[SLOF] [PATCH 3/4] fbuffer: Implement MRMOVE as an accelerated primitive

Thomas Huth thuth at redhat.com
Tue Aug 4 01:53:04 AEST 2015

On 03/08/15 12:37, Nikunj A Dadhania wrote:
> Thomas Huth <thuth at redhat.com> writes:
>> The character drawing function fb8-draw-character uses "mrmove"
>> (which moves main memory contents to IO memory) to copy the data
>> of the character from main memory to the frame buffer. However,
>> the current implementation of "mrmove"  performs quite badly on
>> board-qemu since it triggers a hypercall for each memory access
>> (e.g. for each 8 bytes that are transfered).
>> But since the KVMPPC_H_LOGICAL_MEMOP hypercall can transfer bigger
>> regions at once, we can accelerate the character drawing quite a
>> bit by simply mapping the "mrmove" to the same macro that is
>> already used for the "rmove". For keeping board-js2x in sync,
>> this patch also transforms the "mrmove" for js2x into primitives.
>> Signed-off-by: Thomas Huth <thuth at redhat.com>
> I dont have a js2x handy, did you test this on js2x?

No, sorry, unfortunately, I also was not able to test this on js2x yet.
I still have a YDL PowerStation somewhere in a corner of my flat, but
it's currently not set up ... will do that one day when I got enough
spare time again, but that won't happen within the next few weeks (KVM
forum's ahead!). So if there are problems, I'll fix them up as soon as I
got the PowerStation running again (and I guess there might be other
problems, too, since board-js2x hardly got any testing within the last
months/years, I think).


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