Commit da9e5c04 authored by Can Peng's avatar Can Peng Committed by Will Deacon
Browse files

arm/syscalls: mark syscall invocation as likely in invoke_syscall 

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 [1].

Link: https://lore.kernel.org/r/20250922121730.986761-1-pengcan@kylinos.cn

 [1]
Signed-off-by: default avatarCan Peng <pengcan@kylinos.cn>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent b3cf0785

arch/arm64/kernel/syscall.c

+1 −1
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno, 


	add_random_kstack_offset();



	if (scno < sc_nr) {

	if (likely(scno < sc_nr)) {

		syscall_fn_t syscall_fn;

		syscall_fn = syscall_table[array_index_nospec(scno, sc_nr)];

		ret = __invoke_syscall(regs, syscall_fn);