2021-08-03 12:01 (UTC-0700), Narcisa Ana Maria Vasile:
> From: Narcisa Vasile <navas...@microsoft.com>
>
> Allow the user to choose the thread priority through an EAL
> command line argument.
EAL options documentation update is needed.
With current wording the user may ask: the priority of which thread?
> The user can choose thread priority through an EAL parameter,
> when starting an application. If EAL parameter is not used,
> the per-platform default value for thread priority is used.
> Otherwise administrator has an option to set one of available options:
> --thread-prio normal
> --thread-prio realtime
>
> Example:
> ./dpdk-l2fwd -l 0-3 -n 4 --thread-prio normal -- -q 8 -p ffff
IIUC, with this patch --thread-prio affects nothing,
because the value it fills is not used anywhere.
Why is it needed in this patchset then?
>
> Signed-off-by: Narcisa Vasile <navas...@microsoft.com>
> ---
> lib/eal/common/eal_common_options.c | 28 +++++++++++++++++++++++++++-
> lib/eal/common/eal_internal_cfg.h | 2 ++
> lib/eal/common/eal_options.h | 2 ++
> 3 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/lib/eal/common/eal_common_options.c
> b/lib/eal/common/eal_common_options.c
> index ff5861b5f3..9d29696b84 100644
> --- a/lib/eal/common/eal_common_options.c
> +++ b/lib/eal/common/eal_common_options.c
> @@ -107,6 +107,7 @@ eal_long_options[] = {
> {OPT_TELEMETRY, 0, NULL, OPT_TELEMETRY_NUM },
> {OPT_NO_TELEMETRY, 0, NULL, OPT_NO_TELEMETRY_NUM },
> {OPT_FORCE_MAX_SIMD_BITWIDTH, 1, NULL, OPT_FORCE_MAX_SIMD_BITWIDTH_NUM},
> + {OPT_THREAD_PRIORITY, 1, NULL, OPT_THREAD_PRIORITY_NUM},
>
> /* legacy options that will be removed in future */
> {OPT_PCI_BLACKLIST, 1, NULL, OPT_PCI_BLACKLIST_NUM },
> @@ -1412,6 +1413,24 @@ eal_parse_simd_bitwidth(const char *arg)
> return 0;
> }
>
> +static int
> +eal_parse_thread_priority(const char *arg)
> +{
> + struct internal_config *internal_conf =
> + eal_get_internal_configuration();
> + enum rte_thread_priority priority;
> +
> + if (!strncmp("normal", arg, sizeof("normal")))
> + priority = RTE_THREAD_PRIORITY_NORMAL;
> + else if (!strncmp("realtime", arg, sizeof("realtime")))
> + priority = RTE_THREAD_PRIORITY_REALTIME_CRITICAL;
> + else
> + return -1;
Why not just `strcmp()`?
> +
> + internal_conf->thread_priority = priority;
> + return 0;
> +}
> +
> static int
> eal_parse_base_virtaddr(const char *arg)
> {
> @@ -1825,7 +1844,13 @@ eal_parse_common_option(int opt, const char *optarg,
> return -1;
> }
> break;
> -
> + case OPT_THREAD_PRIORITY_NUM:
> + if (eal_parse_thread_priority(optarg) < 0) {
> + RTE_LOG(ERR, EAL, "invalid parameter for --"
> + OPT_THREAD_PRIORITY "\n");
> + return -1;
> + }
> + break;
> /* don't know what to do, leave this to caller */
> default:
> return 1;
> @@ -2088,6 +2113,7 @@ eal_common_usage(void)
> " (can be used multiple times)\n"
> " --"OPT_VMWARE_TSC_MAP" Use VMware TSC map instead of
> native RDTSC\n"
> " --"OPT_PROC_TYPE" Type of this process
> (primary|secondary|auto)\n"
> + " --"OPT_THREAD_PRIORITY" Set threads priority
> (normal|realtime)\n"
> #ifndef RTE_EXEC_ENV_WINDOWS
> " --"OPT_SYSLOG" Set syslog facility\n"
> #endif
> diff --git a/lib/eal/common/eal_internal_cfg.h
> b/lib/eal/common/eal_internal_cfg.h
> index d6c0470eb8..b2996cd65b 100644
> --- a/lib/eal/common/eal_internal_cfg.h
> +++ b/lib/eal/common/eal_internal_cfg.h
> @@ -94,6 +94,8 @@ struct internal_config {
> unsigned int no_telemetry; /**< true to disable Telemetry */
> struct simd_bitwidth max_simd_bitwidth;
> /**< max simd bitwidth path to use */
> + enum rte_thread_priority thread_priority;
> + /**< thread priority to configure */
Where is the default set?
If you remove RTE_THREAD_PRIORITY_UNDEFINED in patch 2/10,
it will be RTE_THREAD_PRIORITY_NORMAL in zeroed-out structure, which is OK.
> };
>
> void eal_reset_internal_config(struct internal_config *internal_cfg);
> diff --git a/lib/eal/common/eal_options.h b/lib/eal/common/eal_options.h
> index 7b348e707f..9f5b209f64 100644
> --- a/lib/eal/common/eal_options.h
> +++ b/lib/eal/common/eal_options.h
> @@ -93,6 +93,8 @@ enum {
> OPT_NO_TELEMETRY_NUM,
> #define OPT_FORCE_MAX_SIMD_BITWIDTH "force-max-simd-bitwidth"
> OPT_FORCE_MAX_SIMD_BITWIDTH_NUM,
> +#define OPT_THREAD_PRIORITY "thread-prio"
> + OPT_THREAD_PRIORITY_NUM,
>
> /* legacy option that will be removed in future */
> #define OPT_PCI_BLACKLIST "pci-blacklist"
