[dpdk-stable] [PATCH 2/2] eal/freebsd: add config reattach

[David Marchand]

On Tue, Jun 25, 2019 at 5:51 PM Anatoly Burakov <anatoly.burakov at intel.com>
wrote:

> Linux EAL will attach the shared config at an arbitrary address,
> find out where the shared config is mapped in the primary, and
> then will reattach it at that exact address.
>
> FreeBSD version doesn't seem to go for that extra reattach step,
> which makes one wonder how did it ever work in the first place.
>
> Fix the FreeBSD init to also reattach shared config to the exact
> same place the primary process has it.
>
> Fixes: 764bf26873b9 ("add FreeBSD support")
> Cc: bruce.richardson at intel.com
> Cc: stable at dpdk.org
>
> Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
> ---
>  lib/librte_eal/freebsd/eal/eal.c | 36 ++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
>
> diff --git a/lib/librte_eal/freebsd/eal/eal.c
> b/lib/librte_eal/freebsd/eal/eal.c
> index 8c399c799..ce7a5f91d 100644
> --- a/lib/librte_eal/freebsd/eal/eal.c
> +++ b/lib/librte_eal/freebsd/eal/eal.c
> @@ -280,6 +280,41 @@ rte_eal_config_attach(void)
>         rte_config.mem_config = rte_mem_cfg_addr;
>  }
>
> +/* reattach the shared config at exact memory location primary process
> has it */
> +static void
> +rte_eal_config_reattach(void)
> +{
> +       struct rte_mem_config *mem_config;
> +       void *rte_mem_cfg_addr;
> +
> +       if (internal_config.no_shconf)
> +               return;
> +
> +       /* save the address primary process has mapped shared config to */
> +       rte_mem_cfg_addr =
> +                       (void
> *)(uintptr_t)rte_config.mem_config->mem_cfg_addr;
>

It should be within the 80 columns limit on a single line.

+
> +       /* unmap original config */
> +       munmap(rte_config.mem_config, sizeof(struct rte_mem_config));
>

Hum, the previous mapping is PROT_WRITE while unneeded, right?


+
> +       /* remap the config at proper address */
> +       mem_config = (struct rte_mem_config *) mmap(rte_mem_cfg_addr,
> +                       sizeof(*mem_config), PROT_READ | PROT_WRITE,
> MAP_SHARED,
> +                       mem_cfg_fd, 0);
>

mem_cfg_fd should have been closed in rte_eal_config_attach().
So it should fail here.


+       if (mem_config == MAP_FAILED || mem_config != rte_mem_cfg_addr) {
> +               if (mem_config != MAP_FAILED)
> +                       /* errno is stale, don't use */
> +                       rte_panic("Cannot mmap memory for rte_config at
> [%p], got [%p]\n",
> +                                 rte_mem_cfg_addr, mem_config);
> +               else
> +                       rte_panic("Cannot mmap memory for rte_config!
> error %i (%s)\n",
> +                                 errno, strerror(errno));
> +       }
> +       close(mem_cfg_fd);
> +
> +       rte_config.mem_config = mem_config;
> +}
> +
>  /* Detect if we are a primary or a secondary process */
>  enum rte_proc_type_t
>  eal_proc_type_detect(void)
> @@ -318,6 +353,7 @@ rte_config_init(void)
>         case RTE_PROC_SECONDARY:
>                 rte_eal_config_attach();
>                 rte_eal_mcfg_wait_complete(rte_config.mem_config);
> +               rte_eal_config_reattach();
>                 break;
>         case RTE_PROC_AUTO:
>         case RTE_PROC_INVALID:
> --
> 2.17.1
>


Is there a reason why FreeBSD EAL does not support the virtaddr hint like
for Linux EAL?


-- 
David Marchand