Re: [PATCH v3] mm/memory-failure: Support disabling soft offline for HugeTLB pages

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 14 Sep 2026 18:49:38 -0500 Kyle Meyer <kyle.meyer@hpe.com> wrote:

> Soft offlining a HugeTLB page dissolves it, permanently reducing the
> HugeTLB page pool. This can be problematic for workloads that depend on
> a fixed number of HugeTLB pages.
> 
> Currently, soft offline must be disabled to prevent HugeTLB pages from
> being soft offlined.
> 
> This patch allows soft offline to be disabled for HugeTLB pages while
> remaining enabled for non-HugeTLB pages.
> 
> Commit 56374430c5dfc ("mm/memory-failure: userspace controls
> soft-offlining pages") introduced the following sysctl interface to
> control soft offline:
> 
> /proc/sys/vm/enable_soft_offline
> 
> The interface does not distinguish between page types:
> 
>     0 - Soft offline is disabled
>     1 - Soft offline is enabled
> 
> Convert enable_soft_offline to a bitmask and support disabling soft
> offline for HugeTLB pages:
> 
> Bits:
> 
>     0 - Enable soft offline
>     1 - Disable soft offline for HugeTLB pages
> 
> Supported values:
> 
>     0 - Soft offline is disabled
>     1 - Soft offline is enabled
>     3 - Soft offline is enabled (disabled for HugeTLB pages)
> 
> Existing behavior is preserved.
> 
> Update documentation and HugeTLB soft offline selftests.

I'm hitting some rejects against
https://lore.kernel.org/20260825085756.63030-4-husong@kylinos.cn. 
Please update this against mm.git's mm-unstalbe branch or linux-next.

I'd updated v2's changelog with this:


Tony said:

: Recap of original problem is that some BIOS keep track of error
: threshold per-rank and use this GHES mechanism to report threshold
: exceeded on the rank.
: 
: Systems that stay up a long time can accumulate enough soft errors to
: trigger this threshold.  But the action of taking a page offline isn't
: going to help.  For a 4K page this is merely annoying.  For 1G page it
: can mess things up badly.
: 
: My original patch for this just skipped the GHES->offline process for
: huge pages.  But I wasn't aware of the sysctl control.  That provides a
: better solution.

Which is cumbersome but I think there's useful info here so please
incorporate in some way.

> Suggested-by: Tony Luck <tony.luck@intel.com>
> Signed-off-by: Kyle Meyer <kyle.meyer@hpe.com>

v2 had

Reported-by: Shawn Fan <shawn.fan@intel.com>

which got lost.