On 2019/2/12 17:14, Li, Aubrey wrote: > On 2019/2/12 16:22, Thomas Gleixner wrote: >> On Tue, 12 Feb 2019, Aubrey Li wrote: >>> diff --git a/arch/x86/include/asm/processor.h >>> b/arch/x86/include/asm/processor.h >>> index d53c54b842da..60ee932070fe 100644 >>> --- a/arch/x86/include/asm/processor.h >>> +++ b/arch/x86/include/asm/processor.h >>> @@ -996,5 +996,7 @@ enum l1tf_mitigations { >>> }; >>> >>> extern enum l1tf_mitigations l1tf_mitigation; >>> +/* Add support for architecture specific output in /proc/pid/status */ >>> +extern void arch_proc_pid_status(struct seq_file *m, struct task_struct >>> *task); >> >> Sigh. This is absolutely the wrong place. The weak function is declared and >> used in fs/proc/... So the prototype wants to be in a header which is >> included from there independent of x86... > > Can the prototype be in the architecture header if they want to call the > function? > Like the following? arch_report_meminfo() is used in fs/proc/... as well. > > $ find . -name *.h | xargs grep arch_report_meminfo > ./arch/s390/include/asm/pgtable.h:void arch_report_meminfo(struct seq_file > *m); > ./arch/x86/include/asm/pgtable_types.h:extern void arch_report_meminfo(struct > seq_file *m); > ./arch/parisc/include/asm/pgtable.h:extern void arch_report_meminfo(struct > seq_file *m); >
Actually both way exist in the current kernel,the reason I chose to put the prototype into architecture header file is that I found some architectures rename the function name by a micro definition while others use prototype. See below: $ find . -name *.h | xargs grep arch_irq_stat ./arch/arm64/include/asm/hardirq.h:#define arch_irq_stat_cpu smp_irq_stat_cpu ./arch/arm/include/asm/hardirq.h:#define arch_irq_stat_cpu smp_irq_stat_cpu ./arch/x86/include/asm/hardirq.h:extern u64 arch_irq_stat_cpu(unsigned int cpu); This looks more flexible than it in the common header file. Anyway, putting the prototype into the common header file like include/linux/proc_fs.h is also acceptable to me if you persist, please just let me know, :) Thanks, -Aubrey