Re: [PATCH v2 2/3] mm/memory-failure: add panic_on_unrecoverable_memory_failure sysctl

[Breno Leitao <leitao@debian.org>]

On Tue, Apr 07, 2026 at 10:57:36AM +0800, Miaohe Lin wrote:
> On 2026/3/31 19:00, Breno Leitao wrote:
> > +	if (sysctl_panic_on_unrecoverable_mf && result == MF_IGNORED &&
> > +	    (type == MF_MSG_KERNEL || type == MF_MSG_KERNEL_HIGH_ORDER ||
> > +	     type == MF_MSG_UNKNOWN))
> > +		panic("Memory failure: %#lx: unrecoverable page", pfn);
> 
> Will it be better to add a helper here?

Yes, a helper would make things easier to read and digest. Thanks for
the feedback. This is what I have in mind:

commit 36d5b3cbbe6d6abfe3296b7b21135a5f01e743eb
Author: Breno Leitao <leitao@debian.org>
Date:   Mon Mar 23 08:00:29 2026 -0700

    mm/memory-failure: add panic_on_unrecoverable_memory_failure sysctl
    
    Add a sysctl that allows the system to panic when an unrecoverable
    memory failure is detected. This covers kernel pages, high-order
    kernel pages, and unknown page types that cannot be recovered.
    
    Signed-off-by: Breno Leitao <leitao@debian.org>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 6ff80e01b91a4..a29b6688fe2d3 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -74,6 +74,8 @@ static int sysctl_memory_failure_recovery __read_mostly = 1;
 
 static int sysctl_enable_soft_offline __read_mostly = 1;
 
+static int sysctl_panic_on_unrecoverable_mf __read_mostly;
+
 atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0);
 
 static bool hw_memory_failure __read_mostly = false;
@@ -155,6 +157,15 @@ static const struct ctl_table memory_failure_table[] = {
 		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_ONE,
+	},
+	{
+		.procname	= "panic_on_unrecoverable_memory_failure",
+		.data		= &sysctl_panic_on_unrecoverable_mf,
+		.maxlen		= sizeof(sysctl_panic_on_unrecoverable_mf),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
 	}
 };
 
@@ -1281,6 +1292,16 @@ static void update_per_node_mf_stats(unsigned long pfn,
 	++mf_stats->total;
 }
 
+static bool is_unrecoverable_memory_failure(enum mf_action_page_type type,
+					    enum mf_result result)
+{
+	return sysctl_panic_on_unrecoverable_mf &&
+	       result == MF_IGNORED &&
+	       (type == MF_MSG_KERNEL ||
+		type == MF_MSG_KERNEL_HIGH_ORDER ||
+		type == MF_MSG_UNKNOWN);
+}
+
 /*
  * "Dirty/Clean" indication is not 100% accurate due to the possibility of
  * setting PG_dirty outside page lock. See also comment above set_page_dirty().
@@ -1298,6 +1319,9 @@ static int action_result(unsigned long pfn, enum mf_action_page_type type,
 	pr_err("%#lx: recovery action for %s: %s\n",
 		pfn, action_page_types[type], action_name[result]);
 
+	if (is_unrecoverable_memory_failure(type, result))
+		panic("Memory failure: %#lx: unrecoverable page", pfn);
+
 	return (result == MF_RECOVERED || result == MF_DELAYED) ? 0 : -EBUSY;
 }