[dpdk-stable] [PATCH v7 1/1] fbarray: fix duplicated fbarray file in secondary

[Ananyev, Konstantin]

> -----Original Message-----
> From: yasufum.o at gmail.com <yasufum.o at gmail.com>
> Sent: Wednesday, November 13, 2019 9:44 PM
> To: Burakov, Anatoly <anatoly.burakov at intel.com>; david.marchand at redhat.com; Ananyev, Konstantin <konstantin.ananyev at intel.com>
> Cc: dev at dpdk.org; stable at dpdk.org; yasufum.o at gmail.com; Yasufumi Ogawa <ogawa.yasufumi at lab.ntt.co.jp>
> Subject: [PATCH v7 1/1] fbarray: fix duplicated fbarray file in secondary
> 
> From: Yasufumi Ogawa <ogawa.yasufumi at lab.ntt.co.jp>
> 
> In secondary_msl_create_walk(), it creates a file for fbarrays with its
> PID for reserving unique name among secondary processes. However, it
> does not work if several secondaries run as app containers because each
> of containerized secondary has PID 1, and failed to reserve unique name
> other than first one. To reserve unique name in each of containers, use
> hostname in addition to PID.
> 
> Cc: stable at dpdk.org
> 
> Signed-off-by: Yasufumi Ogawa <yasufum.o at gmail.com>
> ---
>  lib/librte_eal/linux/eal/eal_memalloc.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/librte_eal/linux/eal/eal_memalloc.c b/lib/librte_eal/linux/eal/eal_memalloc.c
> index af6d0d023..11de6d4d6 100644
> --- a/lib/librte_eal/linux/eal/eal_memalloc.c
> +++ b/lib/librte_eal/linux/eal/eal_memalloc.c
> @@ -1365,6 +1365,12 @@ secondary_msl_create_walk(const struct rte_memseg_list *msl,
>  	struct rte_memseg_list *primary_msl, *local_msl;
>  	char name[PATH_MAX];
>  	int msl_idx, ret;
> +	char hostname[HOST_NAME_MAX+1] = { 0 };
> +	/* filename of secondary's fbarray is defined such as
> +	 * "fbarray_memseg-1048576k-0-0_PID_HOSTNAME" and length of PID
> +	 * can be 7 digits maximumly.
> +	 */
> +	int fbarray_sec_name_len = 32 + 7 + 1 + HOST_NAME_MAX + 1;

Not sure, why do we need this calculation at all?
Konstantin


> 
>  	if (msl->external)
>  		return 0;
> @@ -1373,9 +1379,13 @@ secondary_msl_create_walk(const struct rte_memseg_list *msl,
>  	primary_msl = &mcfg->memsegs[msl_idx];
>  	local_msl = &local_memsegs[msl_idx];
> 
> -	/* create distinct fbarrays for each secondary */
> -	snprintf(name, RTE_FBARRAY_NAME_LEN, "%s_%i",
> -		primary_msl->memseg_arr.name, getpid());
> +	/* Create distinct fbarrays for each secondary by using PID and
> +	 * hostname. The reason why using hostname is because PID could be
> +	 * duplicated among secondaries if it is launched in a container.
> +	 */
> +	gethostname(hostname, sizeof(hostname));
> +	snprintf(name, fbarray_sec_name_len, "%s_%d_%s",
> +			primary_msl->memseg_arr.name, (int)getpid(), hostname);
> 
>  	ret = rte_fbarray_init(&local_msl->memseg_arr, name,
>  		primary_msl->memseg_arr.len,
> --
> 2.17.1