Messages in this thread | | | Date | Mon, 21 Sep 2009 21:30:34 +0100 | From | Dave <> | Subject | Re: [patch 1/2] spinlocks: check spinlock_t/rwlock_t argument type on non-SMP builds |
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Andrew Morton wrote: > On Mon, 21 Sep 2009 09:43:52 +0200 > Ingo Molnar <mingo@elte.hu> wrote: > >> * akpm@linux-foundation.org <akpm@linux-foundation.org> wrote: >> >>> From: David Kilroy <kilroyd@googlemail.com> >>> >>> When writing code for UP without CONFIG_DEBUG_SPINLOCK it's easy to get >>> the first argument to the spinlock/rwlock functions wrong. This is >>> because the parameter is not actually used in this configuration. >>> >>> Typically you will only find out it's wrong >>> * by rebuilding with CONFIG_SMP or CONFIG_DEBUG_SPINLOCK >>> * after you've submitted your beautiful patch series. >>> >>> The first means a long wait, and the latter is a bit late. >>> >>> Change the intermediate macros into inline functions. >>> >>> Signed-off-by: David Kilroy <kilroyd@googlemail.com> >>> Cc: Ingo Molnar <mingo@elte.hu> >>> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> >>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> >>> --- >>> >>> include/linux/spinlock.h | 6 - >>> include/linux/spinlock_api_up.h | 118 ++++++++++++++++++++++-------- >>> 2 files changed, 92 insertions(+), 32 deletions(-) >>> >>> diff -puN include/linux/spinlock.h~spinlocks-check-spinlock_t-rwlock_t-argument-type-on-non-smp-builds include/linux/spinlock.h >>> --- a/include/linux/spinlock.h~spinlocks-check-spinlock_t-rwlock_t-argument-type-on-non-smp-builds >>> +++ a/include/linux/spinlock.h >>> @@ -240,17 +240,17 @@ static inline void smp_mb__after_lock(vo >>> #define spin_lock_irqsave(lock, flags) \ >>> do { \ >>> typecheck(unsigned long, flags); \ >>> - _spin_lock_irqsave(lock, flags); \ >>> + _spin_lock_irqsave(lock, &flags); \ >>> } while (0) >>> #define read_lock_irqsave(lock, flags) \ >>> do { \ >>> typecheck(unsigned long, flags); \ >>> - _read_lock_irqsave(lock, flags); \ >>> + _read_lock_irqsave(lock, &flags); \ >>> } while (0) >> these bits broke the Alpha build: >> >> /home/mingo/tip/arch/alpha/include/asm/core_t2.h: In function 't2_readb': >> /home/mingo/tip/arch/alpha/include/asm/core_t2.h:451: error: '_spin_lock_irqsave' is static but used in inline function 't2_readb' which is not static > > hm. What the heck does that mean? > > __EXTERN_INLINE u8 t2_readb(const volatile void __iomem *xaddr) > > Something to do with the extern-inline?
This came up the last time this went into Ingos tree. And yes, it's the extern inlines using the spinlock functions that causes the error.
> Do you have the .config? My alpha builds went OK.
Last I checked, you need to have: CONFIG_SMP=N CONFIG_DEBUG_SPINLOCK=N
The latter gets auto-selected, so I set: CONFIG_DEBUG_LOCK_ALLOC=N CONFIG_LOCK_STAT=N CONFIG_PROVE_LOCKING=N CONFIG_LOCK_STAT=N
Regards,
Dave.
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