On 04/03/2018 02:43 PM, David Howells wrote: > Alan Stern <st...@rowland.harvard.edu> wrote: > >> + * Returns: 1 if @lock is locked, 0 otherwise. >> + * However, on !CONFIG_SMP builds with !CONFIG_DEBUG_SPINLOCK, >> + * the return value is always 0 (see include/linux/spinlock_up.h). >> + * Therefore you should not rely heavily on the return value. > > Seems reasonable. > > It might also want to include a note that the lock isn't necessarily held by > your own CPU. I would also use "=n" rather than "!", so maybe something like: > > * Returns: 1 if @lock is locked, 0 otherwise. > * > * Note that the function only tells you that the CPU is seen to be locked,
the CPU is locked?? > * not that it is locked on your CPU. > * > * Further, on CONFIG_SMP=n builds with CONFIG_DEBUG_SPINLOCK=n, the return > * value is always 0 (see include/linux/spinlock_up.h). Therefore you should > * not rely heavily on the return value. > > David > -- ~Randy
