Re: [PATCH 1/2] tracepoints: Add helper to test if tracepoint is enabled in a header

From: Steven Rostedt
Date: Thu Sep 24 2020 - 15:40:16 EST


On Thu, 24 Sep 2020 15:35:17 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> > I'm ok with tracepoint_enabled(). However, I would have placed it in
> > tracepoint.h rather than tracepoint-defs.h, and we should figure out
> > why people complain that tracepoint.h is including headers too
> > eagerly.
>
> I could see if it would work in tracepoints.h.
>
> It might. I was just being extra cautious.

Well that blew up quick!

Try using tracepoint.h in include/linux/page_ref.h and
arch/x86/include/asm/msr.h and see what happens.

CC arch/x86/kernel/asm-offsets.s
In file included from /work/git/linux-trace.git/include/linux/srcu.h:20,
from /work/git/linux-trace.git/include/linux/tracepoint.h:16,
from /work/git/linux-trace.git/arch/x86/include/asm/msr.h:68,
from /work/git/linux-trace.git/arch/x86/include/asm/processor.h:22,
from /work/git/linux-trace.git/arch/x86/include/asm/cpufeature.h:5,
from /work/git/linux-trace.git/arch/x86/include/asm/thread_info.h:53,
from /work/git/linux-trace.git/include/linux/thread_info.h:38,
from /work/git/linux-trace.git/arch/x86/include/asm/preempt.h:7,
from /work/git/linux-trace.git/include/linux/preempt.h:78,
from /work/git/linux-trace.git/include/linux/spinlock.h:51,
from /work/git/linux-trace.git/include/linux/mmzone.h:8,
from /work/git/linux-trace.git/include/linux/gfp.h:6,
from /work/git/linux-trace.git/include/linux/slab.h:15,
from /work/git/linux-trace.git/include/linux/crypto.h:20,
from /work/git/linux-trace.git/arch/x86/kernel/asm-offsets.c:9:
/work/git/linux-trace.git/include/linux/rcupdate.h: In function ‘rcu_read_lock_sched’:
/work/git/linux-trace.git/include/linux/rcupdate.h:740:2: error: implicit declaration of function ‘preempt_disable’ [-Werror=implicit-function-declaration]
740 | preempt_disable();
| ^~~~~~~~~~~~~~~
/work/git/linux-trace.git/include/linux/rcupdate.h: In function ‘rcu_read_lock_sched_notrace’:
/work/git/linux-trace.git/include/linux/rcupdate.h:750:2: error: implicit declaration of function ‘preempt_disable_notrace’; did you mean ‘paravirt_disable_iospace’? [-Werror=implicit-function-declaration]
750 | preempt_disable_notrace();
| ^~~~~~~~~~~~~~~~~~~~~~~
| paravirt_disable_iospace
/work/git/linux-trace.git/include/linux/rcupdate.h: In function ‘rcu_read_unlock_sched’:
/work/git/linux-trace.git/include/linux/rcupdate.h:765:2: error: implicit declaration of function ‘preempt_enable’ [-Werror=implicit-function-declaration]
765 | preempt_enable();
| ^~~~~~~~~~~~~~
/work/git/linux-trace.git/include/linux/rcupdate.h: In function ‘rcu_read_unlock_sched_notrace’:
/work/git/linux-trace.git/include/linux/rcupdate.h:772:2: error: implicit declaration of function ‘preempt_enable_notrace’ [-Werror=implicit-function-declaration]
772 | preempt_enable_notrace();
| ^~~~~~~~~~~~~~~~~~~~~~

-- Steve