Hi, Greg
2016-11-15 18:18 GMT+08:00 Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>:
> On Tue, Nov 15, 2016 at 05:55:39PM +0800, Ganesh Mahendran wrote:
>> VM_IOREMAP is used to access hardware through a mechanism called
>> I/O mapped memory. Android binder is a IPC machanism which will
>> not access I/O memory.
>>
>> Also VM_IOREMAP has alignment requiement which may not needed in
>> binder.
>> __get_vm_area_node()
>> {
>> ...
>> if (flags & VM_IOREMAP)
>> align = 1ul << clamp_t(int, fls_long(size),
>> PAGE_SHIFT, IOREMAP_MAX_ORDER);
>> ...
>> }
>>
>> This patch use VM_ALLOC to get vm area.
>>
>> Below is the throughput test result:
>>
>> # ./binderThroughputTest -w 100
>> I run this command 10 times:
>> before after
>> average iterations per sec: 11199.9 11886.9
>>
>> No performance regression found throgh binder test.
>>
>> Signed-off-by: Ganesh Mahendran <opensource.ganesh@xxxxxxxxx>
>> ---
>> drivers/android/binder.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> What changed from v1?
Sorry for missing the change information.
In V2, I run the binder test. And there is no side effect with this
patch.
>
> Always list that below the --- line.
Thanks for reminder.
>
> thanks,
>
> greg k-h
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