[libvirt] Re: [PATCH 7/6] Only probe qemu for machine types when binary changes
Cole Robinson
crobinso at redhat.com
Fri Jul 24 15:08:20 UTC 2009
Mark McLoughlin wrote:
> By probing for qemu machine types, we increased the time of a
> GetCapabilities call from 100us to a whopping 60ms.
>
> This patch takes the approach of only probing for machine types
> when the mtime of the emulator binary changed since the last time
> the capabilities were generated.
>
Good idea!
> This brings the time of the call back to what it was for the most
> common case.
>
> * src/capabilities.h: cache the emulator binary mtime
>
> * src/qemu_conf.c: add qemudGetOldMachines() to copy the machine
> types from the old caps struct if the mtime for the binary hasn't
> changed
>
> * src/qemu_conf.h, src/qemu_driver.c: pass the old caps pointer to
> qemudCapsInit()
> ---
> src/capabilities.h | 1 +
> src/qemu_conf.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++---
> src/qemu_conf.h | 2 +-
> src/qemu_driver.c | 4 +-
> 4 files changed, 95 insertions(+), 9 deletions(-)
>
...
ACK, patch looks good to me.
- Cole
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