powerpc/syscall: Avoid atomic test_and_clear_thread_flag on fast path

In system_call_exception(), test_and_clear_thread_flag(TIF_SYSCALL_RET)
performs an atomic bit test-and-clear operation on every system call entry.
This introduces an unnecessary performance regression on the syscall fast
path.

Combine the TIF_SYSCALL_RET check with the unlikely error condition from
syscall_enter_from_user_mode_randomize_stack() using non-atomic
test_thread_flag(). If the flag is set or entry failed, only then clear the
flag via clear_thread_flag() and return the error value.

Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260929071744.2965058-1-mkchauras@gmail.com

0 files changed, 0 insertions, 0 deletions