[dpdk-dev] [PATCH] mem: fix cleanup on Windows

[Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>]

rte_mem_unmap() called from rte_eal_memory_detach() fails on Windows
with message "EAL: Could not unmap memory: No error". This is because
on Windows memory is not allocated using mapping. Confusing "No error"
is caused by using errno instead of rte_errno set by rte_mem_unmap().

Multi-process is not supported on Windows and --in-memory is forced,
so detaching memory is not needed on cleanup. Bypass the function
in this case. Fix error handling to produce proper log message.

Fixes: dfbc61a2f9a6 ("mem: detach memsegs on cleanup")
Cc: Anatoly Burakov <anatoly.burakov@intel.com>

Reported-by: Jie Zhou <jizh@microsoft.com>
Suggested-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
---
 lib/librte_eal/common/eal_common_memory.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
index 0e99986d3d..9ef9c65ac8 100644
--- a/lib/librte_eal/common/eal_common_memory.c
+++ b/lib/librte_eal/common/eal_common_memory.c
@@ -1010,6 +1010,13 @@ rte_eal_memory_detach(void)
 	size_t page_sz = rte_mem_page_size();
 	unsigned int i;
 
+#ifdef RTE_EXEC_ENV_WINDOWS
+	/* Multi-process is not supported, detaching is not needed.
+	 * mcfg->mp_status can't be used: it's always "unknown" on Windows.
+	 */
+	return 0;
+#endif
+
 	rte_rwlock_write_lock(&mcfg->memory_hotplug_lock);
 
 	/* detach internal memory subsystem data first */
@@ -1032,7 +1039,7 @@ rte_eal_memory_detach(void)
 		if (!msl->external)
 			if (rte_mem_unmap(msl->base_va, msl->len) != 0)
 				RTE_LOG(ERR, EAL, "Could not unmap memory: %s\n",
-						strerror(errno));
+						rte_strerror(rte_errno));
 
 		/*
 		 * we are detaching the fbarray rather than destroying because
-- 
2.29.3