search for: iz_zero_range

...ately. Couldn't agree more. There are three stages in this optimization: 1) choosing which pages to skip 2) communicating them from guest to host 3) skip transferring uninteresting pages to the remote side on migration For (3) there seems to be a low-hanging fruit to amend migration/ram.c:iz_zero_range() to consult /proc/self/pagemap. This would work for guest RAM that hasn't been touched yet or which has been ballooned out. For (1) I've been trying to make a point that skipping clean pages is much more likely to result in noticable benefit than free pages only. As for (2), we do seem...

...ately. Couldn't agree more. There are three stages in this optimization: 1) choosing which pages to skip 2) communicating them from guest to host 3) skip transferring uninteresting pages to the remote side on migration For (3) there seems to be a low-hanging fruit to amend migration/ram.c:iz_zero_range() to consult /proc/self/pagemap. This would work for guest RAM that hasn't been touched yet or which has been ballooned out. For (1) I've been trying to make a point that skipping clean pages is much more likely to result in noticable benefit than free pages only. As for (2), we do seem...

...> > 1) choosing which pages to skip > > > > 2) communicating them from guest to host > > > > 3) skip transferring uninteresting pages to the remote side on migration > > > > For (3) there seems to be a low-hanging fruit to amend > > migration/ram.c:iz_zero_range() to consult /proc/self/pagemap. This would > > work for guest RAM that hasn't been touched yet or which has been > > ballooned out. > > > > For (1) I've been trying to make a point that skipping clean pages is much > > more likely to result in noticable bene...

...> > 1) choosing which pages to skip > > > > 2) communicating them from guest to host > > > > 3) skip transferring uninteresting pages to the remote side on migration > > > > For (3) there seems to be a low-hanging fruit to amend > > migration/ram.c:iz_zero_range() to consult /proc/self/pagemap. This would > > work for guest RAM that hasn't been touched yet or which has been > > ballooned out. > > > > For (1) I've been trying to make a point that skipping clean pages is much > > more likely to result in noticable bene...

...hree stages in this optimization: > > 1) choosing which pages to skip > > 2) communicating them from guest to host > > 3) skip transferring uninteresting pages to the remote side on migration > > For (3) there seems to be a low-hanging fruit to amend > migration/ram.c:iz_zero_range() to consult /proc/self/pagemap. This would > work for guest RAM that hasn't been touched yet or which has been > ballooned out. > > For (1) I've been trying to make a point that skipping clean pages is much > more likely to result in noticable benefit than free pages only....

...> > > > > 2) communicating them from guest to host > > > > > > 3) skip transferring uninteresting pages to the remote side on > > > migration > > > > > > For (3) there seems to be a low-hanging fruit to amend > > > migration/ram.c:iz_zero_range() to consult /proc/self/pagemap. This > > > would work for guest RAM that hasn't been touched yet or which has > > > been ballooned out. > > > > > > For (1) I've been trying to make a point that skipping clean pages > > > is much more likely to...

...hree stages in this optimization: > > 1) choosing which pages to skip > > 2) communicating them from guest to host > > 3) skip transferring uninteresting pages to the remote side on migration > > For (3) there seems to be a low-hanging fruit to amend > migration/ram.c:iz_zero_range() to consult /proc/self/pagemap. This > would work for guest RAM that hasn't been touched yet or which has been > ballooned out. > > For (1) I've been trying to make a point that skipping clean pages is > much more likely to result in noticable benefit than free pages only....

> > No. And it's exactly what I mean. The ballooned memory is still > > processed during live migration without skipping. The live migration code is > in migration/ram.c. > > So if guest acknowledged VIRTIO_BALLOON_F_MUST_TELL_HOST, we can > teach qemu to skip these pages. > Want to write a patch to do this? > Yes, we really can teach qemu to skip these pages

> > No. And it's exactly what I mean. The ballooned memory is still > > processed during live migration without skipping. The live migration code is > in migration/ram.c. > > So if guest acknowledged VIRTIO_BALLOON_F_MUST_TELL_HOST, we can > teach qemu to skip these pages. > Want to write a patch to do this? > Yes, we really can teach qemu to skip these pages