On Wed, Sep 19, 2018 at 01:28:29PM +0200, Peter Zijlstra wrote: > On Tue, Sep 18, 2018 at 03:10:34PM +0100, Will Deacon wrote: > > > So whilst I was reviewing this, I realised that I think we should be > > selecting HAVE_RCU_TABLE_INVALIDATE for arch/arm/ if HAVE_RCU_TABLE_FREE. > > Yes very much so. Let me invert that option, you normally want that, > except if you don't natively use the linux page-tables. Yeah, inverting this to be opt-out is definitely the safe thing to do. Patch below looks good: Acked-by: Will Deacon <will.deacon@xxxxxxx> Will > --- > Subject: asm-generic/tlb: Invert HAVE_RCU_TABLE_INVALIDATE > From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Date: Wed Sep 19 13:24:41 CEST 2018 > > Make issuing a TLB invalidate for page-table pages the normal case. > > The reason is twofold: > > - too many invalidates is safer than too few, > - most architectures use the linux page-tables natively > and would this require this. > > Make it an opt-out, instead of an opt-in. > > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
