On Fri, Aug 29, 2025 at 01:07:31AM -0700, Ankur Arora wrote: > Add smp_cond_load_relaxed_timewait(), which extends > smp_cond_load_relaxed() to allow waiting for a finite duration. > > The additional parameter allows for the timeout check. > > The waiting is done via the usual cpu_relax() spin-wait around the > condition variable with periodic evaluation of the time-check. > > The number of times we spin is defined by SMP_TIMEWAIT_SPIN_COUNT > (chosen to be 200 by default) which, assuming each cpu_relax() > iteration takes around 20-30 cycles (measured on a variety of x86 > platforms), amounts to around 4000-6000 cycles. > > Cc: Arnd Bergmann <arnd@xxxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: linux-arch@xxxxxxxxxxxxxxx > Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx> Apart from the name, this looks fine (I'd have preferred the "timeout" suffix). Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
