linux-kernel - Re: [PATCH v4 1/2] mm: store zero pages to be swapped out in a bitmap

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Message-ID: <CAJD7tkaiRZ0fbPRV31bG6fnHPb2NAj_pixF1yFuyuGzsTA6zog@mail.gmail.com>
Date: Thu, 5 Sep 2024 12:28:10 -0700
From: Yosry Ahmed <yosryahmed@...gle.com>
To: Barry Song <21cnbao@...il.com>
Cc: usamaarif642@...il.com, akpm@...ux-foundation.org, 
	chengming.zhou@...ux.dev, david@...hat.com, hannes@...xchg.org, 
	hughd@...gle.com, kernel-team@...a.com, linux-kernel@...r.kernel.org, 
	linux-mm@...ck.org, nphamcs@...il.com, shakeel.butt@...ux.dev, 
	willy@...radead.org, ying.huang@...el.com, hanchuanhua@...o.com
Subject: Re: [PATCH v4 1/2] mm: store zero pages to be swapped out in a bitmap

[..]
> /*
>  * Check if all entries have consistent zeromap status, return true if
>  * all entries are zeromap or non-zeromap, else return false;
>  */
> static inline bool swap_zeromap_entries_check(swp_entry_t entry, int nr)

Let's also rename this now to swap_zeromap_entries_same(), "check" is
a little vague.

> {
>         struct swap_info_struct *sis = swp_swap_info(entry);
>         unsigned long start = swp_offset(entry);
>         unsigned long end = start + *nr;
>
>         if (find_next_bit(sis->zeromap, end, start) == end)
>                 return true;
>         if (find_next_zero_bit(sis->zeromap, end, start) == end)
>                 return true;
>
>         return false;
> }
>