Re: [PATCH] zram: add accounting for incompressible pages

[chenqiwu <qiwuchen55@gmail.com>]

On Thu, Apr 16, 2026 at 04:07:59PM +0900, Sergey Senozhatsky wrote:
> On (26/04/15 18:43), qiwu.chen wrote:
> > 1. Rename write_incompressible_page to write_huge_page since huge page
> > could be recompressed with secondary algorithms.
> 
> Please no. "huge_page" is the most confusing term that zram uses.
>
So what is differece between ZRAM_HUGE and ZRAM_INCOMPRESSIBLE?
In my opinion, the slot is marked as ZRAM_HUGE if primary algorithm
cannot compress the page. the slot is marked as ZRAM_INCOMPRESSIBLE
if scondary algorithms failed to recompress the page in a way that
condary algorithms failed to recompress the page.
The huge page could be recompressed with secondary algorithms with
a certain probability, so it should not be defined as incompressible page.
> > 2. Similar to huge page, add incompressible_pages accounting for current
> > incompressible pages, and incompressible_pages_since accounting for
> > incompressible pages since zram set up. The accounting value can be showed
> > by mm_stat.
> 
> What for?
Add accounting for ZRAM_INCOMPRESSIBLE pages showed by mm_stat, so we can get
how many pages is incompressiable in current system.