Re: [dpdk-dev] [PATCH v3 07/10] eal: extract common code for memseg list initialization

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 14-Apr-20 8:44 PM, Dmitry Kozlyuk wrote:
> All supported OS create memory segment lists (MSL) and reserve VA space
> for them in a nearly identical way. Move common code into EAL private
> functions to reduce duplication.
> 
> Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> ---
>   lib/librte_eal/common/eal_common_memory.c | 54 ++++++++++++++++++
>   lib/librte_eal/common/eal_private.h       | 34 ++++++++++++
>   lib/librte_eal/freebsd/eal_memory.c       | 54 +++---------------
>   lib/librte_eal/linux/eal_memory.c         | 68 +++++------------------
>   4 files changed, 110 insertions(+), 100 deletions(-)
> 
> diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
> index cc7d54e0c..d9764681a 100644
> --- a/lib/librte_eal/common/eal_common_memory.c
> +++ b/lib/librte_eal/common/eal_common_memory.c
> @@ -25,6 +25,7 @@
>   #include "eal_private.h"
>   #include "eal_internal_cfg.h"
>   #include "eal_memcfg.h"
> +#include "eal_options.h"
>   #include "malloc_heap.h"
>   
>   /*
> @@ -182,6 +183,59 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
>   	return aligned_addr;
>   }
>   
> +int
> +eal_reserve_memseg_list(struct rte_memseg_list *msl,
> +		enum eal_mem_reserve_flags flags)

This and other similar places in this and other patches: i don't think 
using enums for this purpose (i.e. to hold multiple values at once) is 
good practice. I would suggest replacing with int.

Also, i don't think "eal_reserve_memseg_list" is a particularly good or 
descriptive name (and neither is "eal_alloc_memseg_list" for that 
matter). Suggestion: "eal_memseg_list_create" (or "_init") and 
"eal_memseg_list_alloc"?

> +{
> +	uint64_t page_sz;
> +	size_t mem_sz;
> +	void *addr;
> +
> +	page_sz = msl->page_sz;
> +	mem_sz = page_sz * msl->memseg_arr.len;
> +
> +	addr = eal_get_virtual_area(msl->base_va, &mem_sz, page_sz, 0, flags);
> +	if (addr == NULL) {
> +		if (rte_errno == EADDRNOTAVAIL)
> +			RTE_LOG(ERR, EAL, "Cannot reserve %llu bytes at [%p] - "
> +				"please use '--" OPT_BASE_VIRTADDR "' option\n",
> +				(unsigned long long)mem_sz, msl->base_va);
> +		else
> +			RTE_LOG(ERR, EAL, "Cannot reserve memory\n");
> +		return -1;
> +	}
> +	msl->base_va = addr;
> +	msl->len = mem_sz;
> +
> +	return 0;
> +}
> +
> +int
> +eal_alloc_memseg_list(struct rte_memseg_list *msl, uint64_t page_sz,
> +		int n_segs, int socket_id, int type_msl_idx, bool heap)
> +{
> +	char name[RTE_FBARRAY_NAME_LEN];
> +
> +	snprintf(name, sizeof(name), MEMSEG_LIST_FMT, page_sz >> 10, socket_id,
> +		 type_msl_idx);
> +	if (rte_fbarray_init(&msl->memseg_arr, name, n_segs,
> +			sizeof(struct rte_memseg))) {
> +		RTE_LOG(ERR, EAL, "Cannot allocate memseg list: %s\n",
> +			rte_strerror(rte_errno));
> +		return -1;
> +	}
> +
> +	msl->page_sz = page_sz;
> +	msl->socket_id = socket_id;
> +	msl->base_va = NULL;

It probably needs to be documented that eal_alloc_memseg_list must be 
called before eal_reserve_memseg_list.

> +	msl->heap = heap;
> +
> +	RTE_LOG(DEBUG, EAL, "Memseg list allocated: 0x%zxkB at socket %i\n",
> +			(size_t)page_sz >> 10, socket_id);
> +
> +	return 0;
> +}
> +
>   static struct rte_memseg *
>   virt2memseg(const void *addr, const struct rte_memseg_list *msl)
>   {

-- 
Thanks,
Anatoly