Re: [RFC PATCH 1/1] zram: Allow rw_page when page isn't written back.

[Brian Geffon]

Thanks Sergey,

On Mon, Aug 8, 2022 at 9:38 PM Sergey Senozhatsky
<senozhatsky@xxxxxxxxxxxx> wrote:
>
> On (22/08/08 12:50), Brian Geffon wrote:
> [..]
> >
> >       pr_info("setup backing device %s\n", file_name);
> > @@ -722,7 +707,8 @@ static ssize_t writeback_store(struct device *dev,
> >
> >               if (zram_test_flag(zram, index, ZRAM_WB) ||
> >                               zram_test_flag(zram, index, ZRAM_SAME) ||
> > -                             zram_test_flag(zram, index, ZRAM_UNDER_WB))
> > +                             zram_test_flag(zram, index, ZRAM_UNDER_WB) ||
> > +                             zram_test_flag(zram, index, ZRAM_NO_WB))
> >                       goto next;
>
> mark_idle() probably should also test ZRAM_NO_WB bit.

While we definitely can add that check in mark_idle() it actually
doesn't hurt to allow marking the page as idle as NO_WB only controls
the writeback aspect and as long as the page is marked NO_WB it won't
be written back, idle or not. Definitely happy to add it in later
versions if people like this approach in general.