linux-kernel - Re: [RFC PATCH 09/11] asm-generic/tlb: Track which levels of the page tables have been cleared

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Date:   Tue, 28 Aug 2018 14:12:43 +0100
From:   Will Deacon <will.deacon@....com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     linux-kernel@...r.kernel.org, benh@....ibm.com,
        torvalds@...ux-foundation.org, npiggin@...il.com,
        catalin.marinas@....com, linux-arm-kernel@...ts.infradead.org
Subject: Re: [RFC PATCH 09/11] asm-generic/tlb: Track which levels of the
 page tables have been cleared

On Mon, Aug 27, 2018 at 09:53:41AM +0200, Peter Zijlstra wrote:
> On Fri, Aug 24, 2018 at 04:52:44PM +0100, Will Deacon wrote:
> > +static inline unsigned long tlb_get_unmap_granule(struct mmu_gather *tlb)
> > +{
> > +	if (tlb->cleared_ptes)
> > +		return PAGE_SIZE;
> > +	if (tlb->cleared_pmds)
> > +		return PMD_SIZE;
> > +	if (tlb->cleared_puds)
> > +		return PUD_SIZE;
> > +	if (tlb->cleared_p4ds)
> > +		return P4D_SIZE;
> > +
> > +	return PAGE_SIZE;
> > +}
> 
> When doing the x86 patch; I found _SHIFT more useful than _SIZE.

I'll make that change for the next version.

Cheers,

Will