On 4/11/22 13:07, Hyeonggon Yoo wrote:
> On Mon, Apr 11, 2022 at 01:25:11AM +0900, Ohhoon Kwon wrote:
>> There are four types of kmalloc_caches: KMALLOC_NORMAL, KMALLOC_CGROUP,
>> KMALLOC_RECLAIM, and KMALLOC_DMA. While the first three types are
>> created using new_kmalloc_cache(), KMALLOC_DMA caches are created in a
>> separate logic. Let KMALLOC_DMA caches be also created using
>> new_kmalloc_cache(), to enhance readability.
>>
>> Historically, there were only KMALLOC_NORMAL caches and KMALLOC_DMA
>> caches in the first place, and they were initialized in two separate
>> logics. However, when KMALLOC_RECLAIM was introduced in v4.20 via
>> commit 1291523f2c1d ("mm, slab/slub: introduce kmalloc-reclaimable
>> caches") and KMALLOC_CGROUP was introduced in v5.14 via
>> commit 494c1dfe855e ("mm: memcg/slab: create a new set of kmalloc-cg-<n>
>> caches"), their creations were merged with KMALLOC_NORMAL's only.
>> KMALLOC_DMA creation logic should be merged with them, too.
>>
>> By merging KMALLOC_DMA initialization with other types, the following
>> two changes might occur:
>> 1. The order dma-kmalloc-<n> caches added in slab_cache list may be
>> sorted by size. i.e. the order they appear in /proc/slabinfo may change
>> as well.
>> 2. slab_state will be set to UP after KMALLOC_DMA is created.
>> In case of slub, freelist randomization is dependent on slab_state>=UP,
>> and therefore KMALLOC_DMA cache's freelist will not be randomized in
>> creation, but will be deferred to init_freelist_randomization().
>>
>> Co-developed-by: JaeSang Yoo <jsyoo5b@xxxxxxxxx>
>> Signed-off-by: JaeSang Yoo <jsyoo5b@xxxxxxxxx>
>> Signed-off-by: Ohhoon Kwon <ohkwon1043@xxxxxxxxx>
>> ---
>> mm/slab_common.c | 18 +++---------------
>> 1 file changed, 3 insertions(+), 15 deletions(-)
>>
>> diff --git a/mm/slab_common.c b/mm/slab_common.c
>> index 6ee64d6208b3..a959d247c27b 100644
>> --- a/mm/slab_common.c
>> +++ b/mm/slab_common.c
>> @@ -849,6 +849,8 @@ new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
>> return;
>> }
>> flags |= SLAB_ACCOUNT;
>> + } else if (IS_ENABLED(CONFIG_ZONE_DMA) && (type == KMALLOC_DMA)) {
>> + flags |= SLAB_CACHE_DMA;
>> }
>>
>> kmalloc_caches[type][idx] = create_kmalloc_cache(
>> @@ -877,7 +879,7 @@ void __init create_kmalloc_caches(slab_flags_t flags)
>> /*
>> * Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined
>> */
>> - for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) {
>> + for (type = KMALLOC_NORMAL; type < NR_KMALLOC_TYPES; type++) {
>> for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
>> if (!kmalloc_caches[type][i])
>> new_kmalloc_cache(i, type, flags);
>> @@ -898,20 +900,6 @@ void __init create_kmalloc_caches(slab_flags_t flags)
>>
>> /* Kmalloc array is now usable */
>> slab_state = UP;
>> -
>> -#ifdef CONFIG_ZONE_DMA
>> - for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
>> - struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i];
>> -
>> - if (s) {
>> - kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache(
>> - kmalloc_info[i].name[KMALLOC_DMA],
>> - kmalloc_info[i].size,
>> - SLAB_CACHE_DMA | flags, 0,
>> - kmalloc_info[i].size);
>> - }
>> - }
>> -#endif
>> }
>> #endif /* !CONFIG_SLOB */
>>
>
> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
Thanks.
Added to:
https://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab.git/log/?h=for-5.19/refactor
> BTW this patch may conflict with [1] (not merged yet)
>
> [1] https://lore.kernel.org/linux-mm/20220405135758.774016-9-catalin.marinas@xxxxxxx/
FYI Catalin, might want to base v2 on the above once the crypto side is
solved. At cursory look it shouldn't be a significant conflict.
> Thanks!
>
>> --
>> 2.25.1
>>
>
