[libvirt] [PATCH v2 0/3] Add caching of QEMU probed capabilities

A followup to https://www.redhat.com/archives/libvir-list/2014-March/msg00297.html Probing capabilities takes 200-300ms per binary and we have as many as 26 binaries. This noticably slows down libvirtd startup. It does not look like performance of probing QEMU can be improved, so this series introduces caching of the capabilities information. So the first time libvirtd starts it'll be slow, but thereafter it is fast. The cache is invalidated any time the QEMU binary timestamp changes or the libvirtd binary or driver module timestamp changes. In v2: - Store timestamps in XML file instead of non-portable utimes() - Use ctime instead of mtime since the latter can be faked by package managers to go backwards in time. Daniel P. Berrange (3): Add helper APIs to track if libvirtd or loadable modules have changed Change QEMU capabilities cache to check ctime instead of mtime Cache result of QEMU capabilities extraction daemon/libvirtd.c | 2 + src/driver.c | 2 + src/libvirt_private.syms | 2 + src/qemu/qemu_capabilities.c | 442 +++++++++++++++++++++++++++++++++++++++++-- src/qemu/qemu_capabilities.h | 2 + src/qemu/qemu_driver.c | 1 + src/util/virutil.c | 23 +++ src/util/virutil.h | 4 + 8 files changed, 467 insertions(+), 11 deletions(-) -- 1.8.5.3