On Tue, Jul 24, 2012 at 08:36:29PM +0200, Juan Quintela wrote:
> From: Umesh Deshpande <[email protected]>
>
> This will be used to detect if last_block might have become invalid
> across different calls to ram_save_live.
>
> Signed-off-by: Paolo Bonzini <[email protected]>
> Signed-off-by: Umesh Deshpande <[email protected]>
> Signed-off-by: Juan Quintela <[email protected]>
> ---
> arch_init.c | 6 ++++++
> cpu-all.h | 1 +
> exec.c | 4 ++++
> 3 files changed, 11 insertions(+)
>
> diff --git a/arch_init.c b/arch_init.c
> index 02d36ce..9e05aae 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -340,6 +340,7 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t
> *current_data,
>
> static RAMBlock *last_block;
> static ram_addr_t last_offset;
> +static uint32_t last_version;
>
> /*
> * ram_save_block: Writes a page of memory to the stream f
> @@ -496,6 +497,7 @@ static void reset_ram_globals(void)
> {
> last_block = NULL;
> last_offset = 0;
> + last_version = ram_list.version;
> sort_ram_list();
> }
>
> @@ -554,6 +556,10 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
> int i;
> uint64_t expected_time;
>
> + if (ram_list.version != last_version) {
> + reset_ram_globals();
> + }
> +
Was it a bug in the old code to not do this? In the unthreaded version
it looks like last_block could still become invalid between iterations if it
was removed in the meantime, so I'm trying to understand why it's needed
now.
And why do we re-sort when this happens? The old implementation didn't
seem to place any guarantees on the block ordering beyond the initial
sorting by block->idstr. After that they were sent in MRU order.
> bytes_transferred_last = bytes_transferred;
> bwidth = qemu_get_clock_ns(rt_clock);
>
> diff --git a/cpu-all.h b/cpu-all.h
> index ca3bb24..429b2c6 100644
> --- a/cpu-all.h
> +++ b/cpu-all.h
> @@ -486,6 +486,7 @@ typedef struct RAMBlock {
>
> typedef struct RAMList {
> uint8_t *phys_dirty;
> + uint32_t version;
> QLIST_HEAD(, RAMBlock) blocks_mru;
> QLIST_HEAD(, RAMBlock) blocks;
> uint64_t dirty_pages;
> diff --git a/exec.c b/exec.c
> index afc472f..ceffa4f 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -2555,6 +2555,8 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size,
> void *host,
> QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
> QLIST_INSERT_HEAD(&ram_list.blocks_mru, new_block, next_mru);
>
> + ram_list.version++;
> +
> ram_list.phys_dirty = g_realloc(ram_list.phys_dirty,
> last_ram_offset() >>
> TARGET_PAGE_BITS);
> cpu_physical_memory_set_dirty_range(new_block->offset, size, 0xff);
> @@ -2578,6 +2580,7 @@ void qemu_ram_free_from_ptr(ram_addr_t addr)
> if (addr == block->offset) {
> QLIST_REMOVE(block, next);
> QLIST_REMOVE(block, next_mru);
> + ram_list.version++;
> g_free(block);
> return;
> }
> @@ -2592,6 +2595,7 @@ void qemu_ram_free(ram_addr_t addr)
> if (addr == block->offset) {
> QLIST_REMOVE(block, next);
> QLIST_REMOVE(block, next_mru);
> + ram_list.version++;
> if (block->flags & RAM_PREALLOC_MASK) {
> ;
> } else if (mem_path) {
> --
> 1.7.10.4
>
>
