Oh my God! That sounds terrible! Does this change actually do
/anything /positive.
Duplicating the internal implementation of Linux is /NOT /positive. It
is irrelevant.
Adopting GNU/Linux interfaces as a functional specification made since.
But duplicating the ibnternal implementation of Linux is the dumbest
thing I have ever heard.
Losing any real time performance is /catastrophic /for an RTOS.
Significantly increasing code size is /catastrophic /for an embedded OS.
This is a very bad change that should never come into the repository.
My recommendation is that you quietly close the PR without merge and be
done with it.
The solution that we want is:
* One that conforms to interface standards
* Results in the smallest footprint possible
* Gives the best real time behavior possible.
Nothing else should be accepted.
On 4/6/2023 5:27 AM, zyfeier wrote:
Hi, All:
The main purpose of this PR is to separate mutex and semaphore and to improve
the performance of mutex.
Regarding the issues mentioned in the email , here is a summary:
1. The number of system calls will increase.
After separating mutex and semaphore, futex support will be added in the next
step, which can reduce the number of system calls.
2. Code size will increase.
The increase in code size is a drawback of this modification, but the mutex
performance has improved by 200 cycles. I think code size can be considered as
a potential optimization item in the future.
3. Removing semaphore priority inheritance will affect real-time performance.
Semaphore priority inheritance will be retained. After separating mutex and
semaphore, they will have their own priority inheritance handling. Choose which
one to enable according to your needs.
Thanks.
Yuan.
