Re: [PATCH] mm: fix page cache convergence regression

[Johannes Weiner]

On Fri, May 24, 2019 at 09:04:17AM -0700, Matthew Wilcox wrote:
> On Fri, May 24, 2019 at 11:31:48AM -0400, Johannes Weiner wrote:
> > diff --git a/include/linux/xarray.h b/include/linux/xarray.h
> > index 0e01e6129145..cbbf76e4c973 100644
> > --- a/include/linux/xarray.h
> > +++ b/include/linux/xarray.h
> > @@ -292,6 +292,7 @@ struct xarray {
> >  	spinlock_t	xa_lock;
> >  /* private: The rest of the data structure is not to be used directly. */
> >  	gfp_t		xa_flags;
> > +	gfp_t		xa_gfp;
> >  	void __rcu *	xa_head;
> >  };
> 
> No.  I'm willing to go for a xa_flag which says to use __GFP_ACCOUNT, but
> you can't add another element to the struct xarray.

Ok, we can generalize per-tree gfp flags later if necessary.

Below is the updated fix that uses an XA_FLAGS_ACCOUNT flag instead.

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