Messages in this thread | | | Subject | Re: [PATCH] null_blk: Register as a LightNVM device | From | Jens Axboe <> | Date | Wed, 11 Nov 2015 14:27:34 -0700 |
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On 11/11/2015 03:06 AM, Matias Bjørling wrote: > Add support for registering as a LightNVM device. This allows us to > evaluate the performance of the LightNVM library. > > In /drivers/Makefile, LightNVM is moved above block device drivers > to make sure that the LightNVM media managers have been initialized > before drivers under /drivers/block are initialized.
Generally looks ok. One question:
> +static void *null_lnvm_create_dma_pool(struct request_queue *q, char *name) > +{ > + mempool_t *virtmem_pool; > + > + ppa_cache = kmem_cache_create(name, PAGE_SIZE, 0, 0, NULL); > + if (!ppa_cache) { > + pr_err("null_nvm: Unable to create kmem cache\n"); > + return NULL; > + } > + > + virtmem_pool = mempool_create_slab_pool(64, ppa_cache); > + if (!virtmem_pool) { > + pr_err("null_nvm: Unable to create virtual memory pool\n"); > + return NULL; > + } > + > + return virtmem_pool; > +}
Why create a slab cache if it's pages? Why not just have the mempool alloc/free alloc single pages?
-- Jens Axboe
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