Hello Daniel and Ingo, I use 2.6.23-rt1 and the patch of Daniel below which seems to be in there breaks the compilation of the RT-kernel when CONFIG_GENERIC_TIME is NOT set. It breaks in the do_gettimeofday(struct timeval *tv) code in the architecture specific code where there is a call to: seq = read_seqbegin_irqsave(&xtime_lock, flags); The PICK_FUNCTION implementation does not return anything, so the compile breaks here. I am figuring out how to solve this problem nicely, but I have not found a nice solution yet. Attached I have put my hack to make it compile on ARM again, but maybe one of you can do a better proposal to fix this. Here is a list of files that will probably all fail to build: (I only tested ARM) linux-2.6.23/arch/arm/kernel/time.c:254 linux-2.6.23/arch/xtensa/kernel/time.c:132 linux-2.6.23/arch/sparc/kernel/time.c:453 linux-2.6.23/arch/sparc/kernel/pcic.c:776 linux-2.6.23/arch/blackfin/kernel/time.c:269 linux-2.6.23/arch/m68knommu/kernel/time.c:130 linux-2.6.23/arch/sh64/kernel/time.c:193 linux-2.6.23/arch/alpha/kernel/time.c:408 linux-2.6.23/arch/sh/kernel/time.c:65 linux-2.6.23/arch/m68k/kernel/time.c:104 linux-2.6.23/arch/ppc/kernel/time.c:207 linux-2.6.23/arch/s390/kernel/time.c:197 Kind Regards, Remy Bohmer 2007/8/28, Daniel Walker <dwalker@xxxxxxxxxx>: > Replace the old PICK_OP style macros with PICK_FUNCTION. Although, > seqlocks has some alien code, which I also replaced as can be seen > from the line count below. > > Signed-off-by: Daniel Walker <dwalker@xxxxxxxxxx> > > --- > include/linux/pickop.h | 4 > include/linux/seqlock.h | 235 +++++++++++++++++++++++++++--------------------- > 2 files changed, 135 insertions(+), 104 deletions(-) > > Index: linux-2.6.22/include/linux/pickop.h > =================================================================== > --- linux-2.6.22.orig/include/linux/pickop.h > +++ linux-2.6.22/include/linux/pickop.h > @@ -1,10 +1,6 @@ > #ifndef _LINUX_PICKOP_H > #define _LINUX_PICKOP_H > > -#undef TYPE_EQUAL > -#define TYPE_EQUAL(var, type) \ > - __builtin_types_compatible_p(typeof(var), type *) > - > #undef PICK_TYPE_EQUAL > #define PICK_TYPE_EQUAL(var, type) \ > __builtin_types_compatible_p(typeof(var), type) > Index: linux-2.6.22/include/linux/seqlock.h > =================================================================== > --- linux-2.6.22.orig/include/linux/seqlock.h > +++ linux-2.6.22/include/linux/seqlock.h > @@ -90,6 +90,12 @@ static inline void __write_seqlock(seqlo > smp_wmb(); > } > > +static __always_inline unsigned long __write_seqlock_irqsave(seqlock_t *sl) > +{ > + __write_seqlock(sl); > + return 0; > +} > + > static inline void __write_sequnlock(seqlock_t *sl) > { > smp_wmb(); > @@ -97,6 +103,8 @@ static inline void __write_sequnlock(seq > spin_unlock(&sl->lock); > } > > +#define __write_sequnlock_irqrestore(sl, flags) __write_sequnlock(sl) > + > static inline int __write_tryseqlock(seqlock_t *sl) > { > int ret = spin_trylock(&sl->lock); > @@ -149,6 +157,28 @@ static __always_inline void __write_seql > smp_wmb(); > } > > +static __always_inline unsigned long > +__write_seqlock_irqsave_raw(raw_seqlock_t *sl) > +{ > + unsigned long flags; > + > + local_irq_save(flags); > + __write_seqlock_raw(sl); > + return flags; > +} > + > +static __always_inline void __write_seqlock_irq_raw(raw_seqlock_t *sl) > +{ > + local_irq_disable(); > + __write_seqlock_raw(sl); > +} > + > +static __always_inline void __write_seqlock_bh_raw(raw_seqlock_t *sl) > +{ > + local_bh_disable(); > + __write_seqlock_raw(sl); > +} > + > static __always_inline void __write_sequnlock_raw(raw_seqlock_t *sl) > { > smp_wmb(); > @@ -156,6 +186,27 @@ static __always_inline void __write_sequ > spin_unlock(&sl->lock); > } > > +static __always_inline void > +__write_sequnlock_irqrestore_raw(raw_seqlock_t *sl, unsigned long flags) > +{ > + __write_sequnlock_raw(sl); > + local_irq_restore(flags); > + preempt_check_resched(); > +} > + > +static __always_inline void __write_sequnlock_irq_raw(raw_seqlock_t *sl) > +{ > + __write_sequnlock_raw(sl); > + local_irq_enable(); > + preempt_check_resched(); > +} > + > +static __always_inline void __write_sequnlock_bh_raw(raw_seqlock_t *sl) > +{ > + __write_sequnlock_raw(sl); > + local_bh_enable(); > +} > + > static __always_inline int __write_tryseqlock_raw(raw_seqlock_t *sl) > { > int ret = spin_trylock(&sl->lock); > @@ -182,60 +233,93 @@ static __always_inline int __read_seqret > > extern int __bad_seqlock_type(void); > > -#define PICK_SEQOP(op, lock) \ > +/* > + * PICK_SEQ_OP() is a small redirector to allow less typing of the lock > + * types raw_seqlock_t, seqlock_t, at the front of the PICK_FUNCTION > + * macro. > + */ > +#define PICK_SEQ_OP(...) \ > + PICK_FUNCTION(raw_seqlock_t *, seqlock_t *, ##__VA_ARGS__) > +#define PICK_SEQ_OP_RET(...) \ > + PICK_FUNCTION_RET(raw_seqlock_t *, seqlock_t *, ##__VA_ARGS__) > + > +#define write_seqlock(sl) PICK_SEQ_OP(__write_seqlock_raw, __write_seqlock, sl) > + > +#define write_sequnlock(sl) \ > + PICK_SEQ_OP(__write_sequnlock_raw, __write_sequnlock, sl) > + > +#define write_tryseqlock(sl) \ > + PICK_SEQ_OP_RET(__write_tryseqlock_raw, __write_tryseqlock, sl) > + > +#define read_seqbegin(sl) \ > + PICK_SEQ_OP_RET(__read_seqbegin_raw, __read_seqbegin, sl) > + > +#define read_seqretry(sl, iv) \ > + PICK_SEQ_OP_RET(__read_seqretry_raw, __read_seqretry, sl, iv) > + > +#define write_seqlock_irqsave(lock, flags) \ > do { \ > - if (TYPE_EQUAL((lock), raw_seqlock_t)) \ > - op##_raw((raw_seqlock_t *)(lock)); \ > - else if (TYPE_EQUAL((lock), seqlock_t)) \ > - op((seqlock_t *)(lock)); \ > - else __bad_seqlock_type(); \ > + flags = PICK_SEQ_OP_RET(__write_seqlock_irqsave_raw, \ > + __write_seqlock_irqsave, lock); \ > } while (0) > > -#define PICK_SEQOP_RET(op, lock) \ > -({ \ > - unsigned long __ret; \ > - \ > - if (TYPE_EQUAL((lock), raw_seqlock_t)) \ > - __ret = op##_raw((raw_seqlock_t *)(lock)); \ > - else if (TYPE_EQUAL((lock), seqlock_t)) \ > - __ret = op((seqlock_t *)(lock)); \ > - else __ret = __bad_seqlock_type(); \ > - \ > - __ret; \ > -}) > - > -#define PICK_SEQOP_CONST_RET(op, lock) \ > -({ \ > - unsigned long __ret; \ > - \ > - if (TYPE_EQUAL((lock), raw_seqlock_t)) \ > - __ret = op##_raw((const raw_seqlock_t *)(lock));\ > - else if (TYPE_EQUAL((lock), seqlock_t)) \ > - __ret = op((seqlock_t *)(lock)); \ > - else __ret = __bad_seqlock_type(); \ > - \ > - __ret; \ > -}) > - > -#define PICK_SEQOP2_CONST_RET(op, lock, arg) \ > - ({ \ > - unsigned long __ret; \ > - \ > - if (TYPE_EQUAL((lock), raw_seqlock_t)) \ > - __ret = op##_raw((const raw_seqlock_t *)(lock), (arg)); \ > - else if (TYPE_EQUAL((lock), seqlock_t)) \ > - __ret = op((seqlock_t *)(lock), (arg)); \ > - else __ret = __bad_seqlock_type(); \ > - \ > - __ret; \ > -}) > - > - > -#define write_seqlock(sl) PICK_SEQOP(__write_seqlock, sl) > -#define write_sequnlock(sl) PICK_SEQOP(__write_sequnlock, sl) > -#define write_tryseqlock(sl) PICK_SEQOP_RET(__write_tryseqlock, sl) > -#define read_seqbegin(sl) PICK_SEQOP_CONST_RET(__read_seqbegin, sl) > -#define read_seqretry(sl, iv) PICK_SEQOP2_CONST_RET(__read_seqretry, sl, iv) > +#define write_seqlock_irq(lock) \ > + PICK_SEQ_OP(__write_seqlock_irq_raw, __write_seqlock, lock) > + > +#define write_seqlock_bh(lock) \ > + PICK_SEQ_OP(__write_seqlock_bh_raw, __write_seqlock, lock) > + > +#define write_sequnlock_irqrestore(lock, flags) \ > + PICK_SEQ_OP(__write_sequnlock_irqrestore_raw, \ > + __write_sequnlock_irqrestore, lock, flags) > + > +#define write_sequnlock_bh(lock) \ > + PICK_SEQ_OP(__write_sequnlock_bh_raw, __write_sequnlock, lock) > + > +#define write_sequnlock_irq(lock) \ > + PICK_SEQ_OP(__write_sequnlock_irq_raw, __write_sequnlock, lock) > + > +static __always_inline > +unsigned long __read_seqbegin_irqsave_raw(raw_seqlock_t *sl) > +{ > + unsigned long flags; > + > + local_irq_save(flags); > + __read_seqbegin_raw(sl); > + return flags; > +} > + > +static __always_inline unsigned long __read_seqbegin_irqsave(seqlock_t *sl) > +{ > + __read_seqbegin(sl); > + return 0; > +} > + > +#define read_seqbegin_irqsave(lock, flags) \ > +do { \ > + flags = PICK_SEQ_OP_RET(__read_seqbegin_irqsave_raw, \ > + __read_seqbegin_irqsave, lock); \ > +} while (0) > + > +static __always_inline int > +__read_seqretry_irqrestore(seqlock_t *sl, unsigned iv, unsigned long flags) > +{ > + return __read_seqretry(sl, iv); > +} > + > +static __always_inline int > +__read_seqretry_irqrestore_raw(raw_seqlock_t *sl, unsigned iv, > + unsigned long flags) > +{ > + int ret = read_seqretry(sl, iv); > + local_irq_restore(flags); > + preempt_check_resched(); > + return ret; > +} > + > +#define read_seqretry_irqrestore(lock, iv, flags) \ > + PICK_SEQ_OP_RET(__read_seqretry_irqrestore_raw, \ > + __read_seqretry_irqrestore, lock, iv, flags) > > /* > * Version using sequence counter only. > @@ -286,53 +370,4 @@ static inline void write_seqcount_end(se > smp_wmb(); > s->sequence++; > } > - > -#define PICK_IRQOP(op, lock) \ > -do { \ > - if (TYPE_EQUAL((lock), raw_seqlock_t)) \ > - op(); \ > - else if (TYPE_EQUAL((lock), seqlock_t)) \ > - { /* nothing */ } \ > - else __bad_seqlock_type(); \ > -} while (0) > - > -#define PICK_IRQOP2(op, arg, lock) \ > -do { \ > - if (TYPE_EQUAL((lock), raw_seqlock_t)) \ > - op(arg); \ > - else if (TYPE_EQUAL(lock, seqlock_t)) \ > - { /* nothing */ } \ > - else __bad_seqlock_type(); \ > -} while (0) > - > - > - > -/* > - * Possible sw/hw IRQ protected versions of the interfaces. > - */ > -#define write_seqlock_irqsave(lock, flags) \ > - do { PICK_IRQOP2(local_irq_save, flags, lock); write_seqlock(lock); } while (0) > -#define write_seqlock_irq(lock) \ > - do { PICK_IRQOP(local_irq_disable, lock); write_seqlock(lock); } while (0) > -#define write_seqlock_bh(lock) \ > - do { PICK_IRQOP(local_bh_disable, lock); write_seqlock(lock); } while (0) > - > -#define write_sequnlock_irqrestore(lock, flags) \ > - do { write_sequnlock(lock); PICK_IRQOP2(local_irq_restore, flags, lock); preempt_check_resched(); } while(0) > -#define write_sequnlock_irq(lock) \ > - do { write_sequnlock(lock); PICK_IRQOP(local_irq_enable, lock); preempt_check_resched(); } while(0) > -#define write_sequnlock_bh(lock) \ > - do { write_sequnlock(lock); PICK_IRQOP(local_bh_enable, lock); } while(0) > - > -#define read_seqbegin_irqsave(lock, flags) \ > - ({ PICK_IRQOP2(local_irq_save, flags, lock); read_seqbegin(lock); }) > - > -#define read_seqretry_irqrestore(lock, iv, flags) \ > - ({ \ > - int ret = read_seqretry(lock, iv); \ > - PICK_IRQOP2(local_irq_restore, flags, lock); \ > - preempt_check_resched(); \ > - ret; \ > - }) > - > #endif /* __LINUX_SEQLOCK_H */ > > -- > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
This patch is hack that makes the RT-kernel compile again when CONFIG_GENERIC_TIME is NOT set. Probably every architecture has the same problem because the read_seqbegin_irqsave() macro has been changed to something not returning anything. Signed-off-by: Remy Bohmer <linux@xxxxxxxxxx> --- arch/arm/kernel/time.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Index: linux-2.6.23/arch/arm/kernel/time.c =================================================================== --- linux-2.6.23.orig/arch/arm/kernel/time.c 2007-10-16 09:17:25.000000000 +0200 +++ linux-2.6.23/arch/arm/kernel/time.c 2007-10-16 10:08:02.000000000 +0200 @@ -251,7 +251,8 @@ void do_gettimeofday(struct timeval *tv) unsigned long usec, sec; do { - seq = read_seqbegin_irqsave(&xtime_lock, flags); + read_seqbegin_irqsave(&xtime_lock, flags); + seq = xtime_lock.sequence; usec = system_timer->offset(); sec = xtime.tv_sec; usec += xtime.tv_nsec / 1000;