Re: [PATCH v2] zram: fix idle age_sec underflow in idle_store()

[Sergey Senozhatsky]

On (26/08/28 10:24), Andrew Morton wrote:
> On Fri, 28 Aug 2026 16:31:49 +0800 Hao Jia <jiahao.kernel@xxxxxxxxx> wrote:
[..]
> 
> Thanks.  Sashiko asked a couple of questions about this change:
> 	https://sashiko.dev/#/patchset/20260828083149.45760-1-jiahao.kernel@xxxxxxxxx


> Does this early return prevent marking valid boot-time pages as idle?
> When a page is accessed during the first second of system boot, its ac_time
> would be 0.

There is no possibility for zram to hold pages during first second of
system boot, regardless of whether zram was configured as a swap device
or as a block device (mount-ed with real filesystem).


> Can the early return above bypass this zram device initialization check?

We already do that, e.g. when kstrtouint(buf, 0, &age_sec) fails.  Apart
from that, that's not how one checks if device was initialized.  We may
want to consolidate those checks, just for symmetry.