Re: [PATCH v7 09/28] mm: Create FolioFlags

From: Peter Zijlstra
Date: Mon Apr 19 2021 - 09:41:08 EST


On Fri, Apr 09, 2021 at 07:50:46PM +0100, Matthew Wilcox (Oracle) wrote:
> These new functions are the folio analogues of the PageFlags functions.
> If CONFIG_DEBUG_VM_PGFLAGS is enabled, we check the folio is not a tail
> page at every invocation. Note that this will also catch the PagePoisoned
> case as a poisoned page has every bit set, which would include PageTail.
>
> This saves 1727 bytes of text with the distro-derived config that
> I'm testing due to removing a double call to compound_head() in
> PageSwapCache().

I vote for dropping the Camels if we're going to rework all this.