Leonardo Brás <leob...@redhat.com> wrote:
> On Mon, 2023-05-15 at 21:57 +0200, Juan Quintela wrote:
>> In the past, we had to put the in the main thread all the operations
>> related with sizes due to qemu_file not beeing thread safe. As now
>> all counters are atomic, we can update the counters just after the
>> do the write. As an aditional bonus, we are able to use the right
>> value for the compression methods. Right now we were assuming that
>> there were no compression at all.
>>
>> Signed-off-by: Juan Quintela <quint...@redhat.com>
>> ---
>> migration/multifd.c | 13 ++++++++-----
>> 1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/migration/multifd.c b/migration/multifd.c
>> index aabf9b6d98..0bf5958a9c 100644
>> --- a/migration/multifd.c
>> +++ b/migration/multifd.c
>> @@ -175,6 +175,7 @@ void multifd_register_ops(int method, MultiFDMethods
>> *ops)
>> static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
>> {
>> MultiFDInit_t msg = {};
>> + size_t size = sizeof(msg);
>> int ret;
>>
>> msg.magic = cpu_to_be32(MULTIFD_MAGIC);
>> @@ -182,10 +183,12 @@ static int
>> multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
>> msg.id = p->id;
>> memcpy(msg.uuid, &qemu_uuid.data, sizeof(msg.uuid));
>>
>> - ret = qio_channel_write_all(p->c, (char *)&msg, sizeof(msg), errp);
>> + ret = qio_channel_write_all(p->c, (char *)&msg, size, errp);
>> if (ret != 0) {
>> return -1;
>> }
>> + stat64_add(&mig_stats.multifd_bytes, size);
>> + stat64_add(&mig_stats.transferred, size);
>> return 0;
>> }
>
> Humm, those are atomic ops, right?
>
> You think we could have 'multifd_bytes' and 'transferred' in the same
> cacheline,
> to avoid 2 cacheline bounces?
Don't matter on next series.
mig_stats.transferred is dropped.
And transferred becomes:
qemu_file_transferred + multifd_bytes + rdma_bytes.
So everytime that we do a write, we only update one counter.
> Well, it's unrelated to this patchset, so:
>
> Reviewed-by: Leonardo Bras <leob...@redhat.com>
