Hello Peter,
On Thu, Jul 7, 2022 at 2:54 PM Peter Xu <pet...@redhat.com> wrote:
>
> On Mon, Jul 04, 2022 at 05:23:14PM -0300, Leonardo Bras wrote:
> > Signed-off-by: Leonardo Bras <leob...@redhat.com>
> > ---
> > qapi/migration.json | 7 ++++++-
> > migration/migration.c | 2 ++
> > monitor/hmp-cmds.c | 4 ++++
> > 3 files changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/qapi/migration.json b/qapi/migration.json
> > index 7102e474a6..fed08b9b88 100644
> > --- a/qapi/migration.json
> > +++ b/qapi/migration.json
> > @@ -55,6 +55,10 @@
> > # @postcopy-bytes: The number of bytes sent during the post-copy phase
> > # (since 7.0).
> > #
> > +# @dirty-sync-missed-zero-copy: Number of times dirty RAM synchronization
> > could
> > +# not avoid copying zero pages. This is
> > between 0
>
> Avoid copying zero pages? Isn't this for counting MSG_ZEROCOPY fallbacks?
Yes, sorry, I think I got confused at some point between some cuts & pastes.
It should be "not avoid copying dirty pages." I will fix that on a V4.
>
> > +# and @dirty-sync-count * @multifd-channels.
>
> I'd not name it as "dirty-sync-*" because fundamentally the accounting is
> not doing like that (more in latter patch).
Ok, I will take a look & answer there.
> I also think we should squash
> patch 2/3 as patch 3 only started to provide meaningful values.
IIRC Previously in zero-copy-send implementation, I was asked to keep the
property/capability in a separated patch in order to make it easier to review.
So I thought it would be helpful now.
>
> > +# (since 7.1)
> > # Since: 0.14
> > ##
> > { 'struct': 'MigrationStats',
> > @@ -65,7 +69,8 @@
> > 'postcopy-requests' : 'int', 'page-size' : 'int',
> > 'multifd-bytes' : 'uint64', 'pages-per-second' : 'uint64',
> > 'precopy-bytes' : 'uint64', 'downtime-bytes' : 'uint64',
> > - 'postcopy-bytes' : 'uint64' } }
> > + 'postcopy-bytes' : 'uint64',
> > + 'dirty-sync-missed-zero-copy' : 'uint64' } }
> >
> > ##
> > # @XBZRLECacheStats:
> > diff --git a/migration/migration.c b/migration/migration.c
> > index 78f5057373..048f7f8bdb 100644
> > --- a/migration/migration.c
> > +++ b/migration/migration.c
> > @@ -1027,6 +1027,8 @@ static void populate_ram_info(MigrationInfo *info,
> > MigrationState *s)
> > info->ram->normal_bytes = ram_counters.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 =
> > + ram_counters.dirty_sync_missed_zero_copy;
> > info->ram->postcopy_requests = ram_counters.postcopy_requests;
> > info->ram->page_size = page_size;
> > info->ram->multifd_bytes = ram_counters.multifd_bytes;
> > diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> > index ca98df0495..5f3be9e405 100644
> > --- a/monitor/hmp-cmds.c
> > +++ b/monitor/hmp-cmds.c
> > @@ -307,6 +307,10 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
> > monitor_printf(mon, "postcopy ram: %" PRIu64 " kbytes\n",
> > info->ram->postcopy_bytes >> 10);
> > }
> > + if (info->ram->dirty_sync_missed_zero_copy) {
> > + monitor_printf(mon, "missed zero-copy on: %" PRIu64 "
> > iterations\n",
> > + info->ram->dirty_sync_missed_zero_copy);
>
> I suggest we don't call it "iterations" because it's not the generic mean
> of iterations.
Yeah, I thought that too, but I could not think on anything better.
What do you suggest instead?
Best regards,
Leo
>
> > + }
> > }
> >
> > if (info->has_disk) {
> > --
> > 2.36.1
> >
>
> --
> Peter Xu
>
