| Message ID | 72d3e8c38f729dc22cb3235319b72f96190e01ee.1537802981.git.christophe.leroy@c-s.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC,v1,1/9] timer: fix circular header dependency | expand |
Le 24/09/2018 à 17:52, Christophe Leroy a écrit : > When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h > has to be included in asm/smp.h for the following change, in order > to avoid uncomplete definition of task_struct: > > -#define raw_smp_processor_id() (current_thread_info()->cpu) > +#define raw_smp_processor_id() (current->cpu) > > But this generates the following compilation error, due to circular > header dependency. > > CC kernel/time/alarmtimer.o > In file included from ./arch/powerpc/include/asm/smp.h:31, > from ./include/linux/smp.h:64, > from ./include/linux/percpu.h:7, > from ./include/linux/hrtimer.h:22, > from kernel/time/alarmtimer.c:19: > ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type > struct hrtimer dl_timer; > ^~~~~~~~ > ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type > struct hrtimer inactive_timer; > ^~~~~~~~~~~~~~ > make[1]: *** [kernel/time/alarmtimer.o] Error 1 > make: *** [kernel/time/alarmtimer.o] Error 2 > > CC fs/timerfd.o > In file included from ./arch/powerpc/include/asm/smp.h:31, > from ./include/linux/smp.h:64, > from ./include/linux/percpu.h:7, > from ./include/linux/hrtimer.h:22, > from ./include/linux/alarmtimer.h:6, > from fs/timerfd.c:12: > ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type > struct hrtimer dl_timer; > ^~~~~~~~ > ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type > struct hrtimer inactive_timer; > ^~~~~~~~~~~~~~ > make[1]: *** [fs/timerfd.o] Error 1 > make: *** [fs/timerfd.o] Error 2 > > This patch fixes it by including linux/hrtimer.h after linux/sched.h > > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> > --- > Should it be fixed in powerpc instead ? In that case, how ? Any idea ? Looks like there are several other places where the problem occurs, so it has to be fixed in the powerpc headers instead. Seems like RISC arch faced the same issue, and fixed it the following way: /* * This is particularly ugly: it appears we can't actually get the definition * of task_struct here, but we need access to the CPU this task is running on. * Instead of using C we're using asm-offsets.h to get the current processor * ID. */ #define raw_smp_processor_id() (*((int*)((char*)get_current() + TASK_TI_CPU))) Unless someone has a better idea, I'll fixed it that way. Christophe > > fs/timerfd.c | 2 +- > kernel/time/alarmtimer.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/timerfd.c b/fs/timerfd.c > index d69ad801eb80..0fc01b241382 100644 > --- a/fs/timerfd.c > +++ b/fs/timerfd.c > @@ -9,12 +9,12 @@ > * > */ > > -#include <linux/alarmtimer.h> > #include <linux/file.h> > #include <linux/poll.h> > #include <linux/init.h> > #include <linux/fs.h> > #include <linux/sched.h> > +#include <linux/alarmtimer.h> > #include <linux/kernel.h> > #include <linux/slab.h> > #include <linux/list.h> > diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c > index fa5de5e8de61..5fb75c9b3f06 100644 > --- a/kernel/time/alarmtimer.c > +++ b/kernel/time/alarmtimer.c > @@ -16,11 +16,11 @@ > * published by the Free Software Foundation. > */ > #include <linux/time.h> > -#include <linux/hrtimer.h> > #include <linux/timerqueue.h> > #include <linux/rtc.h> > #include <linux/sched/signal.h> > #include <linux/sched/debug.h> > +#include <linux/hrtimer.h> > #include <linux/alarmtimer.h> > #include <linux/mutex.h> > #include <linux/platform_device.h> >
Le 25/09/2018 à 07:34, Christophe LEROY a écrit : > > > Le 24/09/2018 à 17:52, Christophe Leroy a écrit : >> When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h >> has to be included in asm/smp.h for the following change, in order >> to avoid uncomplete definition of task_struct: >> >> -#define raw_smp_processor_id() (current_thread_info()->cpu) >> +#define raw_smp_processor_id() (current->cpu) >> >> But this generates the following compilation error, due to circular >> header dependency. >> >> CC kernel/time/alarmtimer.o >> In file included from ./arch/powerpc/include/asm/smp.h:31, >> from ./include/linux/smp.h:64, >> from ./include/linux/percpu.h:7, >> from ./include/linux/hrtimer.h:22, >> from kernel/time/alarmtimer.c:19: >> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete >> type >> struct hrtimer dl_timer; >> ^~~~~~~~ >> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has >> incomplete type >> struct hrtimer inactive_timer; >> ^~~~~~~~~~~~~~ >> make[1]: *** [kernel/time/alarmtimer.o] Error 1 >> make: *** [kernel/time/alarmtimer.o] Error 2 >> >> CC fs/timerfd.o >> In file included from ./arch/powerpc/include/asm/smp.h:31, >> from ./include/linux/smp.h:64, >> from ./include/linux/percpu.h:7, >> from ./include/linux/hrtimer.h:22, >> from ./include/linux/alarmtimer.h:6, >> from fs/timerfd.c:12: >> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete >> type >> struct hrtimer dl_timer; >> ^~~~~~~~ >> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has >> incomplete type >> struct hrtimer inactive_timer; >> ^~~~~~~~~~~~~~ >> make[1]: *** [fs/timerfd.o] Error 1 >> make: *** [fs/timerfd.o] Error 2 >> >> This patch fixes it by including linux/hrtimer.h after linux/sched.h >> >> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> >> --- >> Should it be fixed in powerpc instead ? In that case, how ? Any idea ? > > > Looks like there are several other places where the problem occurs, so > it has to be fixed in the powerpc headers instead. > > Seems like RISC arch faced the same issue, and fixed it the following way: > > /* > * This is particularly ugly: it appears we can't actually get the > definition > * of task_struct here, but we need access to the CPU this task is > running on. > * Instead of using C we're using asm-offsets.h to get the current > processor > * ID. > */ > #define raw_smp_processor_id() (*((int*)((char*)get_current() + > TASK_TI_CPU))) > > > Unless someone has a better idea, I'll fixed it that way. Not easy. I'm stuck at the moment, because asm-offsets.h redefines a lot of things with the same name as in C, so when including asm-offsets.h in C it conflicts. Argh !. Need to fix all those duplicates ? Christophe > > Christophe > > >> >> fs/timerfd.c | 2 +- >> kernel/time/alarmtimer.c | 2 +- >> 2 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/fs/timerfd.c b/fs/timerfd.c >> index d69ad801eb80..0fc01b241382 100644 >> --- a/fs/timerfd.c >> +++ b/fs/timerfd.c >> @@ -9,12 +9,12 @@ >> * >> */ >> -#include <linux/alarmtimer.h> >> #include <linux/file.h> >> #include <linux/poll.h> >> #include <linux/init.h> >> #include <linux/fs.h> >> #include <linux/sched.h> >> +#include <linux/alarmtimer.h> >> #include <linux/kernel.h> >> #include <linux/slab.h> >> #include <linux/list.h> >> diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c >> index fa5de5e8de61..5fb75c9b3f06 100644 >> --- a/kernel/time/alarmtimer.c >> +++ b/kernel/time/alarmtimer.c >> @@ -16,11 +16,11 @@ >> * published by the Free Software Foundation. >> */ >> #include <linux/time.h> >> -#include <linux/hrtimer.h> >> #include <linux/timerqueue.h> >> #include <linux/rtc.h> >> #include <linux/sched/signal.h> >> #include <linux/sched/debug.h> >> +#include <linux/hrtimer.h> >> #include <linux/alarmtimer.h> >> #include <linux/mutex.h> >> #include <linux/platform_device.h> >>
On Tue, Sep 25, 2018 at 07:34:15AM +0200, Christophe LEROY wrote: > > > Le 24/09/2018 à 17:52, Christophe Leroy a écrit : > > When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h > > has to be included in asm/smp.h for the following change, in order > > to avoid uncomplete definition of task_struct: > > > > -#define raw_smp_processor_id() (current_thread_info()->cpu) > > +#define raw_smp_processor_id() (current->cpu) > > > > But this generates the following compilation error, due to circular > > header dependency. > > > > CC kernel/time/alarmtimer.o > > In file included from ./arch/powerpc/include/asm/smp.h:31, > > from ./include/linux/smp.h:64, > > from ./include/linux/percpu.h:7, > > from ./include/linux/hrtimer.h:22, > > from kernel/time/alarmtimer.c:19: > > ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type > > struct hrtimer dl_timer; > > ^~~~~~~~ > > ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type > > struct hrtimer inactive_timer; > > ^~~~~~~~~~~~~~ > > make[1]: *** [kernel/time/alarmtimer.o] Error 1 > > make: *** [kernel/time/alarmtimer.o] Error 2 > > > > CC fs/timerfd.o > > In file included from ./arch/powerpc/include/asm/smp.h:31, > > from ./include/linux/smp.h:64, > > from ./include/linux/percpu.h:7, > > from ./include/linux/hrtimer.h:22, > > from ./include/linux/alarmtimer.h:6, > > from fs/timerfd.c:12: > > ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type > > struct hrtimer dl_timer; > > ^~~~~~~~ > > ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type > > struct hrtimer inactive_timer; > > ^~~~~~~~~~~~~~ > > make[1]: *** [fs/timerfd.o] Error 1 > > make: *** [fs/timerfd.o] Error 2 > > > > This patch fixes it by including linux/hrtimer.h after linux/sched.h > > > > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> > > --- > > Should it be fixed in powerpc instead ? In that case, how ? Any idea ? > > > Looks like there are several other places where the problem occurs, so it > has to be fixed in the powerpc headers instead. > > Seems like RISC arch faced the same issue, and fixed it the following way: > > /* > * This is particularly ugly: it appears we can't actually get the > definition > * of task_struct here, but we need access to the CPU this task is running > on. > * Instead of using C we're using asm-offsets.h to get the current processor > * ID. > */ > #define raw_smp_processor_id() (*((int*)((char*)get_current() + > TASK_TI_CPU))) > > > Unless someone has a better idea, I'll fixed it that way. To solve this on arm64 we made the cpu number a percpu variable; see commit: 57c82954e77fa12c ("arm64: make cpu number a percpu variable") IIUC, you could do that by placing it in paca_struct. Thanks, Mark.
Le 25/09/2018 à 14:11, Mark Rutland a écrit : > On Tue, Sep 25, 2018 at 07:34:15AM +0200, Christophe LEROY wrote: >> >> >> Le 24/09/2018 à 17:52, Christophe Leroy a écrit : >>> When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h >>> has to be included in asm/smp.h for the following change, in order >>> to avoid uncomplete definition of task_struct: >>> >>> -#define raw_smp_processor_id() (current_thread_info()->cpu) >>> +#define raw_smp_processor_id() (current->cpu) >>> >>> But this generates the following compilation error, due to circular >>> header dependency. >>> >>> CC kernel/time/alarmtimer.o >>> In file included from ./arch/powerpc/include/asm/smp.h:31, >>> from ./include/linux/smp.h:64, >>> from ./include/linux/percpu.h:7, >>> from ./include/linux/hrtimer.h:22, >>> from kernel/time/alarmtimer.c:19: >>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type >>> struct hrtimer dl_timer; >>> ^~~~~~~~ >>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type >>> struct hrtimer inactive_timer; >>> ^~~~~~~~~~~~~~ >>> make[1]: *** [kernel/time/alarmtimer.o] Error 1 >>> make: *** [kernel/time/alarmtimer.o] Error 2 >>> >>> CC fs/timerfd.o >>> In file included from ./arch/powerpc/include/asm/smp.h:31, >>> from ./include/linux/smp.h:64, >>> from ./include/linux/percpu.h:7, >>> from ./include/linux/hrtimer.h:22, >>> from ./include/linux/alarmtimer.h:6, >>> from fs/timerfd.c:12: >>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type >>> struct hrtimer dl_timer; >>> ^~~~~~~~ >>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type >>> struct hrtimer inactive_timer; >>> ^~~~~~~~~~~~~~ >>> make[1]: *** [fs/timerfd.o] Error 1 >>> make: *** [fs/timerfd.o] Error 2 >>> >>> This patch fixes it by including linux/hrtimer.h after linux/sched.h >>> >>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> >>> --- >>> Should it be fixed in powerpc instead ? In that case, how ? Any idea ? >> >> >> Looks like there are several other places where the problem occurs, so it >> has to be fixed in the powerpc headers instead. >> >> Seems like RISC arch faced the same issue, and fixed it the following way: >> >> /* >> * This is particularly ugly: it appears we can't actually get the >> definition >> * of task_struct here, but we need access to the CPU this task is running >> on. >> * Instead of using C we're using asm-offsets.h to get the current processor >> * ID. >> */ >> #define raw_smp_processor_id() (*((int*)((char*)get_current() + >> TASK_TI_CPU))) >> >> >> Unless someone has a better idea, I'll fixed it that way. > > To solve this on arm64 we made the cpu number a percpu variable; see > commit: > > 57c82954e77fa12c ("arm64: make cpu number a percpu variable") Thanks, I'll have a look > IIUC, you could do that by placing it in paca_struct. By the way, it is already in PACA struct for PPC64. The issue is with PPC32, up to now it was in current_thread_info: #ifdef CONFIG_PPC64 #define raw_smp_processor_id() (local_paca->paca_index) #define hard_smp_processor_id() (get_paca()->hw_cpu_id) #else /* 32-bit */ extern int smp_hw_index[]; #define raw_smp_processor_id() (current_thread_info()->cpu) #define hard_smp_processor_id() (smp_hw_index[smp_processor_id()]) [..] #endif Christophe
On 09/25/2018 12:15 PM, Christophe LEROY wrote: > > > Le 25/09/2018 à 14:11, Mark Rutland a écrit : >> On Tue, Sep 25, 2018 at 07:34:15AM +0200, Christophe LEROY wrote: >>> >>> >>> Le 24/09/2018 à 17:52, Christophe Leroy a écrit : >>>> When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h >>>> has to be included in asm/smp.h for the following change, in order >>>> to avoid uncomplete definition of task_struct: >>>> >>>> -#define raw_smp_processor_id() (current_thread_info()->cpu) >>>> +#define raw_smp_processor_id() (current->cpu) >>>> >>>> But this generates the following compilation error, due to circular >>>> header dependency. >>>> >>>> CC kernel/time/alarmtimer.o >>>> In file included from ./arch/powerpc/include/asm/smp.h:31, >>>> from ./include/linux/smp.h:64, >>>> from ./include/linux/percpu.h:7, >>>> from ./include/linux/hrtimer.h:22, >>>> from kernel/time/alarmtimer.c:19: >>>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has >>>> incomplete type >>>> struct hrtimer dl_timer; >>>> ^~~~~~~~ >>>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has >>>> incomplete type >>>> struct hrtimer inactive_timer; >>>> ^~~~~~~~~~~~~~ >>>> make[1]: *** [kernel/time/alarmtimer.o] Error 1 >>>> make: *** [kernel/time/alarmtimer.o] Error 2 >>>> >>>> CC fs/timerfd.o >>>> In file included from ./arch/powerpc/include/asm/smp.h:31, >>>> from ./include/linux/smp.h:64, >>>> from ./include/linux/percpu.h:7, >>>> from ./include/linux/hrtimer.h:22, >>>> from ./include/linux/alarmtimer.h:6, >>>> from fs/timerfd.c:12: >>>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has >>>> incomplete type >>>> struct hrtimer dl_timer; >>>> ^~~~~~~~ >>>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has >>>> incomplete type >>>> struct hrtimer inactive_timer; >>>> ^~~~~~~~~~~~~~ >>>> make[1]: *** [fs/timerfd.o] Error 1 >>>> make: *** [fs/timerfd.o] Error 2 >>>> >>>> This patch fixes it by including linux/hrtimer.h after linux/sched.h >>>> >>>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> >>>> --- >>>> Should it be fixed in powerpc instead ? In that case, how ? Any >>>> idea ? >>> >>> >>> Looks like there are several other places where the problem occurs, >>> so it >>> has to be fixed in the powerpc headers instead. >>> >>> Seems like RISC arch faced the same issue, and fixed it the following >>> way: >>> >>> /* >>> * This is particularly ugly: it appears we can't actually get the >>> definition >>> * of task_struct here, but we need access to the CPU this task is >>> running >>> on. >>> * Instead of using C we're using asm-offsets.h to get the current >>> processor >>> * ID. >>> */ >>> #define raw_smp_processor_id() (*((int*)((char*)get_current() + >>> TASK_TI_CPU))) >>> >>> >>> Unless someone has a better idea, I'll fixed it that way. >> >> To solve this on arm64 we made the cpu number a percpu variable; see >> commit: >> >> 57c82954e77fa12c ("arm64: make cpu number a percpu variable") > > Thanks, I'll have a look > >> IIUC, you could do that by placing it in paca_struct. > > By the way, it is already in PACA struct for PPC64. > The issue is with PPC32, up to now it was in current_thread_info: > > #ifdef CONFIG_PPC64 > #define raw_smp_processor_id() (local_paca->paca_index) > #define hard_smp_processor_id() (get_paca()->hw_cpu_id) > #else > /* 32-bit */ > extern int smp_hw_index[]; > > #define raw_smp_processor_id() (current_thread_info()->cpu) > #define hard_smp_processor_id() (smp_hw_index[smp_processor_id()]) > > [..] > > #endif > It seems not that easy. Adding the following leads to the below failure. I'm having a hard time identifying and fixing the issue. Looks again like a circular thing, because linux/percpu-defs.h is where raw_cpu_ptr() is defined. --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -83,7 +83,14 @@ int is_cpu_dead(unsigned int cpu); /* 32-bit */ extern int smp_hw_index[]; -#define raw_smp_processor_id() (current_thread_info()->cpu) +DECLARE_PER_CPU_READ_MOSTLY(unsigned int, cpu_number); + +/* + * We don't use this_cpu_read(cpu_number) as that has implicit writes to + * preempt_count, and associated (compiler) barriers, that we'd like to avoid + * the expense of. If we're preemptible, the value can be stale at use anyway. + */ +#define raw_smp_processor_id() (*this_cpu_ptr(&cpu_number)) #define hard_smp_processor_id() (smp_hw_index[smp_processor_id()]) static inline int get_hard_smp_processor_id(int cpu) CC arch/powerpc/kernel/asm-offsets.s In file included from ././include/linux/compiler_types.h:64:0, from <command-line>:0: ./include/linux/percpu-rwsem.h: In function 'percpu_down_read_preempt_disable': ./include/linux/percpu-defs.h:254:27: error: implicit declaration of function 'raw_cpu_ptr' [-Werror=implicit-function-declaration] #define this_cpu_ptr(ptr) raw_cpu_ptr(ptr) ^ ./include/linux/compiler-gcc.h:58:26: note: in definition of macro 'RELOC_HIDE' (typeof(ptr)) (__ptr + (off)); \ ^ ./include/asm-generic/percpu.h:44:31: note: in expansion of macro 'SHIFT_PERCPU_PTR' #define arch_raw_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset) ^ ./include/asm-generic/percpu.h:31:25: note: in expansion of macro 'per_cpu_offset' #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id()) ^ ./arch/powerpc/include/asm/smp.h:93:35: note: in expansion of macro 'this_cpu_ptr' #define raw_smp_processor_id() (*this_cpu_ptr(&cpu_number)) ^ ./include/asm-generic/percpu.h:31:40: note: in expansion of macro 'raw_smp_processor_id' #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id()) ^ ./include/asm-generic/percpu.h:44:53: note: in expansion of macro '__my_cpu_offset' #define arch_raw_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset) ^ ./include/linux/percpu-defs.h:244:2: note: in expansion of macro 'arch_raw_cpu_ptr' arch_raw_cpu_ptr(ptr); \ ^ ./include/asm-generic/percpu.h:76:3: note: in expansion of macro 'raw_cpu_ptr' *raw_cpu_ptr(&(pcp)) op val; \ ^ ./include/asm-generic/percpu.h:225:34: note: in expansion of macro 'raw_cpu_generic_to_op' #define raw_cpu_add_1(pcp, val) raw_cpu_generic_to_op(pcp, val, +=) ^ ./include/linux/percpu-defs.h:379:11: note: in expansion of macro 'raw_cpu_add_1' case 1: stem##1(variable, __VA_ARGS__);break; \ ^ ./include/linux/percpu-defs.h:424:32: note: in expansion of macro '__pcpu_size_call' #define raw_cpu_add(pcp, val) __pcpu_size_call(raw_cpu_add_, pcp, val) ^ ./include/linux/percpu-defs.h:460:2: note: in expansion of macro 'raw_cpu_add' raw_cpu_add(pcp, val); \ ^ ./include/linux/percpu-defs.h:499:30: note: in expansion of macro '__this_cpu_add' #define __this_cpu_inc(pcp) __this_cpu_add(pcp, 1) ^ ./include/linux/percpu-rwsem.h:47:2: note: in expansion of macro '__this_cpu_inc' __this_cpu_inc(*sem->read_count); ^ ./arch/powerpc/include/asm/smp.h:93:34: error: invalid type argument of unary '*' (have 'int') #define raw_smp_processor_id() (*this_cpu_ptr(&cpu_number)) ^ [...]
diff --git a/fs/timerfd.c b/fs/timerfd.c index d69ad801eb80..0fc01b241382 100644 --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -9,12 +9,12 @@ * */ -#include <linux/alarmtimer.h> #include <linux/file.h> #include <linux/poll.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/sched.h> +#include <linux/alarmtimer.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/list.h> diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index fa5de5e8de61..5fb75c9b3f06 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -16,11 +16,11 @@ * published by the Free Software Foundation. */ #include <linux/time.h> -#include <linux/hrtimer.h> #include <linux/timerqueue.h> #include <linux/rtc.h> #include <linux/sched/signal.h> #include <linux/sched/debug.h> +#include <linux/hrtimer.h> #include <linux/alarmtimer.h> #include <linux/mutex.h> #include <linux/platform_device.h>
When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h has to be included in asm/smp.h for the following change, in order to avoid uncomplete definition of task_struct: -#define raw_smp_processor_id() (current_thread_info()->cpu) +#define raw_smp_processor_id() (current->cpu) But this generates the following compilation error, due to circular header dependency. CC kernel/time/alarmtimer.o In file included from ./arch/powerpc/include/asm/smp.h:31, from ./include/linux/smp.h:64, from ./include/linux/percpu.h:7, from ./include/linux/hrtimer.h:22, from kernel/time/alarmtimer.c:19: ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type struct hrtimer dl_timer; ^~~~~~~~ ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type struct hrtimer inactive_timer; ^~~~~~~~~~~~~~ make[1]: *** [kernel/time/alarmtimer.o] Error 1 make: *** [kernel/time/alarmtimer.o] Error 2 CC fs/timerfd.o In file included from ./arch/powerpc/include/asm/smp.h:31, from ./include/linux/smp.h:64, from ./include/linux/percpu.h:7, from ./include/linux/hrtimer.h:22, from ./include/linux/alarmtimer.h:6, from fs/timerfd.c:12: ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type struct hrtimer dl_timer; ^~~~~~~~ ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type struct hrtimer inactive_timer; ^~~~~~~~~~~~~~ make[1]: *** [fs/timerfd.o] Error 1 make: *** [fs/timerfd.o] Error 2 This patch fixes it by including linux/hrtimer.h after linux/sched.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- Should it be fixed in powerpc instead ? In that case, how ? Any idea ? fs/timerfd.c | 2 +- kernel/time/alarmtimer.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)