Hi Juan
This patch will make my work more difficult, as we discussed before, after
modification,
I have to use a lock before I can reuse the function save_block_hdr in my
compression threads,
this will lead to low efficiency. Could help to revert this patch?
Liang
> -----Original Message-----
> From: qemu-devel-bounces+liang.z.li=intel....@nongnu.org [mailto:qemu-
> devel-bounces+liang.z.li=intel....@nongnu.org] On Behalf Of Juan Quintela
> Sent: Monday, March 16, 2015 9:41 PM
> To: qemu-devel@nongnu.org
> Subject: [Qemu-devel] [PULL 07/11] save_block_hdr: we can recalculate the
> cont parameter here
>
> No need to pass it through all the callers. Once there, update
> last_sent_block here.
>
> Signed-off-by: Juan Quintela <quint...@redhat.com>
> ---
> arch_init.c | 47 ++++++++++++++++++++++++-----------------------
> 1 file changed, 24 insertions(+), 23 deletions(-)
>
> diff --git a/arch_init.c b/arch_init.c
> index d30fd13..7377a07 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -305,34 +305,39 @@ uint64_t xbzrle_mig_pages_overflow(void)
> return acct_info.xbzrle_overflows;
> }
>
> +/* This is the last block that we have visited serching for dirty pages
> +*/ static RAMBlock *last_seen_block;
> +/* This is the last block from where we have sent data */ static
> +RAMBlock *last_sent_block; static ram_addr_t last_offset; static
> +unsigned long *migration_bitmap; static uint64_t migration_dirty_pages;
> +static uint32_t last_version; static bool ram_bulk_stage;
> +
> static size_t save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t
> offset,
> - int cont, int flag)
> + int flag)
> {
> size_t size;
>
> - qemu_put_be64(f, offset | cont | flag);
> + if (block == last_sent_block) {
> + offset |= RAM_SAVE_FLAG_CONTINUE;
> + }
> +
> + qemu_put_be64(f, offset | flag);
> size = 8;
>
> - if (!cont) {
> + if (block != last_sent_block) {
> qemu_put_byte(f, strlen(block->idstr));
> qemu_put_buffer(f, (uint8_t *)block->idstr,
> strlen(block->idstr));
> size += 1 + strlen(block->idstr);
> + last_sent_block = block;
> }
> return size;
> }
>
> -/* This is the last block that we have visited serching for dirty pages
> - */
> -static RAMBlock *last_seen_block;
> -/* This is the last block from where we have sent data */ -static RAMBlock
> *last_sent_block; -static ram_addr_t last_offset; -static unsigned long
> *migration_bitmap; -static uint64_t migration_dirty_pages; -static uint32_t
> last_version; -static bool ram_bulk_stage;
> -
> /* Update the xbzrle cache to reflect a page that's been sent as all 0.
> * The important thing is that a stale (not-yet-0'd) page be replaced
> * by the new data.
> @@ -370,7 +375,7 @@ static void xbzrle_cache_zero_page(ram_addr_t
> current_addr)
> */
> static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
> ram_addr_t current_addr, RAMBlock *block,
> - ram_addr_t offset, int cont, bool last_stage,
> + ram_addr_t offset, bool last_stage,
> uint64_t *bytes_transferred) {
> int encoded_len = 0, bytes_xbzrle;
> @@ -420,7 +425,7 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t
> **current_data,
> }
>
> /* Send XBZRLE based compressed page */
> - bytes_xbzrle = save_block_hdr(f, block, offset, cont,
> RAM_SAVE_FLAG_XBZRLE);
> + bytes_xbzrle = save_block_hdr(f, block, offset,
> + RAM_SAVE_FLAG_XBZRLE);
> qemu_put_byte(f, ENCODING_FLAG_XBZRLE);
> qemu_put_be16(f, encoded_len);
> qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len); @@ -608,15
> +613,12 @@ static int ram_save_page(QEMUFile *f, RAMBlock* block,
> ram_addr_t offset, {
> int pages = -1;
> uint64_t bytes_xmit;
> - int cont;
> ram_addr_t current_addr;
> MemoryRegion *mr = block->mr;
> uint8_t *p;
> int ret;
> bool send_async = true;
>
> - cont = (block == last_sent_block) ? RAM_SAVE_FLAG_CONTINUE : 0;
> -
> p = memory_region_get_ram_ptr(mr) + offset;
>
> /* In doubt sent page as normal */
> @@ -641,7 +643,7 @@ static int ram_save_page(QEMUFile *f, RAMBlock*
> block, ram_addr_t offset,
> }
> } else if (is_zero_range(p, TARGET_PAGE_SIZE)) {
> acct_info.dup_pages++;
> - *bytes_transferred += save_block_hdr(f, block, offset, cont,
> + *bytes_transferred += save_block_hdr(f, block, offset,
> RAM_SAVE_FLAG_COMPRESS);
> qemu_put_byte(f, 0);
> *bytes_transferred += 1;
> @@ -652,7 +654,7 @@ static int ram_save_page(QEMUFile *f, RAMBlock*
> block, ram_addr_t offset,
> xbzrle_cache_zero_page(current_addr);
> } else if (!ram_bulk_stage && migrate_use_xbzrle()) {
> pages = save_xbzrle_page(f, &p, current_addr, block,
> - offset, cont, last_stage,
> bytes_transferred);
> + offset, last_stage,
> + bytes_transferred);
> if (!last_stage) {
> /* Can't send this cached data async, since the cache page
> * might get updated before it gets to the wire @@ -663,7 +665,7
> @@
> static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
>
> /* XBZRLE overflow or normal page */
> if (pages == -1) {
> - *bytes_transferred += save_block_hdr(f, block, offset, cont,
> + *bytes_transferred += save_block_hdr(f, block, offset,
> RAM_SAVE_FLAG_PAGE);
> if (send_async) {
> qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE); @@ -726,7 +728,6
> @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
>
> /* if page is unmodified, continue to the next */
> if (pages > 0) {
> - last_sent_block = block;
> break;
> }
> }
> --
> 2.1.0
>
