Re: [PATCH v0] add nano semaphore in kernel

Hillf Danton
2010-12-26T07:04:24Z

On Sun, Dec 26, 2010 at 2:46 PM, Rakib Mullick <rakib.mullick@gmail.com> wrote:
> On Sun, Dec 26, 2010 at 11:13 AM, Hillf Danton <dhillf@gmail.com> wrote:
>> Based upon high resolution timer and idea borrowed from semaphore,
>> nano semaphore is created.
>>
>> Nano semaphore provides finer time resolution depending on system
>> configuration and capabilities.
>>
>> Nano semaphore is not to replace semaphore, but used in application
>> environments where nano seconds are required.
>>
>> Three methods, nano_semaphore_try_down, nano_semaphore_down and
>> nano_semaphore_up are implemented in a header file, and there is no
>> corresponding C file since nano semaphore is not complex.
>>
>
> Above description tells how its done, what it is but its not clear why
> we should use it. Can I know why should we use it or its benefits?
>

The outstanding benefit looks that nano semaphore could be used in
cases where callers want to wait not only more than one jiffy, but far
less than one jiffy also.

thanks
Hillf

>
> thanks,
> rakib