* Alexey Kardashevskiy (a...@ozlabs.ru) wrote: > This was inspired by https://bugzilla.redhat.com/show_bug.cgi?id=1481593 > > What happens ithere is that every virtio block device creates 2 address > spaces - for modern config space (called "virtio-pci-cfg-as") and > for busmaster (common pci thing, called after the device name, > in my case "virtio-blk-pci"). > > Each address_space_init() updates topology for every address space. > Every topology update (address_space_update_topology()) creates a new > dispatch tree - AddressSpaceDispatch with nodes (1KB) and > sections (48KB) and destroys the old one. > > However the dispatch destructor is postponed via RCU which does not > get a chance to execute until the machine is initialized but before > we get there, memory is not returned to the pool, and this is a lot > of memory which grows n^2. > > These patches are trying to address the memory use and boot time > issues but tbh only the first one provides visible outcome.
Do you have a feel for how much memory is saved? Dave > There are still things to polish and double check the use of RCU, > I'd like to get any feedback before proceeding - is this going > the right way or way too ugly? > > > This is based on sha1 > 1ab5eb4efb Peter Maydell "Update version for v2.10.0 release". > > Please comment. Thanks. > > > > Alexey Kardashevskiy (4): > memory: Postpone flatview and dispatch tree building till all devices > are added > memory: Prepare for shared flat views > memory: Share flat views and dispatch trees between address spaces > memory: Add flat views to HMP "info mtree" > > include/exec/memory-internal.h | 6 +- > include/exec/memory.h | 93 +++++++++---- > exec.c | 242 +++++++++++++++++++-------------- > hw/alpha/typhoon.c | 2 +- > hw/dma/rc4030.c | 4 +- > hw/i386/amd_iommu.c | 2 +- > hw/i386/intel_iommu.c | 9 +- > hw/intc/openpic_kvm.c | 2 +- > hw/pci-host/apb.c | 2 +- > hw/pci/pci.c | 3 +- > hw/ppc/spapr_iommu.c | 4 +- > hw/s390x/s390-pci-bus.c | 2 +- > hw/vfio/common.c | 6 +- > hw/virtio/vhost.c | 6 +- > memory.c | 299 > +++++++++++++++++++++++++++-------------- > monitor.c | 3 +- > vl.c | 4 + > hmp-commands-info.hx | 7 +- > 18 files changed, 448 insertions(+), 248 deletions(-) > > -- > 2.11.0 > > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
