Document the new vm.panic_on_unrecoverable_memory_failure sysctl in the admin guide, following the same format as panic_on_unrecovered_nmi. Signed-off-by: Breno Leitao --- Documentation/admin-guide/sysctl/vm.rst | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index 97e12359775c..a811f503bca6 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -67,6 +67,7 @@ Currently, these files are in /proc/sys/vm: - page-cluster - page_lock_unfairness - panic_on_oom +- panic_on_unrecoverable_memory_failure - percpu_pagelist_high_fraction - stat_interval - stat_refresh @@ -925,6 +926,32 @@ panic_on_oom=2+kdump gives you very strong tool to investigate why oom happens. You can get snapshot. +panic_on_unrecoverable_memory_failure +====================================== + +When a hardware memory error (e.g. multi-bit ECC) hits an in-use kernel +page that cannot be recovered by the memory failure handler, the default +behaviour is to ignore the error and continue operation. This is +dangerous because the corrupted data remains accessible to the kernel, +risking silent data corruption or a delayed crash when the poisoned +memory is next accessed. + +Pages that reach this path include slab objects (dentry cache, inode +cache, etc.), page tables, kernel stacks, and other kernel allocations +that lack the reverse mapping needed to isolate all references. + +For many environments it is preferable to panic immediately with a clean +crash dump that captures the original error context, rather than to +continue and face a random crash later whose cause is difficult to +diagnose. + += ===================================================================== +0 Try to continue operation (default). +1 Panic immediately. If the ``panic`` sysctl is also non-zero then the + machine will be rebooted. += ===================================================================== + + percpu_pagelist_high_fraction ============================= -- 2.52.0