diff options
| author | Michael Chapman <mike@very.puzzling.org> | 2015-04-15 13:59:14 +1000 |
|---|---|---|
| committer | Juan Quintela <quintela@redhat.com> | 2015-05-07 18:31:54 +0200 |
| commit | 27ff42e29a1d12e9d9dbc473bbca36a50baf278b (patch) | |
| tree | 4573c773995ee4538fd0caa288d98e8dbce0d4f5 | |
| parent | 50e9a629c6c92e73260cd3d7c2e3f5bfd84e47e2 (diff) | |
migration: avoid divide by zero in xbzrle cache miss rate
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 <mike@very.puzzling.org>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
| -rw-r--r-- | arch_init.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch_init.c b/arch_init.c index 539011d2c6..bbf0031019 100644 --- a/arch_init.c +++ b/arch_init.c @@ -663,12 +663,16 @@ 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[] */ @@ -679,8 +683,6 @@ 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++; @@ -728,7 +730,7 @@ 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) / |