Re: [dpdk-dev] [PATCH v3 6/9] memalloc: add EAL-internal API to get and set segment fd's

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 09/04/2018 05:15 PM, Anatoly Burakov wrote:
> Enable setting and retrieving segment fd's internally.
> 
> For now, retrieving fd's will not be used anywhere until we
> get an external API, but it will be useful for things like
> virtio, where we wish to share segment fd's.
> 
> Setting segment fd's will not be available as a public API
> at this time, but internally it is needed for legacy mode,
> because we're not allocating our hugepages in memalloc in
> legacy mode case, and we still need to store the fd.
> 
> Another user of get segment fd API is memseg info dump, to
> show which pages use which fd's.
> 
> Not supported on FreeBSD.
> 
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> ---
>   lib/librte_eal/bsdapp/eal/eal_memalloc.c   | 12 +++++
>   lib/librte_eal/common/eal_common_memory.c  |  8 +--
>   lib/librte_eal/common/eal_memalloc.h       |  6 +++
>   lib/librte_eal/linuxapp/eal/eal_memalloc.c | 60 +++++++++++++++++-----
>   lib/librte_eal/linuxapp/eal/eal_memory.c   | 44 +++++++++++++---
>   5 files changed, 109 insertions(+), 21 deletions(-)
> 
> diff --git a/lib/librte_eal/bsdapp/eal/eal_memalloc.c b/lib/librte_eal/bsdapp/eal/eal_memalloc.c
> index f7f07abd6..a5fb09f71 100644
> --- a/lib/librte_eal/bsdapp/eal/eal_memalloc.c
> +++ b/lib/librte_eal/bsdapp/eal/eal_memalloc.c
> @@ -47,6 +47,18 @@ eal_memalloc_sync_with_primary(void)
>   	return -1;
>   }
>   
> +int
> +eal_memalloc_get_seg_fd(int list_idx, int seg_idx)
> +{
> +	return -1;

Why not returning -ENOTSUPP directly here? (see patch 7).

> +}
> +
> +int
> +eal_memalloc_set_seg_fd(int list_idx, int seg_idx, int fd)
> +{
> +	return -1;

Ditto.

> +}
> +

Other than that, the patch looks good to me.

Maxime