linux/arch/arm64
Peter Collingbourne d949a8155d mm: make minimum slab alignment a runtime property
When CONFIG_KASAN_HW_TAGS is enabled we currently increase the minimum
slab alignment to 16.  This happens even if MTE is not supported in
hardware or disabled via kasan=off, which creates an unnecessary memory
overhead in those cases.  Eliminate this overhead by making the minimum
slab alignment a runtime property and only aligning to 16 if KASAN is
enabled at runtime.

On a DragonBoard 845c (non-MTE hardware) with a kernel built with
CONFIG_KASAN_HW_TAGS, waiting for quiescence after a full Android boot I
see the following Slab measurements in /proc/meminfo (median of 3
reboots):

Before: 169020 kB
After:  167304 kB

[akpm@linux-foundation.org: make slab alignment type `unsigned int' to avoid casting]
Link: https://linux-review.googlesource.com/id/I752e725179b43b144153f4b6f584ceb646473ead
Link: https://lkml.kernel.org/r/20220427195820.1716975-2-pcc@google.com
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13 07:20:07 -07:00
..
boot arm64: dts: qcom/sdm845-shift-axolotl: Fix boolean properties with values 2022-04-14 22:52:17 +02:00
configs ARM: DT updates for 5.18 2022-03-23 18:37:22 -07:00
crypto crypto: arm64 - cleanup comments 2022-03-09 15:12:32 +12:00
hyperv
include mm: make minimum slab alignment a runtime property 2022-05-13 07:20:07 -07:00
kernel arm64: Add part number for Arm Cortex-A78AE 2022-04-08 11:46:46 +01:00
kvm KVM: arm64: mixed-width check should be skipped for uninitialized vCPUs 2022-04-06 12:29:45 +01:00
lib Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2022-03-21 16:02:36 -07:00
mm mm: hugetlb_vmemmap: cleanup CONFIG_HUGETLB_PAGE_FREE_VMEMMAP* 2022-04-28 23:16:15 -07:00
net kasan, arm64: don't tag executable vmalloc allocations 2022-03-24 19:06:48 -07:00
tools Merge branch 'for-next/spectre-bhb' into for-next/core 2022-03-14 19:08:31 +00:00
xen xen: allow pv-only hypercalls only with CONFIG_XEN_PV 2021-11-02 08:11:01 -05:00
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig mm: hugetlb_vmemmap: cleanup CONFIG_HUGETLB_PAGE_FREE_VMEMMAP* 2022-04-28 23:16:15 -07:00
Kconfig.debug
Kconfig.platforms ARM: DT updates for 5.18 2022-03-23 18:37:22 -07:00
Makefile arm64/xor: use EOR3 instructions when available 2021-12-14 12:14:26 +00:00