From mboxrd@z Thu Jan 1 00:00:00 1970 From: Weizhao Ouyang Date: Wed, 08 Sep 2021 03:52:33 +0000 Subject: Re: [PATCH v3] ftrace: Cleanup ftrace_dyn_arch_init() Message-Id: List-Id: References: <20210907100524.1454928-1-o451686892@gmail.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: LEROY Christophe , Steven Rostedt , Ingo Molnar Cc: Rich Felker , "linux-ia64@vger.kernel.org" , "linux-sh@vger.kernel.org" , "linux-mips@vger.kernel.org" , "James E.J. Bottomley" , Guo Ren , "H. Peter Anvin" , "sparclinux@vger.kernel.org" , "linux-riscv@lists.infradead.org" , Vincent Chen , Will Deacon , "linux-s390@vger.kernel.org" , Yoshinori Sato , Helge Deller , "x86@kernel.org" , Russell King , "linux-csky@vger.kernel.org" , Christian Borntraeger , Catalin Marinas , Albert Ou , Vasily Gorbik , Heiko Carstens , Borislav Petkov , Greentime Hu , Paul Walmsley , Thomas Gleixner , "linux-arm-kernel@lists.infradead.org" , Michal Simek , Thomas Bogendoerfer , "linux-parisc@vger.kernel.org" , Nick Hu , "linux-kernel@vger.kernel.org" , Palmer Dabbelt , Paul Mackerras , "linuxppc-dev@lists.ozlabs.org" , "David S. Miller" Thanks for reply. On 2021/9/7 23:55, LEROY Christophe wrote: > >> -----Message d'origine----- >> De : Linuxppc-dev > bounces+christophe.leroy=csgroup.eu@lists.ozlabs.org> De la part de Weizhao >> Ouyang >> >> Most of ARCHs use empty ftrace_dyn_arch_init(), introduce a weak common >> ftrace_dyn_arch_init() to cleanup them. >> >> Signed-off-by: Weizhao Ouyang >> Acked-by: Heiko Carstens (s390) >> Acked-by: Helge Deller (parisc) >> >> --- >> Changes in v3: >> -- fix unrecognized opcode on PowerPC >> >> Changes in v2: >> -- correct CONFIG_DYNAMIC_FTRACE on PowerPC >> -- add Acked-by tag >> >> --- >> arch/arm/kernel/ftrace.c | 5 ----- >> arch/arm64/kernel/ftrace.c | 5 ----- >> arch/csky/kernel/ftrace.c | 5 ----- >> arch/ia64/kernel/ftrace.c | 6 ------ >> arch/microblaze/kernel/ftrace.c | 5 ----- >> arch/mips/include/asm/ftrace.h | 2 ++ >> arch/nds32/kernel/ftrace.c | 5 ----- >> arch/parisc/kernel/ftrace.c | 5 ----- >> arch/powerpc/include/asm/ftrace.h | 4 ++++ >> arch/riscv/kernel/ftrace.c | 5 ----- >> arch/s390/kernel/ftrace.c | 5 ----- >> arch/sh/kernel/ftrace.c | 5 ----- >> arch/sparc/kernel/ftrace.c | 5 ----- >> arch/x86/kernel/ftrace.c | 5 ----- >> include/linux/ftrace.h | 1 - >> kernel/trace/ftrace.c | 5 +++++ >> 16 files changed, 11 insertions(+), 62 deletions(-) >> >> diff --git a/arch/mips/include/asm/ftrace.h b/arch/mips/include/asm/ftrace.h >> index b463f2aa5a61..ed013e767390 100644 >> --- a/arch/mips/include/asm/ftrace.h >> +++ b/arch/mips/include/asm/ftrace.h >> @@ -76,6 +76,8 @@ do { \ >> >> >> #ifdef CONFIG_DYNAMIC_FTRACE >> +int __init ftrace_dyn_arch_init(void); >> + > Why ? > > >> static inline unsigned long ftrace_call_adjust(unsigned long addr) >> { >> return addr; >> diff --git a/arch/powerpc/include/asm/ftrace.h >> b/arch/powerpc/include/asm/ftrace.h >> index debe8c4f7062..b05c43f13a4d 100644 >> --- a/arch/powerpc/include/asm/ftrace.h >> +++ b/arch/powerpc/include/asm/ftrace.h >> @@ -126,6 +126,10 @@ static inline void this_cpu_enable_ftrace(void) { } >> static inline void this_cpu_set_ftrace_enabled(u8 ftrace_enabled) { } >> static inline u8 this_cpu_get_ftrace_enabled(void) { return 1; } >> #endif /* CONFIG_PPC64 */ >> + >> +#ifdef CONFIG_DYNAMIC_FTRACE >> +int __init ftrace_dyn_arch_init(void); >> +#endif /* CONFIG_DYNAMIC_FTRACE */ > Why ? > >> #endif /* !__ASSEMBLY__ */ >> >> #endif /* _ASM_POWERPC_FTRACE */ >> diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h >> index 832e65f06754..f1eca123d89d 100644 >> --- a/include/linux/ftrace.h >> +++ b/include/linux/ftrace.h >> @@ -573,7 +573,6 @@ ftrace_set_early_filter(struct ftrace_ops *ops, char >> *buf, int enable); >> >> /* defined in arch */ >> extern int ftrace_ip_converted(unsigned long ip); >> -extern int ftrace_dyn_arch_init(void); > Why removing that ? > > Have you tried to build kernel/trace/ftrace.o with C=2 ? It will likely tell you that the function is not declared and that it should be static Yes I missed this check. Under the situation, the function should be static. > We could eventually consider that in the past, this generic declaration was unrelevant because the definitions where in the arch specific sections. > Now that you are implementing a generic weak version of this function, it would make sense to have a generic declaration as well. > > I really don't see the point in duplicating the declaration of the function in the arch specific headers. I use declaration in arch specific headers in tend to clarify the arch has implement ftrace_dyn_arch_init(). Anyway, it maybe pointless, a generic declaration is enough. Will update it later. >> extern void ftrace_replace_code(int enable); >> extern int ftrace_update_ftrace_func(ftrace_func_t func); >> extern void ftrace_caller(void); > Christophe > > CS Group - Document Interne