* Juan Quintela (quint...@redhat.com) wrote:
> The function still don't use multifd, but we have simplified
> ram_save_page, xbzrle and RDMA stuff is gone. We have added a new
> counter and a new flag for this type of pages.
>
> Signed-off-by: Juan Quintela <quint...@redhat.com>
> ---
> hmp.c | 2 ++
> include/migration/migration.h | 1 +
> migration/migration.c | 1 +
> migration/ram.c | 51
> ++++++++++++++++++++++++++++++++++++++++++-
> qapi-schema.json | 4 +++-
> 5 files changed, 57 insertions(+), 2 deletions(-)
>
> diff --git a/hmp.c b/hmp.c
> index e579766..76bc8c7 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -222,6 +222,8 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
> monitor_printf(mon, "postcopy request count: %" PRIu64 "\n",
> info->ram->postcopy_requests);
> }
> + monitor_printf(mon, "multifd: %" PRIu64 " pages\n",
> + info->ram->multifd);
> }
>
> if (info->has_disk) {
> diff --git a/include/migration/migration.h b/include/migration/migration.h
> index 3989bd6..b3e4f31 100644
> --- a/include/migration/migration.h
> +++ b/include/migration/migration.h
> @@ -282,6 +282,7 @@ uint64_t xbzrle_mig_pages_transferred(void);
> uint64_t xbzrle_mig_pages_overflow(void);
> uint64_t xbzrle_mig_pages_cache_miss(void);
> double xbzrle_mig_cache_miss_rate(void);
> +uint64_t multifd_mig_pages_transferred(void);
>
> void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
> void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
> diff --git a/migration/migration.c b/migration/migration.c
> index ab48f06..1d62b91 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -652,6 +652,7 @@ static void populate_ram_info(MigrationInfo *info,
> MigrationState *s)
> info->ram->mbps = s->mbps;
> info->ram->dirty_sync_count = s->dirty_sync_count;
> info->ram->postcopy_requests = s->postcopy_requests;
> + info->ram->multifd = multifd_mig_pages_transferred();
>
> if (s->state != MIGRATION_STATUS_COMPLETED) {
> info->ram->remaining = ram_bytes_remaining();
> diff --git a/migration/ram.c b/migration/ram.c
> index 5ad7cb3..c71929e 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -61,6 +61,7 @@ static uint64_t bitmap_sync_count;
> #define RAM_SAVE_FLAG_XBZRLE 0x40
> /* 0x80 is reserved in migration.h start with 0x100 next */
> #define RAM_SAVE_FLAG_COMPRESS_PAGE 0x100
> +#define RAM_SAVE_FLAG_MULTIFD_PAGE 0x200
I think a similar reminder from the last iteration of this patch;
I think we're out of bits here - I'm not sure if 0x200 is even
available.
> static uint8_t *ZERO_TARGET_PAGE;
>
> @@ -141,6 +142,7 @@ typedef struct AccountingInfo {
> uint64_t dup_pages;
> uint64_t skipped_pages;
> uint64_t norm_pages;
> + uint64_t multifd_pages;
> uint64_t iterations;
> uint64_t xbzrle_bytes;
> uint64_t xbzrle_pages;
> @@ -211,6 +213,11 @@ uint64_t xbzrle_mig_pages_overflow(void)
> return acct_info.xbzrle_overflows;
> }
>
> +uint64_t multifd_mig_pages_transferred(void)
> +{
> + return acct_info.multifd_pages;
> +}
> +
> /* This is the last block that we have visited serching for dirty pages
> */
> static RAMBlock *last_seen_block;
> @@ -990,6 +997,33 @@ static int ram_save_page(QEMUFile *f, PageSearchStatus
> *pss,
> return pages;
> }
>
> +static int ram_multifd_page(QEMUFile *f, PageSearchStatus *pss,
> + bool last_stage, uint64_t *bytes_transferred)
> +{
> + int pages;
> + uint8_t *p;
> + RAMBlock *block = pss->block;
> + ram_addr_t offset = pss->offset;
> +
> + p = block->host + offset;
> +
> + if (block == last_sent_block) {
> + offset |= RAM_SAVE_FLAG_CONTINUE;
> + }
> + pages = save_zero_page(f, block, offset, p, bytes_transferred);
> + if (pages == -1) {
> + *bytes_transferred +=
> + save_page_header(f, block, offset | RAM_SAVE_FLAG_MULTIFD_PAGE);
> + qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
> + *bytes_transferred += TARGET_PAGE_SIZE;
> + pages = 1;
> + acct_info.norm_pages++;
> + acct_info.multifd_pages++;
> + }
> +
> + return pages;
> +}
> +
> static int do_compress_ram_page(QEMUFile *f, RAMBlock *block,
> ram_addr_t offset)
> {
> @@ -1427,6 +1461,8 @@ static int ram_save_target_page(MigrationState *ms,
> QEMUFile *f,
> res = ram_save_compressed_page(f, pss,
> last_stage,
> bytes_transferred);
> + } else if (migrate_use_multifd()) {
> + res = ram_multifd_page(f, pss, last_stage, bytes_transferred);
I'm curious whether it's best to pick the destination fd at this level or one
level
higher; for example would it be good to keep all the components of a host page
or huge
page together on the same fd? If so then it would be best to pick the fd
at ram_save_host_page level.
Dave
> } else {
> res = ram_save_page(f, pss, last_stage,
> bytes_transferred);
> @@ -2678,6 +2714,10 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> if (!migrate_use_compression()) {
> invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE;
> }
> +
> + if (!migrate_use_multifd()) {
> + invalid_flags |= RAM_SAVE_FLAG_MULTIFD_PAGE;
> + }
> /* This RCU critical section can be very long running.
> * When RCU reclaims in the code start to become numerous,
> * it will be necessary to reduce the granularity of this
> @@ -2705,13 +2745,17 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> if (flags & invalid_flags & RAM_SAVE_FLAG_COMPRESS_PAGE) {
> error_report("Received an unexpected compressed page");
> }
> + if (flags & invalid_flags & RAM_SAVE_FLAG_MULTIFD_PAGE) {
> + error_report("Received an unexpected multifd page");
> + }
>
> ret = -EINVAL;
> break;
> }
>
> if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE |
> - RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) {
> + RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE |
> + RAM_SAVE_FLAG_MULTIFD_PAGE)) {
> RAMBlock *block = ram_block_from_stream(f, flags);
>
> host = host_from_ram_block_offset(block, addr);
> @@ -2786,6 +2830,11 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> break;
> }
> break;
> +
> + case RAM_SAVE_FLAG_MULTIFD_PAGE:
> + qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
> + break;
> +
> case RAM_SAVE_FLAG_EOS:
> /* normal exit */
> break;
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 54232ee..3e93f7f 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -574,6 +574,7 @@
> #
> # @postcopy-requests: The number of page requests received from the
> destination
> # (since 2.7)
> +# @multifd: number of pages sent with multifd (since 2.9)
> #
> # Since: 0.14.0
> ##
> @@ -582,7 +583,8 @@
> 'duplicate': 'int', 'skipped': 'int', 'normal': 'int',
> 'normal-bytes': 'int', 'dirty-pages-rate' : 'int',
> 'mbps' : 'number', 'dirty-sync-count' : 'int',
> - 'postcopy-requests' : 'int' } }
> + 'postcopy-requests' : 'int',
> + 'multifd' : 'int'} }
> ##
> # @XBZRLECacheStats:
> --
> 2.9.3
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
