Daniel P. Berrangé <berrange@xxxxxxxxxx> wrote: > On Mon, Jun 12, 2023 at 09:33:39PM +0200, Juan Quintela wrote: >> Has return zero for more than 10 years. Just mark it deprecated. > > Specifically we introduced the field in 1.5.0 > > commit f1c72795af573b24a7da5eb52375c9aba8a37972 > Author: Peter Lieven <pl@xxxxxxx> > Date: Tue Mar 26 10:58:37 2013 +0100 > > migration: do not sent zero pages in bulk stage > > during bulk stage of ram migration if a page is a > zero page do not send it at all. > the memory at the destination reads as zero anyway. > > even if there is an madvise with QEMU_MADV_DONTNEED > at the target upon receipt of a zero page I have observed > that the target starts swapping if the memory is overcommitted. > it seems that the pages are dropped asynchronously. > > this patch also updates QMP to return the number of > skipped pages in MigrationStats. > > > > but removed its usage in 1.5.3 > > commit 9ef051e5536b6368a1076046ec6c4ec4ac12b5c6 > Author: Peter Lieven <pl@xxxxxxx> > Date: Mon Jun 10 12:14:19 2013 +0200 > > Revert "migration: do not sent zero pages in bulk stage" > > Not sending zero pages breaks migration if a page is zero > at the source but not at the destination. This can e.g. happen > if different BIOS versions are used at source and destination. > It has also been reported that migration on pseries is completely > broken with this patch. > > This effectively reverts commit f1c72795af573b24a7da5eb52375c9aba8a37972. Thanks for the history O:-) >> Signed-off-by: Juan Quintela <quintela@xxxxxxxxxx> >> --- >> docs/about/deprecated.rst | 10 ++++++++++ >> qapi/migration.json | 12 ++++++++++-- >> 2 files changed, 20 insertions(+), 2 deletions(-) > > Reviewed-by: Daniel P. Berrangé <berrange@xxxxxxxxxx> > > >> diff --git a/qapi/migration.json b/qapi/migration.json >> index cb7cd3e578..bcae193733 100644 >> --- a/qapi/migration.json >> +++ b/qapi/migration.json >> @@ -23,7 +23,8 @@ >> # >> # @duplicate: number of duplicate (zero) pages (since 1.2) >> # >> -# @skipped: number of skipped zero pages (since 1.5) >> +# @skipped: number of skipped zero pages. Don't use, only provided for >> +# compatibility (since 1.5) > > I'd say > > @skipped: number of skipped zero pages. Always zero, only provided for > compatibility (since 1.5) Changed. >> # >> # @normal: number of normal pages (since 1.2) >> # >> @@ -62,11 +63,18 @@ >> # between 0 and @dirty-sync-count * @multifd-channels. (since >> # 7.1) >> # >> +# Features: >> +# >> +# @deprecated: Member @skipped has not been used for a long time. > > @deprecated: Member @skipped is always zero since 1.5.3 Changed. Thanks.
