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| author | Baoquan He <bhe@redhat.com> | 2022-11-13 13:08:27 +0300 |
|---|---|---|
| committer | Vlastimil Babka <vbabka@suse.cz> | 2022-11-21 12:19:25 +0300 |
| commit | e8753e416c7ec39812cf92608aa95640caca70fa (patch) | |
| tree | 634ef58d83d52524cc6307f79b10042e34b56314 /include/linux/percpu.h | |
| parent | a8e53869995b90609a798f9830d44086ab6025c4 (diff) | |
| download | linux-e8753e416c7ec39812cf92608aa95640caca70fa.tar.xz | |
percpu: adjust the value of PERCPU_DYNAMIC_EARLY_SIZE
LKP reported a build failure as below on the following patch "mm/slub,
percpu: correct the calculation of early percpu allocation size"
~~~~~~
In file included from <command-line>:
In function 'alloc_kmem_cache_cpus',
inlined from 'kmem_cache_open' at mm/slub.c:4340:6:
>> >> include/linux/compiler_types.h:357:45: error: call to '__compiletime_assert_474' declared with attribute error:
BUILD_BUG_ON failed: PERCPU_DYNAMIC_EARLY_SIZE < NR_KMALLOC_TYPES * KMALLOC_SHIFT_HIGH * sizeof(struct kmem_cache_cpu)
357 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
~~~~~~
From the kernel config file provided by LKP, the building was made on
arm64 with below Kconfig item enabled:
CONFIG_ZONE_DMA=y
CONFIG_SLUB_CPU_PARTIAL=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_SLUB_STATS=y
CONFIG_ARM64_PAGE_SHIFT=16
CONFIG_ARM64_64K_PAGES=y
Then we will have:
NR_KMALLOC_TYPES:4
KMALLOC_SHIFT_HIGH:17
sizeof(struct kmem_cache_cpu):184
The product of them is 12512, which is bigger than PERCPU_DYNAMIC_EARLY_SIZE,
12K. Hence, the BUILD_BUG_ON in alloc_kmem_cache_cpus() is triggered.
Earlier, in commit 099a19d91ca4 ("percpu: allow limited allocation
before slab is online"), PERCPU_DYNAMIC_EARLY_SIZE was introduced and
set to 12K which is equal to the then PERPCU_DYNAMIC_RESERVE.
Later, in commit 1a4d76076cda ("percpu: implement asynchronous chunk
population"), PERPCU_DYNAMIC_RESERVE was increased by 8K, while
PERCPU_DYNAMIC_EARLY_SIZE was kept unchanged.
So, here increase PERCPU_DYNAMIC_EARLY_SIZE by 8K too to accommodate to
the slub's requirement.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'include/linux/percpu.h')
| -rw-r--r-- | include/linux/percpu.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/percpu.h b/include/linux/percpu.h index f1ec5ad1351c..3dbb6fb70658 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -42,7 +42,7 @@ * larger than PERCPU_DYNAMIC_EARLY_SIZE. */ #define PERCPU_DYNAMIC_EARLY_SLOTS 128 -#define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10) +#define PERCPU_DYNAMIC_EARLY_SIZE (20 << 10) /* * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy |