Re: [Qemu-devel] [PATCH 03/15] qom: introduce reclaimer to release obj

[liu ping fan]

On Wed, Aug 8, 2012 at 5:15 PM, Avi Kivity <address@hidden> wrote:
> On 08/08/2012 12:07 PM, Paolo Bonzini wrote:
>> Il 08/08/2012 11:05, Avi Kivity ha scritto:
>>>> > From: Liu Ping Fan <address@hidden>
>>>> >
>>>> > Collect unused object and release them at caller demand.
>>>> >
>>> Please explain the motivation for this patch.
>>
>> It's poor man RCU, I think?
>
> I thought that it was to defer destructors (finalizers) to a more
> suitable context.  But why is the unref context unsuitable?
>
Yes, it is to defer destructors.
See 0009-memory-prepare-flatview-and-radix-tree-for-rcu-style.patch
When MemoryRegion is _del_subregion from mem in updater, it may be
still in use by reader -- radix or flatview, so defer its destructors
to the reclaimer --phys_map_release(PhysMap *map)
If we have rcu, it could be elegant to do this.

I think, I should write the commit comment here too,  not until the
followed patch.

Regards, pingfan
> I don't see how it relates to RCU, where is the C and the U?
>
> Anyway the list eagerly awaits the explanation.
>
> --
> error compiling committee.c: too many arguments to function