On 06.03.22 13:46, Alexandre Derumier wrote: > Hi, > > Currently, if a guest vm allocate a memory page, and freed it later in the > guest, > the memory is not freed on the host side. > > Balloon device have a new option since qemu 5.1 "free-page-reporting" (and > need host kernel 5.7) > > https://events19.linuxfoundation.org/wp-content/uploads/2017/12/KVMForum2018.pdf > https://lwn.net/Articles/759413/ > > This is working like the discard option for disk, memory is freed async by > the host when vm is freeing it. > > I'm running it production since 1 month without any problem. With a lot of > vms and spiky workload, the memory > freed is really huge. > > Here an example of a host with 650GB+200GB ksm going down to 250GB memory > https://mutulin1.odiso.net/ballon-size.png > (around 400vms with 2GB max memory, previously always allocated) > > > This patch enabled it by default force machine version >= 6.2. > > > changelogv2: > > - enabled it only for machine version > 6.2 > - add test > > Alexandre Derumier (2): > enable balloon free-page-reporting > add test for virtio-balloon free-page-reporting=on. (qemu 6.2) > > PVE/QemuServer.pm | 4 ++- > test/cfg2cmd/q35-simple-7.0.conf.cmd | 2 +- > .../simple-balloon-free-page-reporting.conf | 15 +++++++++ > ...imple-balloon-free-page-reporting.conf.cmd | 33 +++++++++++++++++++ > 4 files changed, 52 insertions(+), 2 deletions(-) > create mode 100644 test/cfg2cmd/simple-balloon-free-page-reporting.conf > create mode 100644 test/cfg2cmd/simple-balloon-free-page-reporting.conf.cmd >
applied series, thanks! Had to fixup the existing un-versioned tests though. _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
