[Qemu-devel] PING: [PATCH v4 0/2] QOM: object_property_add() performance improvement

[Pavel Fedin]

 Ping!!!

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia


> -----Original Message-----
> From: address@hidden [mailto:qemu-devel-
> address@hidden On Behalf Of Pavel Fedin
> Sent: Tuesday, July 14, 2015 12:39 PM
> To: address@hidden
> Cc: Peter Crosthwaite; Andreas Färber
> Subject: [Qemu-devel] [PATCH v4 0/2] QOM: object_property_add() performance 
> improvement
> 
> The function originally behaves very badly when adding properties with "[*]"
> suffix. Normally these are used for numbering IRQ pins. In order to find the
> correct starting number the function started from zero and checked for
> duplicates. This takes incredibly long time with large number of CPUs because
> number of IRQ pins on some architectures (like ARM GICv3) gets multiplied by
> number of CPUs.
> 
> The solution is to add one more property which caches last used index so that
> duplication check is not repeated thousands of times. Every time an array is
> expanded the index is picked up from this cache.
> 
> The modification decreases qemu startup time with 32 CPUs by a factor of 2
> (~10 sec vs ~20 sec).
> 
> Pavel Fedin (2):
>   QOM: Introduce object_property_add_single()
>   QOM: object_property_add() performance improvement
> 
>  qom/object.c | 96 
> +++++++++++++++++++++++++++++++++++++++++++-----------------
>  1 file changed, 69 insertions(+), 27 deletions(-)
> 
> --
> 1.9.5.msysgit.0