Re: [PATCH] mem: exclude used memory from core dump by config

[Jerin Jacob <jerinjacobk@gmail.com>]

On Tue, Dec 14, 2021 at 5:12 PM Gaoxiang Liu <gaoxiangliu0@163.com> wrote:
>
> Some DPDK application is allolcateed storage partition of 8G(or smaller)

allocated

> If coredump happens, the application doesn't work because of
> insufficient storage space.
> The patch provides a config that means whether the huge used memory
> needs to be not dumped in core dump.
> The DPDK application can choose to open it according to the actual
> situation.
>
> Fixes: d72e4042c5eb ("mem: exclude unused memory from core dump")
> Cc: stable@dpdk.org

Probably subject can be changed to: eal: allow to exclude memseg from core dump

>
> Signed-off-by: Gaoxiang Liu <liugaoxiang@huawei.com>
> ---
>  lib/eal/common/eal_internal_cfg.h |  1 +
>  lib/eal/common/eal_options.h      |  3 ++-
>  lib/eal/linux/eal.c               |  3 +++
>  lib/eal/linux/eal_memalloc.c      | 10 ++++++++++

freebsd support can be updated,
Please update doc/guides/linux_gsg/linux_eal_parameters.rst and
doc/guides/freebsd_gsg/freebsd_eal_parameters.rst.


>  4 files changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/lib/eal/common/eal_internal_cfg.h b/lib/eal/common/eal_internal_cfg.h
> index d6c0470eb8..f9cd300f86 100644
> --- a/lib/eal/common/eal_internal_cfg.h
> +++ b/lib/eal/common/eal_internal_cfg.h
> @@ -87,6 +87,7 @@ struct internal_config {
>                         /**< user defined mbuf pool ops name */
>         unsigned num_hugepage_sizes;      /**< how many sizes on this system */
>         struct hugepage_info hugepage_info[MAX_HUGEPAGE_SIZES];
> +       volatile unsigned huge_dont_dump_flag;

Volatile may not be needed. it can be changed to bool as well.


>         enum rte_iova_mode iova_mode ;    /**< Set IOVA mode on this system  */
>         rte_cpuset_t ctrl_cpuset;         /**< cpuset for ctrl threads */
>         volatile unsigned int init_complete;
> diff --git a/lib/eal/common/eal_options.h b/lib/eal/common/eal_options.h
> index 8e4f7202a2..6b9a24f0f9 100644
> --- a/lib/eal/common/eal_options.h
> +++ b/lib/eal/common/eal_options.h
> @@ -87,7 +87,8 @@ enum {
>         OPT_NO_TELEMETRY_NUM,
>  #define OPT_FORCE_MAX_SIMD_BITWIDTH  "force-max-simd-bitwidth"
>         OPT_FORCE_MAX_SIMD_BITWIDTH_NUM,
> -
> +#define OPT_HUGE_DONT_DUMP     "huge-dont-dump"
> +       OPT_HUGE_DONT_DUMP_NUM,
>         OPT_LONG_MAX_NUM
>  };
>
> diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
> index 60b4924838..eeab5e4f3d 100644
> --- a/lib/eal/linux/eal.c
> +++ b/lib/eal/linux/eal.c
> @@ -816,6 +816,9 @@ eal_parse_args(int argc, char **argv)
>                 case OPT_MATCH_ALLOCATIONS_NUM:
>                         internal_conf->match_allocations = 1;
>                         break;
> +               case OPT_HUGE_DONT_DUMP_NUM:
> +                       internal_config->huge_dont_dump_flag = 1;
> +                       break;
>
>                 default:
>                         if (opt < OPT_LONG_MIN_NUM && isprint(opt)) {
> diff --git a/lib/eal/linux/eal_memalloc.c b/lib/eal/linux/eal_memalloc.c
> index 337f2bc739..13ca1cf58c 100644
> --- a/lib/eal/linux/eal_memalloc.c
> +++ b/lib/eal/linux/eal_memalloc.c
> @@ -663,6 +663,16 @@ alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
>         ms->iova = iova;
>         ms->socket_id = socket_id;
>
> +       if (internal_config->huge_dont_dump_flag) {
> +               if (madvise(addr, alloc_sz, EAL_DONTDUMP)) {
> +                       RTE_LOG(INFO, EAL, "madvise(%p, %#zx, %d) failed: %s\n",
> +                                       virt, size, flags, strerror(rte_errno));
> +               } else {
> +                       RTE_LOG(INFO, EAL, "%s(): madvise(MADV_DONTDUMP) memory success.(len=%zu)\n",
> +                                       __func__, alloc_sz);
> +               }

I think, you can use eal_mem_set_dump()

> +       }
> +
>         return 0;
>
>  mapped:
> --
> 2.32.0
>
>