Re: [PATCH v6 7/9] mm: multigenerational lru: eviction

[Yu Zhao <yuzhao@google.com>]

On Tue, Jan 11, 2022 at 04:07:57PM +0530, Aneesh Kumar K.V wrote:
> ...
> 
>  +static int isolate_folios(struct lruvec *lruvec, struct scan_control *sc, int swappiness,
> > +			  int *type_scanned, struct list_head *list)
> > +{
> > +	int i;
> > +	int type;
> > +	int scanned;
> > +	int tier = -1;
> > +	DEFINE_MIN_SEQ(lruvec);
> > +
> > +	VM_BUG_ON(!seq_is_valid(lruvec));
> > +
> > +	/*
> > +	 * Try to make the obvious choice first. When anon and file are both
> > +	 * available from the same generation, interpret swappiness 1 as file
> > +	 * first and 200 as anon first.
> > +	 */
> > +	if (!swappiness)
> > +		type = 1;
> > +	else if (min_seq[0] < min_seq[1])
> > +		type = 0;
> > +	else if (swappiness == 1)
> > +		type = 1;
> > +	else if (swappiness == 200)
> > +		type = 0;
> > +	else
> > +		type = get_type_to_scan(lruvec, swappiness, &tier);
> > +
> 
> Wondering wether it will make it simpler to use
> #define ANON 0
> #define FILE 1
> 
> and then
> 	else if (min_seq[ANON] < min_seq[FILE])
> 		type = ANON;
> 
> The usage of 0/1 across code do confuse

I agree, and I plan to do this later because the existing code uses
this convention and needs renaming too.