On Wed, 13 Jan 2021 00:00:56 +0100 Sebastian Andrzej Siewior <bige...@linutronix.de> wrote:
> Use in_serving_softirq() macro which works on PREEMPT_RT. On !PREEMPT_RT > the compiler (gcc-10 / clang-11) is smart enough to optimize the > in_serving_softirq() related read of the preemption counter away. > The only difference I noticed by using in_serving_softirq() on > !PREEMPT_RT is that gcc-10 implemented tracing_gen_ctx_flags() as > reading FLAG, jmp _tracing_gen_ctx_flags(). Without in_serving_softirq() > it inlined _tracing_gen_ctx_flags() into tracing_gen_ctx_flags(). If we inline it normally (as described in my first patch reply), there may be no difference. -- Steve
