[PATCH 1/1] arm/syscalls: mark syscall invocation as

[Can Peng]

Hello,

>> The invoke_syscall() function is overwhelmingly called for
>> valid system call entries. Annotate the main path with likely()
>> to help the compiler generate better branch prediction hints,
>> reducing CPU pipeline stalls due to mispredictions.
>> 
>> This is a micro-optimization targeting syscall-heavy workloads.
>
>Does it actually make a measurable difference?

This change implements a micro-optimization. Benchmark results
from the Kunpeng 920 machine are as follows:

before:
- lat_syscall result 
write call      0.2332  0.2337  0.2341
read call       0.2501  0.2493  0.2506

after:
- lat_syscall result
write call      0.2301  0.2316  0.2307
read call       0.2492  0.2498  0.2491


Best regards,
Can Peng