[dpdk-dev] [PATCH v3] mem: warn user when running without NUMA support

[Anatoly Burakov <anatoly.burakov@intel.com>]

Running in non-legacy mode on a NUMA-enabled system without libnuma
is unsupported, so explicitly print out a warning when trying to
do so.

Running in legacy mode without libnuma is still supported whether or
not we are running with libnuma support enabled, so also fix init to
allow that scenario.

Cc: stable@dpdk.org

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---

Notes:
    v3:
    - Fix ill-conceived v2 "fix" by adding getopt header
      to eal_options.h instead of removing the include

 lib/librte_eal/common/eal_options.h     |  2 ++
 lib/librte_eal/linux/eal/eal_memalloc.c |  3 +++
 lib/librte_eal/linux/eal/eal_memory.c   | 14 ++++++++++++--
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/common/eal_options.h b/lib/librte_eal/common/eal_options.h
index 58ee9ae33..9855429e5 100644
--- a/lib/librte_eal/common/eal_options.h
+++ b/lib/librte_eal/common/eal_options.h
@@ -5,6 +5,8 @@
 #ifndef EAL_OPTIONS_H
 #define EAL_OPTIONS_H
 
+#include "getopt.h"
+
 enum {
 	/* long options mapped to a short option */
 #define OPT_HELP              "help"
diff --git a/lib/librte_eal/linux/eal/eal_memalloc.c b/lib/librte_eal/linux/eal/eal_memalloc.c
index b6fb183db..4e83a1a19 100644
--- a/lib/librte_eal/linux/eal/eal_memalloc.c
+++ b/lib/librte_eal/linux/eal/eal_memalloc.c
@@ -725,6 +725,9 @@ alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
 			__func__, socket_id, cur_socket_id);
 		goto mapped;
 	}
+#else
+	if (rte_socket_count() > 1)
+		RTE_LOG(DEBUG, EAL, "%s(): not checking hugepage NUMA node.\n");
 #endif
 
 	ms->addr = addr;
diff --git a/lib/librte_eal/linux/eal/eal_memory.c b/lib/librte_eal/linux/eal/eal_memory.c
index 1b96b576e..e5a0e57ff 100644
--- a/lib/librte_eal/linux/eal/eal_memory.c
+++ b/lib/librte_eal/linux/eal/eal_memory.c
@@ -50,6 +50,7 @@
 #include "eal_internal_cfg.h"
 #include "eal_filesystem.h"
 #include "eal_hugepages.h"
+#include "eal_options.h"
 
 #define PFN_MASK_SIZE	8
 
@@ -2088,7 +2089,8 @@ memseg_primary_init_32(void)
 		socket_id = rte_socket_id_by_idx(i);
 
 #ifndef RTE_EAL_NUMA_AWARE_HUGEPAGES
-		if (socket_id > 0)
+		/* we can still sort pages by socket in legacy mode */
+		if (!internal_config.legacy_mem && socket_id > 0)
 			break;
 #endif
 
@@ -2269,7 +2271,8 @@ memseg_primary_init(void)
 			int socket_id = rte_socket_id_by_idx(i);
 
 #ifndef RTE_EAL_NUMA_AWARE_HUGEPAGES
-			if (socket_id > 0)
+			/* we can still sort pages by socket in legacy mode */
+			if (!internal_config.legacy_mem && socket_id > 0)
 				break;
 #endif
 			memtypes[cur_type].page_sz = hugepage_sz;
@@ -2428,6 +2431,13 @@ rte_eal_memseg_init(void)
 	} else {
 		RTE_LOG(ERR, EAL, "Cannot get current resource limits\n");
 	}
+#ifndef RTE_EAL_NUMA_AWARE_HUGEPAGES
+	if (!internal_config.legacy_mem && rte_socket_count() > 1) {
+		RTE_LOG(WARNING, EAL, "DPDK is running on a NUMA system, but is compiled without NUMA support.\n");
+		RTE_LOG(WARNING, EAL, "This will have adverse consequences for performance and usability.\n");
+		RTE_LOG(WARNING, EAL, "Please use --"OPT_LEGACY_MEM" option, or recompile with NUMA support.\n");
+	}
+#endif
 
 	return rte_eal_process_type() == RTE_PROC_PRIMARY ?
 #ifndef RTE_ARCH_64
-- 
2.17.1