From: Mark Rutland Date: Mon, 29 Nov 2021 14:28:43 +0000 (+0000) Subject: arm64: Mark __switch_to() as __sched X-Git-Tag: v6.6.17~8339^2~3^4~6 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=86bcbafcb726b7b11898d2d6269bd665cb27c1b9;p=platform%2Fkernel%2Flinux-rpi.git arm64: Mark __switch_to() as __sched Unlike most architectures (and only in keeping with powerpc), arm64 has a non __sched() function on the path to our cpu_switch_to() assembly function. It is expected that for a blocked task, in_sched_functions() can be used to skip all functions between the raw context switch assembly and the scheduler functions that call into __switch_to(). This is the behaviour expected by stack_trace_consume_entry_nosched(), and the behaviour we'd like to have such that we an simplify arm64's __get_wchan() implementation to use arch_stack_walk(). This patch mark's arm64's __switch_to as __sched. This *will not* change the behaviour of arm64's current __get_wchan() implementation, which always performs an initial unwind step which skips __switch_to(). This *will* change the behaviour of stack_trace_consume_entry_nosched() and stack_trace_save_tsk() to match their expected behaviour on blocked tasks, skipping all scheduler-internal functions including __switch_to(). Other than the above, there should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Madhavan T. Venkataraman Cc: Peter Zijlstra Cc: Will Deacon Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20211129142849.3056714-4-mark.rutland@arm.com Signed-off-by: Catalin Marinas --- diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index aacf2f5..980cad7 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -490,7 +490,8 @@ void update_sctlr_el1(u64 sctlr) /* * Thread switching. */ -__notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, +__notrace_funcgraph __sched +struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next) { struct task_struct *last;