[dpdk-dev] [PATCH v7 01/18] eal: add max SIMD bitwidth
Ciara Power
ciara.power at intel.com
Thu Oct 15 17:22:42 CEST 2020
This patch adds a max SIMD bitwidth EAL configuration. The API allows
for an app to set this value. It can also be set using EAL argument
--force-max-simd-bitwidth, which will lock the value and override any
modifications made by the app.
Each arch has a define for the default SIMD bitwidth value, this is used
on EAL init to set the config max SIMD bitwidth.
Cc: Ruifeng Wang <ruifeng.wang at arm.com>
Cc: Jerin Jacob <jerinj at marvell.com>
Cc: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
Cc: David Christensen <drc at linux.vnet.ibm.com>
Signed-off-by: Ciara Power <ciara.power at intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
---
v7: Reordered entries in the symbol .map file.
v4:
- Used RTE_SIMD_MAX instead of UINT16_MAX.
- Renamed enums to better reflect usage.
- Added functions to windows symbol export file.
- Modified Doxygen comments.
- Modified enum name.
- Changed RTE_SIMD_MAX value to a power of 2.
- Merged patch 2 into this patch.
- Enum now used for default value defines.
- Fixed some small comments on v3.
v3:
- Added enum value to essentially disable using max SIMD to choose
paths, intended for use by ARM SVE.
- Fixed parsing bitwidth argument to return an error for values
greater than uint16_t.
- Removed unnecessary define in generic rte_vect.h
- Changed default bitwidth for ARM to UINT16_MAX, to allow for SVE.
v2:
- Added to Doxygen comment for API.
- Changed default bitwidth for Arm to 128.
---
lib/librte_eal/arm/include/rte_vect.h | 2 +
lib/librte_eal/common/eal_common_options.c | 66 ++++++++++++++++++++++
lib/librte_eal/common/eal_internal_cfg.h | 8 +++
lib/librte_eal/common/eal_options.h | 2 +
lib/librte_eal/include/rte_eal.h | 40 +++++++++++++
lib/librte_eal/ppc/include/rte_vect.h | 2 +
lib/librte_eal/rte_eal_exports.def | 2 +
lib/librte_eal/rte_eal_version.map | 2 +
lib/librte_eal/x86/include/rte_vect.h | 2 +
9 files changed, 126 insertions(+)
diff --git a/lib/librte_eal/arm/include/rte_vect.h b/lib/librte_eal/arm/include/rte_vect.h
index f6a455b4e7..df8fb8b670 100644
--- a/lib/librte_eal/arm/include/rte_vect.h
+++ b/lib/librte_eal/arm/include/rte_vect.h
@@ -14,6 +14,8 @@
extern "C" {
#endif
+#define RTE_DEFAULT_SIMD_BITWIDTH RTE_SIMD_MAX
+
typedef int32x4_t xmm_t;
#define XMM_SIZE (sizeof(xmm_t))
diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index a5426e1234..8c79f1b2fc 100644
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -35,6 +35,7 @@
#ifndef RTE_EXEC_ENV_WINDOWS
#include <rte_telemetry.h>
#endif
+#include <rte_vect.h>
#include "eal_internal_cfg.h"
#include "eal_options.h"
@@ -102,6 +103,7 @@ eal_long_options[] = {
{OPT_MATCH_ALLOCATIONS, 0, NULL, OPT_MATCH_ALLOCATIONS_NUM},
{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},
{0, 0, NULL, 0 }
};
@@ -343,6 +345,8 @@ eal_reset_internal_config(struct internal_config *internal_cfg)
internal_cfg->user_mbuf_pool_ops_name = NULL;
CPU_ZERO(&internal_cfg->ctrl_cpuset);
internal_cfg->init_complete = 0;
+ internal_cfg->max_simd_bitwidth.bitwidth = RTE_DEFAULT_SIMD_BITWIDTH;
+ internal_cfg->max_simd_bitwidth.forced = 0;
}
static int
@@ -1309,6 +1313,34 @@ eal_parse_iova_mode(const char *name)
return 0;
}
+static int
+eal_parse_simd_bitwidth(const char *arg)
+{
+ char *end;
+ unsigned long bitwidth;
+ int ret;
+ struct internal_config *internal_conf =
+ eal_get_internal_configuration();
+
+ if (arg == NULL || arg[0] == '\0')
+ return -1;
+
+ errno = 0;
+ bitwidth = strtoul(arg, &end, 0);
+
+ /* check for errors */
+ if (errno != 0 || end == NULL || *end != '\0' || bitwidth > RTE_SIMD_MAX)
+ return -1;
+
+ if (bitwidth == 0)
+ bitwidth = (unsigned long) RTE_SIMD_MAX;
+ ret = rte_set_max_simd_bitwidth(bitwidth);
+ if (ret < 0)
+ return -1;
+ internal_conf->max_simd_bitwidth.forced = 1;
+ return 0;
+}
+
static int
eal_parse_base_virtaddr(const char *arg)
{
@@ -1707,6 +1739,13 @@ eal_parse_common_option(int opt, const char *optarg,
case OPT_NO_TELEMETRY_NUM:
conf->no_telemetry = 1;
break;
+ case OPT_FORCE_MAX_SIMD_BITWIDTH_NUM:
+ if (eal_parse_simd_bitwidth(optarg) < 0) {
+ RTE_LOG(ERR, EAL, "invalid parameter for --"
+ OPT_FORCE_MAX_SIMD_BITWIDTH "\n");
+ return -1;
+ }
+ break;
/* don't know what to do, leave this to caller */
default:
@@ -1903,6 +1942,32 @@ eal_check_common_options(struct internal_config *internal_cfg)
return 0;
}
+uint16_t
+rte_get_max_simd_bitwidth(void)
+{
+ const struct internal_config *internal_conf =
+ eal_get_internal_configuration();
+ return internal_conf->max_simd_bitwidth.bitwidth;
+}
+
+int
+rte_set_max_simd_bitwidth(uint16_t bitwidth)
+{
+ struct internal_config *internal_conf =
+ eal_get_internal_configuration();
+ if (internal_conf->max_simd_bitwidth.forced) {
+ RTE_LOG(NOTICE, EAL, "Cannot set max SIMD bitwidth - user runtime override enabled");
+ return -EPERM;
+ }
+
+ if (bitwidth < RTE_SIMD_DISABLED || !rte_is_power_of_2(bitwidth)) {
+ RTE_LOG(ERR, EAL, "Invalid bitwidth value!\n");
+ return -EINVAL;
+ }
+ internal_conf->max_simd_bitwidth.bitwidth = bitwidth;
+ return 0;
+}
+
void
eal_common_usage(void)
{
@@ -1981,6 +2046,7 @@ eal_common_usage(void)
" --"OPT_BASE_VIRTADDR" Base virtual address\n"
" --"OPT_TELEMETRY" Enable telemetry support (on by default)\n"
" --"OPT_NO_TELEMETRY" Disable telemetry support\n"
+ " --"OPT_FORCE_MAX_SIMD_BITWIDTH" Force the max SIMD bitwidth\n"
"\nEAL options for DEBUG use only:\n"
" --"OPT_HUGE_UNLINK" Unlink hugepage files after init\n"
" --"OPT_NO_HUGE" Use malloc instead of hugetlbfs\n"
diff --git a/lib/librte_eal/common/eal_internal_cfg.h b/lib/librte_eal/common/eal_internal_cfg.h
index de627c7627..51dbe86e2b 100644
--- a/lib/librte_eal/common/eal_internal_cfg.h
+++ b/lib/librte_eal/common/eal_internal_cfg.h
@@ -33,6 +33,12 @@ struct hugepage_info {
int lock_descriptor; /**< file descriptor for hugepage dir */
};
+struct simd_bitwidth {
+ bool forced;
+ /**< flag indicating if bitwidth is forced and can't be modified */
+ uint16_t bitwidth; /**< bitwidth value */
+};
+
/**
* internal configuration
*/
@@ -85,6 +91,8 @@ struct internal_config {
volatile unsigned int init_complete;
/**< indicates whether EAL has completed initialization */
unsigned int no_telemetry; /**< true to disable Telemetry */
+ struct simd_bitwidth max_simd_bitwidth;
+ /**< max simd bitwidth path to use */
};
void eal_reset_internal_config(struct internal_config *internal_cfg);
diff --git a/lib/librte_eal/common/eal_options.h b/lib/librte_eal/common/eal_options.h
index 89769d48b4..ef33979664 100644
--- a/lib/librte_eal/common/eal_options.h
+++ b/lib/librte_eal/common/eal_options.h
@@ -85,6 +85,8 @@ enum {
OPT_TELEMETRY_NUM,
#define OPT_NO_TELEMETRY "no-telemetry"
OPT_NO_TELEMETRY_NUM,
+#define OPT_FORCE_MAX_SIMD_BITWIDTH "force-max-simd-bitwidth"
+ OPT_FORCE_MAX_SIMD_BITWIDTH_NUM,
OPT_LONG_MAX_NUM
};
diff --git a/lib/librte_eal/include/rte_eal.h b/lib/librte_eal/include/rte_eal.h
index e3c2ef185e..706d3cca5a 100644
--- a/lib/librte_eal/include/rte_eal.h
+++ b/lib/librte_eal/include/rte_eal.h
@@ -43,6 +43,23 @@ enum rte_proc_type_t {
RTE_PROC_INVALID
};
+/**
+ * The max SIMD bitwidth value to limit vector path selection.
+ */
+enum rte_max_simd {
+ RTE_SIMD_DISABLED = 64,
+ /**< Limits path selection to scalar, disables all vector paths. */
+ RTE_SIMD_128 = 128,
+ /**< Limits path selection to SSE/NEON/Altivec or below. */
+ RTE_SIMD_256 = 256, /**< Limits path selection to AVX2 or below. */
+ RTE_SIMD_512 = 512, /**< Limits path selection to AVX512 or below. */
+ RTE_SIMD_MAX = INT16_MAX + 1,
+ /**<
+ * Disables limiting by max SIMD bitwidth, allows all suitable paths.
+ * This value is used as it is a large number and a power of 2.
+ */
+};
+
/**
* Get the process type in a multi-process setup
*
@@ -51,6 +68,29 @@ enum rte_proc_type_t {
*/
enum rte_proc_type_t rte_eal_process_type(void);
+/**
+ * Get the supported SIMD bitwidth.
+ *
+ * @return
+ * uint16_t bitwidth.
+ */
+__rte_experimental
+uint16_t rte_get_max_simd_bitwidth(void);
+
+/**
+ * Set the supported SIMD bitwidth.
+ * This API should only be called once at initialization, before EAL init.
+ *
+ * @param bitwidth
+ * uint16_t bitwidth.
+ * @return
+ * - 0 on success.
+ * - -EINVAL on invalid bitwidth parameter.
+ * - -EPERM if bitwidth is forced.
+ */
+__rte_experimental
+int rte_set_max_simd_bitwidth(uint16_t bitwidth);
+
/**
* Request iopl privilege for all RPL.
*
diff --git a/lib/librte_eal/ppc/include/rte_vect.h b/lib/librte_eal/ppc/include/rte_vect.h
index b0545c878c..a69aabc568 100644
--- a/lib/librte_eal/ppc/include/rte_vect.h
+++ b/lib/librte_eal/ppc/include/rte_vect.h
@@ -15,6 +15,8 @@
extern "C" {
#endif
+#define RTE_DEFAULT_SIMD_BITWIDTH RTE_SIMD_256
+
typedef vector signed int xmm_t;
#define XMM_SIZE (sizeof(xmm_t))
diff --git a/lib/librte_eal/rte_eal_exports.def b/lib/librte_eal/rte_eal_exports.def
index 16f8e33874..3516aacfe4 100644
--- a/lib/librte_eal/rte_eal_exports.def
+++ b/lib/librte_eal/rte_eal_exports.def
@@ -60,6 +60,7 @@ EXPORTS
rte_exit
rte_free
rte_get_master_lcore
+ rte_get_max_simd_bitwidth
rte_get_next_lcore
rte_get_tsc_hz
rte_hexdump
@@ -148,6 +149,7 @@ EXPORTS
rte_service_set_stats_enable
rte_service_start_with_defaults
rte_set_application_usage_hook
+ rte_set_max_simd_bitwidth
rte_socket_count
rte_socket_id
rte_socket_id_by_idx
diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
index a93dea9fe6..c1fc1b0783 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -399,7 +399,9 @@ EXPERIMENTAL {
# added in 20.11
__rte_eal_trace_generic_size_t;
+ rte_get_max_simd_bitwidth;
rte_service_lcore_may_be_active;
+ rte_set_max_simd_bitwidth;
};
INTERNAL {
diff --git a/lib/librte_eal/x86/include/rte_vect.h b/lib/librte_eal/x86/include/rte_vect.h
index 64383c3606..f0aad9615e 100644
--- a/lib/librte_eal/x86/include/rte_vect.h
+++ b/lib/librte_eal/x86/include/rte_vect.h
@@ -36,6 +36,8 @@
extern "C" {
#endif
+#define RTE_DEFAULT_SIMD_BITWIDTH RTE_SIMD_256
+
typedef __m128i xmm_t;
#define XMM_SIZE (sizeof(xmm_t))
--
2.22.0
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