xemu-project/xemu
1
0
Fork 0
mirror of https://github.com/xemu-project/xemu.git synced 2024-11-24 03:59:52 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

migration: keep bytes_xfer_prev init'd to zero

Browse Source 
The first time migration_bitmap_sync() is called, bytes_xfer_prev is set
to ram_state.bytes_transferred which is, at this point, zero. The next
time migration_bitmap_sync() is called, an iteration has happened and
bytes_xfer_prev is set to 'x' bytes. Most likely, more than one second
has passed, so the auto converge logic will be triggered and
bytes_xfer_now will also be set to 'x' bytes.

This condition is currently masked by dirty_rate_high_cnt, which will
wait for a few iterations before throttling. It would otherwise always
assume zero bytes have been copied and therefore throttle the guest
(possibly) prematurely.

Given bytes_xfer_prev is only used by the auto convergence logic, it
makes sense to only set its value after a check has been made against
bytes_xfer_now.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
Felipe Franciosi 2017-05-24 17:10:00 +01:00 committed by Juan Quintela
parent 20a519a05a
commit 9884db2814
1 changed files with 0 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
migration/ram.c
View File

@ -673,10 +673,6 @@ static void migration_bitmap_sync(RAMState *rs)
rs->bitmap_sync_count++;
if (!rs->bytes_xfer_prev) {
rs->bytes_xfer_prev = ram_bytes_transferred();
}
if (!rs->time_last_bitmap_sync) {
rs->time_last_bitmap_sync = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
}