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Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig index 82b84e5ee30d..8b9ffe236e4f 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1752,6 +1752,30 @@ config SLAB_FREELIST_HARDENED sacrifies to harden the kernel slab allocator against common freelist exploit methods. +config SHUFFLE_PAGE_ALLOCATOR + bool "Page allocator randomization" + default SLAB_FREELIST_RANDOM && ACPI_NUMA + help + Randomization of the page allocator improves the average + utilization of a direct-mapped memory-side-cache. See section + 5.2.27 Heterogeneous Memory Attribute Table (HMAT) in the ACPI + 6.2a specification for an example of how a platform advertises + the presence of a memory-side-cache. There are also incidental + security benefits as it reduces the predictability of page + allocations to compliment SLAB_FREELIST_RANDOM, but the + default granularity of shuffling on the "MAX_ORDER - 1" i.e, + 10th order of pages is selected based on cache utilization + benefits on x86. + + While the randomization improves cache utilization it may + negatively impact workloads on platforms without a cache. For + this reason, by default, the randomization is enabled only + after runtime detection of a direct-mapped memory-side-cache. + Otherwise, the randomization may be force enabled with the + 'page_alloc.shuffle' kernel command line parameter. + + Say Y if unsure. + config SLUB_CPU_PARTIAL default y depends on SLUB && SMP |