Any comments? Liang > -----Original Message----- > From: Li, Liang Z > Sent: Monday, June 13, 2016 5:47 PM > To: kvm@xxxxxxxxxxxxxxx > Cc: virtio-dev@xxxxxxxxxxxxxxxxxxxx; qemu-devel@xxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; mst@xxxxxxxxxx; Li, Liang Z > Subject: [PATCH 0/6] Fast balloon & fast live migration > > The implementation of the current virtio-balloon is not very efficient, bellow > is test result of time spends on inflating the balloon to 3GB of a 4GB idle > guest: > > a. allocating pages (6.5%, 103ms) > b. sending PFNs to host (68.3%, 787ms) > c. address translation (6.1%, 96ms) > d. madvise (19%, 300ms) > > It takes about 1577ms for the whole inflating process to complete. > The test shows that the bottle neck is the stage b and stage d. > > If using a bitmap to send the page info instead of the PFNs, we can reduce > the overhead in stage b quite a lot. Furthermore, it's possible to do the > address translation and the madvise with a bulk of pages, instead of the > current page per page way, so the overhead of stage c and stage d can also > be reduced a lot. > > In addition, we can speed up live migration by skipping process guest's free > pages. > > Patch 1 and patch 2 are the kernel side implementation which are intended > to speed up the inflating & deflating process by adding a new feature to the > virtio-balloon device. And now, inflating the balloon to 3GB of a 4GB idle > guest only takes 200ms, it's about 8 times as fast as before. > > > Patch 3 and patch 4 add the cache drop support, now hypervisor can request > the guest to drop it's cache. It's useful before inflating the virtio-balloon and > before starting live migration. > > Patch 5 and patch 6 save guest's free page information into a page bitmap > and send the bitmap to host through balloon's virt queue. > > Liang Li (6): > virtio-balloon: rework deflate to add page to a list > virtio-balloon: speed up inflate/deflate process > mm:split the drop cache operation into a function > virtio-balloon: add drop cache support > mm: add the related functions to get free page info > virtio-balloon: tell host vm's free page info > > drivers/virtio/virtio_balloon.c | 321 > +++++++++++++++++++++++++++++++----- > fs/drop_caches.c | 22 ++- > include/linux/mm.h | 1 + > include/uapi/linux/virtio_balloon.h | 2 + > mm/page_alloc.c | 40 +++++ > 5 files changed, 339 insertions(+), 47 deletions(-) > > -- > 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
