physmem.h +++ b/include/system/physmem.h @@ -41,7 +41,8 @@ void physical_memory_dirty_bits_cleared(ram_addr_t start, ram_addr_t length); bool physical_memory_test_and_clear_dirty(ram_addr_t start, ram_addr_t length, - unsigned client); + unsigned client, + bool clear_dirty); DirtyBitmapSnapshot * physical_memory_snapshot_and_clear_dirty(MemoryRegion *mr, hwaddr offset, diff --git a/migration/ram.c b/migration/ram.c index 29f016cb25..329168d081 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -995,18 +995,33 @@ static uint64_t physical_memory_sync_dirty_bitmap(RAMBlock *rb, } } else { ram_addr_t offset = rb->offset; + unsigned long end, start_page; + uint64_t mr_offset, mr_size; for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) { + /* + * Here we don't expect so many clear_dirty, so we call + * physical_memory_test_and_clear_dirty with clear_dirty + * set to false. Later we'll do make an overall clear_dirty + * outside the loop. + */ if (physical_memory_test_and_clear_dirty( start + addr + offset, TARGET_PAGE_SIZE, - DIRTY_MEMORY_MIGRATION)) { + DIRTY_MEMORY_MIGRATION, + false)) { long k = (start + addr) >> TARGET_PAGE_BITS; if (!test_and_set_bit(k, dest)) { num_dirty++; } } } + end = TARGET_PAGE_ALIGN(start + addr + offset + TARGET_PAGE_SIZE) + >> TARGET_PAGE_BITS; + start_page = (start + offset) >> TARGET_PAGE_BITS; + mr_offset = (ram_addr_t)(start_page << TARGET_PAGE_BITS) - offset; + mr_size = (end - start_page) << TARGET_PAGE_BITS; + memory_region_clear_dirty_bitmap(rb->mr, mr_offset, mr_size); } return num_dirty; diff --git a/system/memory.c b/system/memory.c index 8b84661ae3..7b81b84f30 100644 --- a/system/memory.c +++ b/system/memory.c @@ -2424,7 +2424,7 @@ void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr, { assert(mr->ram_block); physical_memory_test_and_clear_dirty( - memory_region_get_ram_addr(mr) + addr, size, client); + memory_region_get_ram_addr(mr) + addr, size, client, true); } int memory_region_get_fd(MemoryRegion *mr) diff --git a/system/physmem.c b/system/physmem.c index c9869e4049..21b2db3884 100644 --- a/system/physmem.c +++ b/system/physmem.c @@ -1091,8 +1091,9 @@ void physical_memory_set_dirty_range(ram_addr_t start, ram_addr_t length, /* Note: start and end must be within the same ram block. */ bool physical_memory_test_and_clear_dirty(ram_addr_t start, - ram_addr_t length, - unsigned client) + ram_addr_t length, + unsigned client, + bool clear_dirty) { DirtyMemoryBlocks *blocks; unsigned long end, page, start_page; @@ -1126,9 +1127,11 @@ bool physical_memory_test_and_clear_dirty(ram_addr_t start, page += num; } - mr_offset = (ram_addr_t)(start_page << TARGET_PAGE_BITS) - ramblock->offset; - mr_size = (end - start_page) << TARGET_PAGE_BITS; - memory_region_clear_dirty_bitmap(ramblock->mr, mr_offset, mr_size); + if (clear_dirty) { + mr_offset = (ram_addr_t)(start_page << TARGET_PAGE_BITS) - ramblock->offset; + mr_size = (end - start_page) << TARGET_PAGE_BITS; + memory_region_clear_dirty_bitmap(ramblock->mr, mr_offset, mr_size); + } } if (dirty) { @@ -1140,9 +1143,9 @@ bool physical_memory_test_and_clear_dirty(ram_addr_t start, static void physical_memory_clear_dirty_range(ram_addr_t addr, ram_addr_t length) { - physical_memory_test_and_clear_dirty(addr, length, DIRTY_MEMORY_MIGRATION); - physical_memory_test_and_clear_dirty(addr, length, DIRTY_MEMORY_VGA); - physical_memory_test_and_clear_dirty(addr, length, DIRTY_MEMORY_CODE); + physical_memory_test_and_clear_dirty(addr, length, DIRTY_MEMORY_MIGRATION, true); + physical_memory_test_and_clear_dirty(addr, length, DIRTY_MEMORY_VGA, true); + physical_memory_test_and_clear_dirty(addr, length, DIRTY_MEMORY_CODE, true); } DirtyBitmapSnapshot *physical_memory_snapshot_and_clear_dirty -- 2.20.1
