To simplify use on systems with large numbers of cores, where it becomes
more awkward to use CPU cores numbered above 128, we add to EAL the "-L"
or "--lcores-remapped" option, which simply takes a list of cores to run
on, and maps them to lcore ids starting at a defined base (0 by
default).
To enable secondary process use of this, we also add in an extra flag
--lcoreid-base, which changes the starting lcore id from 0. This flag is
mandatory in secondary processes, to ensure that we don't have lcore ids
that overlap between primary and secondary.
Signed-off-by: Bruce Richardson <bruce.richard...@intel.com>
---
doc/guides/linux_gsg/eal_args.include.rst | 46 ++++++++++++-
doc/guides/rel_notes/release_25_11.rst | 9 +++
lib/eal/common/eal_common_options.c | 79 +++++++++++++++++++++--
lib/eal/common/eal_option_list.h | 2 +
4 files changed, 130 insertions(+), 6 deletions(-)
diff --git a/doc/guides/linux_gsg/eal_args.include.rst
b/doc/guides/linux_gsg/eal_args.include.rst
index 0b17879d42..d45d79b827 100644
--- a/doc/guides/linux_gsg/eal_args.include.rst
+++ b/doc/guides/linux_gsg/eal_args.include.rst
@@ -4,6 +4,28 @@
Lcore-related options
~~~~~~~~~~~~~~~~~~~~~
+* ``-L, --lcores-remapped <core list>``
+
+ List of physical CPU cores to use,
+ with each core assigned a sequential logical core (lcore) ID starting from
0.
+ This is a simplified alternative to ``--lcores``, described below,
+ for cases where you want to use specific physical cores,
+ (some or all of which have physical ids greater than RTE_MAX_LCORE)
+ but don't need complex logical-to-physical core mappings.
+
+ The argument format is a standard core list: ``<c1>[-c2][,c3[-c4],...]``
+ where ``c1``, ``c2``, etc are physical core indexes.
+
+ Examples:
+
+ ``--lcores-remapped=3-5``
+ Use physical cores 3, 4, and 5 as logical cores 0, 1, and 2 respectively.
+ This is equivalent to ``--lcores=0@3,1@4,2@5``.
+
+ ``--lcores-remapped=150,152,154``
+ Use physical cores 150, 152, and 154 as logical cores 0, 1, and 2
respectively.
+ This is equivalent to ``--lcores=0@150,1@152,2@154``.
+
* ``-l, --lcores <core list>``
List of cores to run on
@@ -64,9 +86,31 @@ Lcore-related options
.. note::
- At a given instance only one core option ``--lcores``, ``-l`` or ``-c`` can
+ At a given instance only one core option ``--lcores`` / ``-l``, or
``--lcores-remapped`` / ``-L`` can
be used.
+* ``--lcoreid-base <base ID>``
+
+ Adjust the base logical core ID for ``--lcores-remapped`` (default: 0).
+ When used with ``--lcores-remapped``,
+ logical core numbering starts from this value instead of 0.
+ This is particularly useful for secondary processes in a multi-process
setup,
+ as lcore_ids must all be unique across all processes.
+
+ Example:
+
+ ``--lcores-remapped=3-5 --lcoreid-base=10``
+ Use physical cores 3, 4, and 5 as logical cores 10, 11, and 12
respectively.
+ This is equivalent to ``--lcores=10@3,11@4,12@5``.
+
+.. note::
+
+ The ``--lcores-remapped`` option is ignored if used with ``--lcores``,
``-l`` option.
+
+.. note::
+
+ For secondary processes, ``--lcoreid-base`` *must* be specified when using
``--lcores-remapped``.
+
* ``--main-lcore <core ID>``
Core ID that is used as main.
diff --git a/doc/guides/rel_notes/release_25_11.rst
b/doc/guides/rel_notes/release_25_11.rst
index 75bbd0e821..39fc800f6e 100644
--- a/doc/guides/rel_notes/release_25_11.rst
+++ b/doc/guides/rel_notes/release_25_11.rst
@@ -55,6 +55,15 @@ New Features
Also, make sure to start the actual text at the margin.
=======================================================
+* **Added EAL lcores-remapped(-L) argument to simplify running on
higher-numbered cores.**
+
+ Added new EAL command line arguments ``-L, --lcores-remapped`` and
``--lcoreid-base``
+ that provide a simplified way to specify which physical CPU cores to use.
+ The ``--lcores-remapped`` argument allows specifying a list of physical
cores on which the EAL threads are to be spawned,
+ with each thread being assigned an lcore id in sequence.
+ The lcore numbering starts at 0 by default, though this can be overridden
using ``--lcoreid-base``.
+ See :doc:`../linux_gsg/eal_args.include` for more details.
+
* **Allow overriding the automatic usage/help generation in argparse library.**
The argparse library now supports overriding the automatic help text
generation,
diff --git a/lib/eal/common/eal_common_options.c
b/lib/eal/common/eal_common_options.c
index c568e59ef3..af2bd33fd4 100644
--- a/lib/eal/common/eal_common_options.c
+++ b/lib/eal/common/eal_common_options.c
@@ -232,6 +232,8 @@ eal_collate_args(int argc, char **argv)
/* for non-list args, we can just check for zero/null values using
macro */
if (CONFLICTING_OPTIONS(args, coremask, lcores) ||
+ CONFLICTING_OPTIONS(args, coremask, lcores_remapped) ||
+ CONFLICTING_OPTIONS(args, lcores, lcores_remapped) ||
CONFLICTING_OPTIONS(args, service_coremask,
service_corelist) ||
CONFLICTING_OPTIONS(args, no_telemetry, telemetry) ||
CONFLICTING_OPTIONS(args, memory_size, numa_mem) ||
@@ -1351,6 +1353,67 @@ eal_parse_lcores(const char *lcores)
return ret;
}
+static int
+eal_parse_lcores_remapped(const char *corelist, const char *base_str)
+{
+ struct rte_config *cfg = rte_eal_get_configuration();
+ rte_cpuset_t phys_cores;
+
+ /* Reset lcore config */
+ for (int i = 0; i < RTE_MAX_LCORE; i++) {
+ cfg->lcore_role[i] = ROLE_OFF;
+ lcore_config[i].core_index = -1;
+ CPU_ZERO(&lcore_config[i].cpuset);
+ }
+
+ /* Parse the physical core list using rte_argparse_parse_type */
+ if (rte_argparse_parse_type(corelist, RTE_ARGPARSE_VALUE_TYPE_CORELIST,
&phys_cores) < 0) {
+ EAL_LOG(ERR, "Invalid lcores-remapped format: '%s'", corelist);
+ return -1;
+ }
+ if (CPU_COUNT(&phys_cores) == 0) {
+ EAL_LOG(ERR, "No valid cores specified in lcores-remapped:
'%s'", corelist);
+ return -1;
+ }
+
+ if (check_cpuset(&phys_cores) < 0)
+ return -1;
+
+ /* Parse base lcore ID if provided */
+ unsigned int base_lcore = 0;
+ if (base_str != NULL) {
+ char *end;
+ errno = 0;
+ base_lcore = strtoul(base_str, &end, 10);
+ if (errno || end == NULL || *end != '\0' || base_lcore >=
RTE_MAX_LCORE) {
+ EAL_LOG(ERR, "Invalid lcoreid-base: '%s'", base_str);
+ return -1;
+ }
+ }
+
+ /* Map logical cores starting from base_lcore to physical cores */
+ unsigned int count = 0;
+ for (int i = 0; i < CPU_SETSIZE && count < RTE_MAX_LCORE; i++) {
+ if (CPU_ISSET(i, &phys_cores)) {
+ const unsigned int lcore_id = base_lcore + count;
+ if (lcore_id >= RTE_MAX_LCORE) {
+ EAL_LOG(ERR, "Logical lcore %u exceeds
RTE_MAX_LCORE (%d)",
+ lcore_id, RTE_MAX_LCORE);
+ return -1;
+ }
+
+ /* Set up the lcore configuration */
+ cfg->lcore_role[lcore_id] = ROLE_RTE;
+ lcore_config[lcore_id].core_index = count;
+ CPU_SET(i, &lcore_config[lcore_id].cpuset);
+ count++;
+ }
+ }
+
+ cfg->lcore_count = count;
+ return 0;
+}
+
static void
eal_log_usage(void)
{
@@ -1842,6 +1905,8 @@ eal_parse_args(void)
EAL_LOG(ERR, "invalid process type: %s",
args.proc_type);
return -1;
}
+ if (int_cfg->process_type == RTE_PROC_AUTO)
+ int_cfg->process_type = eal_proc_type_detect();
}
/* device -a/-b/-vdev options*/
@@ -1882,6 +1947,15 @@ eal_parse_args(void)
return -1;
}
core_parsed = 1;
+ } else if (args.lcores_remapped != NULL) {
+ if (int_cfg->process_type == RTE_PROC_SECONDARY &&
args.lcoreid_base == NULL) {
+ EAL_LOG(ERR, "Must use --lcoreid-base with
--lcores-remapped when running secondary processes");
+ return -1;
+ }
+ /* Parse the remapped cores list */
+ if (eal_parse_lcores_remapped(args.lcores_remapped,
args.lcoreid_base) < 0)
+ return -1;
+ core_parsed = 1;
}
/* service core options */
if (args.service_coremask != NULL) {
@@ -2187,8 +2261,6 @@ eal_adjust_config(struct internal_config *internal_cfg)
{
int i;
struct rte_config *cfg = rte_eal_get_configuration();
- struct internal_config *internal_conf =
- eal_get_internal_configuration();
if (!core_parsed)
eal_auto_detect_cores(cfg);
@@ -2198,9 +2270,6 @@ eal_adjust_config(struct internal_config *internal_cfg)
return -1;
}
- if (internal_conf->process_type == RTE_PROC_AUTO)
- internal_conf->process_type = eal_proc_type_detect();
-
compute_ctrl_threads_cpuset(internal_cfg);
/* if no memory amounts were requested, this will result in 0 and
diff --git a/lib/eal/common/eal_option_list.h b/lib/eal/common/eal_option_list.h
index dd148b7fed..976df16347 100644
--- a/lib/eal/common/eal_option_list.h
+++ b/lib/eal/common/eal_option_list.h
@@ -42,6 +42,8 @@ OPT_STR_ARG("--huge-unlink", NULL, "Unlink hugetlbfs files on
exit (existing|alw
BOOL_ARG("--in-memory", NULL, "DPDK should not create shared mmap files in
filesystem (disables secondary process support)", in_memory)
STR_ARG("--iova-mode", NULL, "IOVA mapping mode, physical (pa)/virtual (va)",
iova_mode)
STR_ARG("--lcores", "-l", "List of CPU cores to use", lcores)
+STR_ARG("--lcores-remapped", "-L", "List of cores to use, assigning each a
sequential lcore ID (start 0 by default)", lcores_remapped)
+STR_ARG("--lcoreid-base", NULL, "Number remapped lcores from <N>, rather than
0 (e.g. for secondary processes)", lcoreid_base)
BOOL_ARG("--legacy-mem", NULL, "Enable legacy memory behavior", legacy_mem)
OPT_STR_ARG("--log-color", NULL, "Enable/disable color in log output",
log_color)
STR_ARG("--log-level", NULL, "Log level for loggers; use log-level=help for
list of log types and levels", log_level)
--
2.48.1
