Re: [PATCH 05/17] asm-generic/tlb: Rename HAVE_RCU_TABLE_NO_INVALIDATE

[Peter Zijlstra]

On Mon, Dec 16, 2019 at 06:43:53PM +0530, Aneesh Kumar K.V wrote:
> On 12/16/19 6:07 PM, Peter Zijlstra wrote:

> > I'm confused, are you saing you're happy to have PowerPC eat the extra
> > TLB invalidates? I thought you cared about PPC performance :-)
> > 
> > 
> 
> Instead can we do
> 
> static inline void tlb_table_invalidate(struct mmu_gather *tlb)
> {
> #ifndef CONFIG_MMU_GATHER_RCU_TABLE_FREE
> 	 * Invalidate page-table caches used by hardware walkers. Then we still
> 	 * need to RCU-sched wait while freeing the pages because software
> 	 * walkers can still be in-flight.
> 	 */
> 	tlb_flush_mmu_tlbonly(tlb);
> #endif
> }

How does that not break ARM/ARM64/s390 and x86 ?