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Re: [Qemu-devel] [PATCH 5/5] migration: refine ram_save_compressed_page
From: |
Juan Quintela |
Subject: |
Re: [Qemu-devel] [PATCH 5/5] migration: refine ram_save_compressed_page |
Date: |
Wed, 04 May 2016 11:33:09 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) |
Liang Li <address@hidden> wrote:
> Use qemu_put_compression_data to do the compression directly
> instead of using do_compress_ram_page, avoid some data copy.
> very small improvement, at the same time, add code to check
> if the compression is successful.
>
> Signed-off-by: Liang Li <address@hidden>
> ---
> migration/ram.c | 28 +++++++++++++---------------
> 1 file changed, 13 insertions(+), 15 deletions(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index 7e62d8d..ec2c0bf 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -927,24 +927,20 @@ static int ram_save_compressed_page(QEMUFile *f,
> PageSearchStatus *pss,
> uint64_t *bytes_transferred)
> {
> int pages = -1;
> - uint64_t bytes_xmit;
> + uint64_t bytes_xmit = 0;
> uint8_t *p;
> - int ret;
> + int ret, blen;
> RAMBlock *block = pss->block;
> ram_addr_t offset = pss->offset;
>
> p = block->host + offset;
>
> - bytes_xmit = 0;
> ret = ram_control_save_page(f, block->offset,
> offset, TARGET_PAGE_SIZE, &bytes_xmit);
> if (bytes_xmit) {
> *bytes_transferred += bytes_xmit;
> pages = 1;
> }
> - if (block == last_sent_block) {
> - offset |= RAM_SAVE_FLAG_CONTINUE;
> - }
> if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
> if (ret != RAM_SAVE_CONTROL_DELAYED) {
> if (bytes_xmit > 0) {
> @@ -964,17 +960,19 @@ static int ram_save_compressed_page(QEMUFile *f,
> PageSearchStatus *pss,
> flush_compressed_data(f);
> pages = save_zero_page(f, block, offset, p, bytes_transferred);
> if (pages == -1) {
> - set_compress_params(&comp_param[0], block, offset);
> - /* Use the qemu thread to compress the data to make sure the
> - * first page is sent out before other pages
> - */
> - bytes_xmit = do_compress_ram_page(&comp_param[0]);
> - acct_info.norm_pages++;
> - qemu_put_qemu_file(f, comp_param[0].file);
> - *bytes_transferred += bytes_xmit;
> - pages = 1;
> + /* Make sure the first page is sent out before other pages */
> + bytes_xmit = save_page_header(f, block, offset |
> + RAM_SAVE_FLAG_COMPRESS_PAGE);
> + blen = qemu_put_compression_data(f, p, TARGET_PAGE_SIZE,
> + migrate_compress_level());
> + if (blen > 0) {
> + *bytes_transferred += bytes_xmit + blen;
> + acct_info.norm_pages++;
> + pages = 1;
> + }
> }
> } else {
> + offset |= RAM_SAVE_FLAG_CONTINUE;
> pages = save_zero_page(f, block, offset, p, bytes_transferred);
> if (pages == -1) {
> pages = compress_page_with_multi_thread(f, block, offset,
You need to decide what to do when blen <= 0. As said in previous
patch, I can only think of aborting migration. But ignoring the error
is not an option IMHO.
Later, Juan.
- [Qemu-devel] [PATCH 0/5] live migration bug fix and refine, Liang Li, 2016/05/03
- [Qemu-devel] [PATCH 1/5] migration: Fix multi-thread compression bug, Liang Li, 2016/05/03
- [Qemu-devel] [PATCH 3/5] migration: remove useless code, Liang Li, 2016/05/03
- [Qemu-devel] [PATCH 5/5] migration: refine ram_save_compressed_page, Liang Li, 2016/05/03
- Re: [Qemu-devel] [PATCH 5/5] migration: refine ram_save_compressed_page,
Juan Quintela <=
- [Qemu-devel] [PATCH 2/5] migration: Fix a potential issue, Liang Li, 2016/05/03
- [Qemu-devel] [PATCH 4/5] qemu-file: Fix qemu_put_compression_data flaw, Liang Li, 2016/05/03