Messages in this thread | | | Subject | Re: [Fwd: Re: connector is missing in 2.6.12-rc2-mm1] | From | Evgeniy Polyakov <> | Date | Fri, 08 Apr 2005 10:12:07 +0400 |
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On Fri, 2005-04-08 at 09:19 +0400, Evgeniy Polyakov wrote: > On Fri, 2005-04-08 at 15:08 +1000, Herbert Xu wrote: > > On Fri, Apr 08, 2005 at 09:11:56AM +0400, Evgeniy Polyakov wrote: > > > > > > > Yes but what will go wrong on uni-processor MIPS when you don't do the > > > > sync in atomic_sub_return? > > > > > > Sync synchornizes cached mamory access, > > > without it new value may be stored only into cache, > > > but not into memory. > > > > I know, the same thing holds for most architectures, including i386. > > However, this is not an issue for uni-processor kernels anywhere else, > > so what's so special about MIPS? > > Does i386 or ppc has cached and uncached memory? > No, i386, ppc and others do not require sync on uncached memory access, > and only instruction not data cache sync on SMP.
Ugh, now I see your point :) For UP we may have some nitpics with DMA, but I doubt anyone will use atomic pointer for DMA. sync will not be an issue in atomic ops.
> > Cheers, -- Evgeniy Polyakov
Crash is better than data corruption -- Arthur Grabowski [unhandled content-type:application/pgp-signature] | |