migration: extract ram_load_precopy

After cleanup, it would be clear to audience there are two cases
ram_load:

  * precopy
  * postcopy

And it is not necessary to check postcopy_running on each iteration for
precopy.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Message-Id: <20190725002023.2335-3-richardw.yang@linux.intel.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This commit is contained in:
Wei Yang 2019-07-25 08:20:23 +08:00 committed by Dr. David Alan Gilbert
parent be4a1a1b6f
commit 10da4a3689

View file

@ -4318,40 +4318,26 @@ static void colo_flush_ram_cache(void)
trace_colo_flush_ram_cache_end();
}
static int ram_load(QEMUFile *f, void *opaque, int version_id)
/**
* ram_load_precopy: load pages in precopy case
*
* Returns 0 for success or -errno in case of error
*
* Called in precopy mode by ram_load().
* rcu_read_lock is taken prior to this being called.
*
* @f: QEMUFile where to send the data
*/
static int ram_load_precopy(QEMUFile *f)
{
int flags = 0, ret = 0, invalid_flags = 0;
static uint64_t seq_iter;
int len = 0;
/*
* If system is running in postcopy mode, page inserts to host memory must
* be atomic
*/
bool postcopy_running = postcopy_is_running();
int flags = 0, ret = 0, invalid_flags = 0, len = 0;
/* ADVISE is earlier, it shows the source has the postcopy capability on */
bool postcopy_advised = postcopy_is_advised();
seq_iter++;
if (version_id != 4) {
return -EINVAL;
}
if (!migrate_use_compression()) {
invalid_flags |= RAM_SAVE_FLAG_COMPRESS_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
* critical section.
*/
rcu_read_lock();
if (postcopy_running) {
ret = ram_load_postcopy(f);
}
while (!postcopy_running && !ret && !(flags & RAM_SAVE_FLAG_EOS)) {
while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
ram_addr_t addr, total_ram_bytes;
void *host = NULL;
uint8_t ch;
@ -4502,6 +4488,39 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
}
}
return ret;
}
static int ram_load(QEMUFile *f, void *opaque, int version_id)
{
int ret = 0;
static uint64_t seq_iter;
/*
* If system is running in postcopy mode, page inserts to host memory must
* be atomic
*/
bool postcopy_running = postcopy_is_running();
seq_iter++;
if (version_id != 4) {
return -EINVAL;
}
/*
* 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
* critical section.
*/
rcu_read_lock();
if (postcopy_running) {
ret = ram_load_postcopy(f);
} else {
ret = ram_load_precopy(f);
}
ret |= wait_for_decompress_done();
rcu_read_unlock();
trace_ram_load_complete(ret, seq_iter);