On 2014/2/28 18:16, Dr. David Alan Gilbert wrote:
> * Gonglei (Arei) (arei.gong...@huawei.com) wrote:
>> It is inaccuracy and complex that using the transfer speed of
>> migration thread to determine whether the convergence migration.
>> The dirty page may be compressed by XBZRLE or ZERO_PAGE.The counter
>> of updating dirty bitmap will be increasing continuously if the
>> migration can't convergence.
>>
>> Signed-off-by: ChenLiang <chenlian...@huawei.com>
>> Signed-off-by: Gonglei <arei.gong...@huawei.com>
>> ---
>> arch_init.c | 26 +++-----------------------
>> 1 file changed, 3 insertions(+), 23 deletions(-)
>>
>> diff --git a/arch_init.c b/arch_init.c
>> index fc71331..2211e0b 100644
>> --- a/arch_init.c
>> +++ b/arch_init.c
>> @@ -107,7 +107,6 @@ int graphic_depth = 32;
>>
>> const uint32_t arch_type = QEMU_ARCH;
>> static bool mig_throttle_on;
>> -static int dirty_rate_high_cnt;
>> static void check_guest_throttling(void);
>>
>> static uint64_t bitmap_sync_cnt;
>> @@ -464,17 +463,11 @@ static void migration_bitmap_sync(void)
>> uint64_t num_dirty_pages_init = migration_dirty_pages;
>> MigrationState *s = migrate_get_current();
>> static int64_t start_time;
>> - static int64_t bytes_xfer_prev;
>> static int64_t num_dirty_pages_period;
>> int64_t end_time;
>> - int64_t bytes_xfer_now;
>>
>> increase_bitmap_sync_cnt();
>>
>> - if (!bytes_xfer_prev) {
>> - bytes_xfer_prev = ram_bytes_transferred();
>> - }
>> -
>> if (!start_time) {
>> start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
>> }
>> @@ -493,21 +486,9 @@ static void migration_bitmap_sync(void)
>> /* more than 1 second = 1000 millisecons */
>> if (end_time > start_time + 1000) {
>> if (migrate_auto_converge()) {
>> - /* The following detection logic can be refined later. For now:
>> - Check to see if the dirtied bytes is 50% more than the
>> approx.
>> - amount of bytes that just got transferred since the last
>> time we
>> - were in this routine. If that happens >N times (for now N==4)
>> - we turn on the throttle down logic */
>> - bytes_xfer_now = ram_bytes_transferred();
>> - if (s->dirty_pages_rate &&
>> - (num_dirty_pages_period * TARGET_PAGE_SIZE >
>> - (bytes_xfer_now - bytes_xfer_prev)/2) &&
>> - (dirty_rate_high_cnt++ > 4)) {
>> - trace_migration_throttle();
>> - mig_throttle_on = true;
>> - dirty_rate_high_cnt = 0;
>> - }
>> - bytes_xfer_prev = bytes_xfer_now;
>> + if (get_bitmap_sync_cnt() > 15) {
>> + mig_throttle_on = true;
>> + }
>
> That is a lot simpler, and I suspect as good - again I'd
> move that magic '15' to a constant somewhere.
>
Thanks, Check it.
> What have you tested this on - have you tested with really big RAM VMs?
> What's it's behaviour like with rate-limiting?
>
> Dave
Yeah, We have tested it using 25G memory VM as the first mail said.
>>
> --
> Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
Best regards,
-Gonglei
