Michael Chapman <m...@very.puzzling.org> wrote:
> This bug manifested itself as a VM that could not be resumed by libvirt
> following a migration:
>
> # virsh resume example
> error: Failed to resume domain example
> error: internal error: cannot parse json {"return":
> {"xbzrle-cache":
> {..., "cache-miss-rate": -nan, ...},
> ...
> }
> }: lexical error: malformed number, a digit is required after the minus
> sign.
>
> This patch also ensures xbzrle_cache_miss_prev and iterations_prev are
> cleared at the start of the migration.
>
> Signed-off-by: Michael Chapman <m...@very.puzzling.org>
Added to queue for 2.4 & stable
Thanks
> ---
> arch_init.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/arch_init.c b/arch_init.c
> index 4c8fcee..ca45c7a 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -520,12 +520,16 @@ static void migration_bitmap_sync_range(ram_addr_t
> start, ram_addr_t length)
> static int64_t start_time;
> static int64_t bytes_xfer_prev;
> static int64_t num_dirty_pages_period;
> +static uint64_t xbzrle_cache_miss_prev;
> +static uint64_t iterations_prev;
>
> static void migration_bitmap_sync_init(void)
> {
> start_time = 0;
> bytes_xfer_prev = 0;
> num_dirty_pages_period = 0;
> + xbzrle_cache_miss_prev = 0;
> + iterations_prev = 0;
> }
>
> /* Called with iothread lock held, to protect ram_list.dirty_memory[] */
> @@ -536,8 +540,6 @@ static void migration_bitmap_sync(void)
> MigrationState *s = migrate_get_current();
> int64_t end_time;
> int64_t bytes_xfer_now;
> - static uint64_t xbzrle_cache_miss_prev;
> - static uint64_t iterations_prev;
>
> bitmap_sync_count++;
>
> @@ -585,7 +587,7 @@ static void migration_bitmap_sync(void)
> mig_throttle_on = false;
> }
> if (migrate_use_xbzrle()) {
> - if (iterations_prev != 0) {
> + if (iterations_prev != acct_info.iterations) {
> acct_info.xbzrle_cache_miss_rate =
> (double)(acct_info.xbzrle_cache_miss -
> xbzrle_cache_miss_prev) /
