On 8/22/25 18:56, Suren Baghdasaryan wrote:
>> @@ -270,6 +276,84 @@ __kmem_cache_create_args(const char *name, unsigned int
>> size,
>> return ret;
>> }
>>
>> +struct slab_sheaf *
>> +kmem_cache_prefill_sheaf(struct kmem_cache *s, gfp_t gfp, unsigned int size)
>> +{
>> + struct slab_sheaf *sheaf;
>> + unsigned int capacity;
>> +
>> + if (size > s->sheaf_capacity)
>> + capacity = size;
>> + else
>> + capacity = s->sheaf_capacity;
>
> nit:
> capacity = max(size, s->sheaf_capacity);
OK
>> +
>> + sheaf = malloc(sizeof(*sheaf) + sizeof(void *) * s->sheaf_capacity *
>> capacity);
>
> Should this really be `sizeof(void *) * s->sheaf_capacity * capacity`
> or just `sizeof(void *) * capacity` ?
Right, so the whole thing should be:
sizeof(*sheaf) + sizeof(void *) * capacity
>
>> + if (!sheaf) {
>> + return NULL;
>> + }
>> +
>> + memset(sheaf, 0, size);
This is also wrong, so I'm changing it to calloc(1, ...) to get the zeroing
there.
>> + sheaf->cache = s;
>> + sheaf->capacity = capacity;
>> + sheaf->size = kmem_cache_alloc_bulk(s, gfp, size, sheaf->objects);
>> + if (!sheaf->size) {
>> + free(sheaf);
>> + return NULL;
>> + }
>> +
>> + return sheaf;
>> +}
>> +
>> +int kmem_cache_refill_sheaf(struct kmem_cache *s, gfp_t gfp,
>> + struct slab_sheaf **sheafp, unsigned int size)
>> +{
>> + struct slab_sheaf *sheaf = *sheafp;
>> + int refill;
>> +
>> + if (sheaf->size >= size)
>> + return 0;
>> +
>> + if (size > sheaf->capacity) {
>> + sheaf = kmem_cache_prefill_sheaf(s, gfp, size);
>> + if (!sheaf)
>> + return -ENOMEM;
>> +
>> + kmem_cache_return_sheaf(s, gfp, *sheafp);
>> + *sheafp = sheaf;
>> + return 0;
>> + }
>> +
>> + refill = kmem_cache_alloc_bulk(s, gfp, size - sheaf->size,
>> + &sheaf->objects[sheaf->size]);
>> + if (!refill)
>> + return -ENOMEM;
>> +
>> + sheaf->size += refill;
>> + return 0;
>> +}
>> +
>> +void kmem_cache_return_sheaf(struct kmem_cache *s, gfp_t gfp,
>> + struct slab_sheaf *sheaf)
>> +{
>> + if (sheaf->size) {
>> + //s->non_kernel += sheaf->size;
>
> Above comment seems obsolete.
Ack.
>
>> + kmem_cache_free_bulk(s, sheaf->size, &sheaf->objects[0]);
>> + }
>> + free(sheaf);
>> +}
>> +
>> +void *
>> +kmem_cache_alloc_from_sheaf(struct kmem_cache *s, gfp_t gfp,
>> + struct slab_sheaf *sheaf)
>> +{
>> + if (sheaf->size == 0) {
>> + printf("Nothing left in sheaf!\n");
>> + return NULL;
>> + }
>> +
>
> Should we clear sheaf->objects[sheaf->size] for additional safety?
OK.
>> + return sheaf->objects[--sheaf->size];
>> +}
>> +
>> /*
>> * Test the test infrastructure for kem_cache_alloc/free and bulk
>> counterparts.
>> */
>>
>> --
>> 2.50.1
>>
