Re: [PATCH 1/2] mm/MADV_COLLAPSE: set EAGAIN on unexpected page refcount

From: Hugh Dickins
Date: Thu Feb 09 2023 - 16:50:43 EST


On Thu, 9 Feb 2023, Andrew Morton wrote:
>
> Thanks, I'll merge [1/2] into mm-hotfixes.

Great, thanks.

>
> I'm not seeing anything in the [1/2] changelog which indicates that a
> backport is needed. IOW,

Correct: it's just changing the errno for some racy cases from "you're
wrong, don't bother me again" to "it might be worth having another go":
not fixing an instability, as 2/2 was.

>
> # cat .signature
> When fixing a bug, please describe the end-user visible effects of that bug.

If whatever's being run by the end-user is coded to try again on -EAGAIN,
then the end-user will less often see occasional unexplained failures.

Hugh