patch 'eal: warn if no lcore is available' has been queued to stable release 23.11.5

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 23.11.5

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 06/28/25. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://git.dpdk.org/dpdk-stable/log/?h=23.11-staging

This queued commit can be viewed at:
https://git.dpdk.org/dpdk-stable/commit/?h=23.11-staging&id=78136965e47224fb44e6e26699aac1f03cc68e05

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From 78136965e47224fb44e6e26699aac1f03cc68e05 Mon Sep 17 00:00:00 2001
From: David Marchand <david.marchand at redhat.com>
Date: Thu, 8 May 2025 07:19:15 +0200
Subject: [PATCH] eal: warn if no lcore is available
Cc: Xueming Li <xuemingl at nvidia.com>

[ upstream commit 2ea1d30dc938866a983156473579d10bddb4951e ]

On systems with more cpu than RTE_MAX_LCORE, starting DPDK with
cores >= RTE_MAX_LCORE ends up with an ambiguous error log.

Example with RTE_MAX_LCORE=8:
$ taskset -c 8 ./build/app/dpdk-testpmd
EAL: Detected CPU lcores: 8
EAL: Detected NUMA nodes: 1
EAL: Invalid 'command line' arguments.
EAL: Error - exiting with code: 1
Cannot init EAL: Invalid argument

Add a better hint to help the user.

Fixes: 2eba8d21f3c9 ("eal: restrict cores auto detection")

Signed-off-by: David Marchand <david.marchand at redhat.com>
Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 lib/eal/common/eal_common_options.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/eal/common/eal_common_options.c b/lib/eal/common/eal_common_options.c
index aec51736f2..110d95940d 100644
--- a/lib/eal/common/eal_common_options.c
+++ b/lib/eal/common/eal_common_options.c
@@ -2025,6 +2025,11 @@ eal_adjust_config(struct internal_config *internal_cfg)
 	if (!core_parsed)
 		eal_auto_detect_cores(cfg);
 
+	if (cfg->lcore_count == 0) {
+		RTE_LOG(ERR, EAL, "No detected lcore is enabled, please check the core list\n");
+		return -1;
+	}
+
 	if (internal_conf->process_type == RTE_PROC_AUTO)
 		internal_conf->process_type = eal_proc_type_detect();
 
-- 
2.34.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2025-06-26 19:59:20.467822615 +0800
+++ 0072-eal-warn-if-no-lcore-is-available.patch	2025-06-26 19:59:17.482418040 +0800
@@ -1 +1 @@
-From 2ea1d30dc938866a983156473579d10bddb4951e Mon Sep 17 00:00:00 2001
+From 78136965e47224fb44e6e26699aac1f03cc68e05 Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Xueming Li <xuemingl at nvidia.com>
+
+[ upstream commit 2ea1d30dc938866a983156473579d10bddb4951e ]
@@ -20 +22,0 @@
-Cc: stable at dpdk.org
@@ -29 +31 @@
-index b6fff7ec05..b194d0ee06 100644
+index aec51736f2..110d95940d 100644
@@ -32 +34 @@
-@@ -2052,6 +2052,11 @@ eal_adjust_config(struct internal_config *internal_cfg)
+@@ -2025,6 +2025,11 @@ eal_adjust_config(struct internal_config *internal_cfg)
@@ -37 +39 @@
-+		EAL_LOG(ERR, "No detected lcore is enabled, please check the core list");
++		RTE_LOG(ERR, EAL, "No detected lcore is enabled, please check the core list\n");