Re: [RFC PATCH 3/9] mm: zswap: refactor limit checking from zswap_store()

Yosry Ahmed
2024-03-27T22:31:19Z

On Tue, Mar 26, 2024 at 7:42 PM Chengming Zhou <chengming.zhou@linux.dev> wrote:
>
> On 2024/3/26 07:50, Yosry Ahmed wrote:
> > Refactor limit and acceptance threshold checking outside of
> > zswap_store(). This code will be moved around in a following patch, so
> > it would be cleaner to move a function call around.
> >
> > Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
> > ---
> > mm/zswap.c | 32 ++++++++++++++++----------------
> > 1 file changed, 16 insertions(+), 16 deletions(-)
> >
> > diff --git a/mm/zswap.c b/mm/zswap.c
> > index ff1975afb7e3d..6b890c8590ef7 100644
> > --- a/mm/zswap.c
> > +++ b/mm/zswap.c
> > @@ -1415,6 +1415,21 @@ static void zswap_fill_page(void *ptr, unsigned long value)
> > memset_l(page, value, PAGE_SIZE / sizeof(unsigned long));
> > }
> >
> > +static bool zswap_check_limit(void)
> > +{
> > + unsigned long cur_pages = zswap_total_pages();
> > + unsigned long thr = zswap_accept_thr_pages();
> > + unsigned long max_pages = zswap_max_pages();
> > +
> > + if (cur_pages >= max_pages) {
> > + zswap_pool_limit_hit++;
> > + zswap_pool_reached_full = true;
> > + } else if (zswap_pool_reached_full && cur_pages <= thr) {
> > + zswap_pool_reached_full = false;
> > + }
> > + return !zswap_pool_reached_full;
>
> nit: Then we use "!zswap_check_limit()" below, double negation looks complex,
> should we change to zswap_should_reject() or something?

Good point. Will rename it in the next version.

Thanks!