To prepare for thread-safety on page accountings, at least below counters
need to be accessed only atomically, they are:
ram_counters.transferred
ram_counters.duplicate
ram_counters.normal
ram_counters.postcopy_bytes
There are a lot of other counters but they won't be accessed outside
migration thread, then they're still safe to be accessed without atomic
ops.
Signed-off-by: Peter Xu <pet...@redhat.com>
---
migration/migration.c | 10 +++++-----
migration/multifd.c | 2 +-
migration/ram.c | 29 +++++++++++++++--------------
3 files changed, 21 insertions(+), 20 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index 07c74a79a2..0eacc0c99b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1048,13 +1048,13 @@ static void populate_ram_info(MigrationInfo *info,
MigrationState *s)
info->has_ram = true;
info->ram = g_malloc0(sizeof(*info->ram));
- info->ram->transferred = ram_counters.transferred;
+ info->ram->transferred = qatomic_read(&ram_counters.transferred);
info->ram->total = ram_bytes_total();
- info->ram->duplicate = ram_counters.duplicate;
+ info->ram->duplicate = qatomic_read(&ram_counters.duplicate);
/* legacy value. It is not used anymore */
info->ram->skipped = 0;
- info->ram->normal = ram_counters.normal;
- info->ram->normal_bytes = ram_counters.normal * page_size;
+ info->ram->normal = qatomic_read(&ram_counters.normal);
+ info->ram->normal_bytes = info->ram->normal * page_size;
info->ram->mbps = s->mbps;
info->ram->dirty_sync_count = ram_counters.dirty_sync_count;
info->ram->dirty_sync_missed_zero_copy =
@@ -1065,7 +1065,7 @@ static void populate_ram_info(MigrationInfo *info,
MigrationState *s)
info->ram->pages_per_second = s->pages_per_second;
info->ram->precopy_bytes = ram_counters.precopy_bytes;
info->ram->downtime_bytes = ram_counters.downtime_bytes;
- info->ram->postcopy_bytes = ram_counters.postcopy_bytes;
+ info->ram->postcopy_bytes = qatomic_read(&ram_counters.postcopy_bytes);
if (migrate_use_xbzrle()) {
info->has_xbzrle_cache = true;
diff --git a/migration/multifd.c b/migration/multifd.c
index 586ddc9d65..460326acd4 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -437,7 +437,7 @@ static int multifd_send_pages(QEMUFile *f)
+ p->packet_len;
qemu_file_acct_rate_limit(f, transferred);
ram_counters.multifd_bytes += transferred;
- ram_counters.transferred += transferred;
+ qatomic_add(&ram_counters.transferred, transferred);
qemu_mutex_unlock(&p->mutex);
qemu_sem_post(&p->sem);
diff --git a/migration/ram.c b/migration/ram.c
index 6e7de6087a..5bd3d76bf0 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -432,11 +432,11 @@ static void ram_transferred_add(uint64_t bytes)
if (runstate_is_running()) {
ram_counters.precopy_bytes += bytes;
} else if (migration_in_postcopy()) {
- ram_counters.postcopy_bytes += bytes;
+ qatomic_add(&ram_counters.postcopy_bytes, bytes);
} else {
ram_counters.downtime_bytes += bytes;
}
- ram_counters.transferred += bytes;
+ qatomic_add(&ram_counters.transferred, bytes);
}
void dirty_sync_missed_zero_copy(void)
@@ -725,7 +725,7 @@ void mig_throttle_counter_reset(void)
rs->time_last_bitmap_sync = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
rs->num_dirty_pages_period = 0;
- rs->bytes_xfer_prev = ram_counters.transferred;
+ rs->bytes_xfer_prev = qatomic_read(&ram_counters.transferred);
}
/**
@@ -1085,8 +1085,9 @@ uint64_t ram_pagesize_summary(void)
uint64_t ram_get_total_transferred_pages(void)
{
- return ram_counters.normal + ram_counters.duplicate +
- compression_counters.pages + xbzrle_counters.pages;
+ return qatomic_read(&ram_counters.normal) +
+ qatomic_read(&ram_counters.duplicate) +
+ compression_counters.pages + xbzrle_counters.pages;
}
static void migration_update_rates(RAMState *rs, int64_t end_time)
@@ -1145,8 +1146,8 @@ static void migration_trigger_throttle(RAMState *rs)
{
MigrationState *s = migrate_get_current();
uint64_t threshold = s->parameters.throttle_trigger_threshold;
-
- uint64_t bytes_xfer_period = ram_counters.transferred -
rs->bytes_xfer_prev;
+ uint64_t bytes_xfer_period =
+ qatomic_read(&ram_counters.transferred) - rs->bytes_xfer_prev;
uint64_t bytes_dirty_period = rs->num_dirty_pages_period *
TARGET_PAGE_SIZE;
uint64_t bytes_dirty_threshold = bytes_xfer_period * threshold / 100;
@@ -1285,7 +1286,7 @@ static int save_zero_page(RAMState *rs, RAMBlock *block,
ram_addr_t offset)
int len = save_zero_page_to_file(rs, rs->f, block, offset);
if (len) {
- ram_counters.duplicate++;
+ qatomic_inc(&ram_counters.duplicate);
ram_transferred_add(len);
return 1;
}
@@ -1322,9 +1323,9 @@ static bool control_save_page(RAMState *rs, RAMBlock
*block, ram_addr_t offset,
}
if (bytes_xmit > 0) {
- ram_counters.normal++;
+ qatomic_inc(&ram_counters.normal);
} else if (bytes_xmit == 0) {
- ram_counters.duplicate++;
+ qatomic_inc(&ram_counters.duplicate);
}
return true;
@@ -1354,7 +1355,7 @@ static int save_normal_page(RAMState *rs, RAMBlock
*block, ram_addr_t offset,
qemu_put_buffer(rs->f, buf, TARGET_PAGE_SIZE);
}
ram_transferred_add(TARGET_PAGE_SIZE);
- ram_counters.normal++;
+ qatomic_inc(&ram_counters.normal);
return 1;
}
@@ -1448,7 +1449,7 @@ update_compress_thread_counts(const CompressParam *param,
int bytes_xmit)
ram_transferred_add(bytes_xmit);
if (param->zero_page) {
- ram_counters.duplicate++;
+ qatomic_inc(&ram_counters.duplicate);
return;
}
@@ -2620,9 +2621,9 @@ void acct_update_position(QEMUFile *f, size_t size, bool
zero)
uint64_t pages = size / TARGET_PAGE_SIZE;
if (zero) {
- ram_counters.duplicate += pages;
+ qatomic_add(&ram_counters.duplicate, pages);
} else {
- ram_counters.normal += pages;
+ qatomic_add(&ram_counters.normal, pages);
ram_transferred_add(size);
qemu_file_credit_transfer(f, size);
}
--
2.32.0
