mem: fix cleanup when multi-process is disabled

rte_eal_memory_detach() did not account for cases where multi-process
mode is disabled: --in-memory and --no-shconf. This resulted
in unmapping memory that had not been mapped, which caused errors:

    EAL: Could not unmap memory: No error   (Windows)
    EAL: Cannot munmap(0x1d47f40, 0x7000): Invalid argument  (Linux)

Confusing "No error" was caused by using errno instead of rte_errno
set by rte_mem_unmap().

Skip detaching memory altogether when --in-memory is specified.
Skip unmapping configuration when it's not shared.
Fix and add error handling to produce proper log messages.

Fixes: dfbc61a2f9a6 ("mem: detach memsegs on cleanup")

Reported-by: Jie Zhou <jizh@microsoft.com>
Suggested-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Acked-by: Ranjit Menon <ranjit.menon@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
index 0e99986..2581dd5 100644 (file)
--- a/lib/librte_eal/common/eal_common_memory.c
+++ b/lib/librte_eal/common/eal_common_memory.c
@@ -1006,10 +1006,15 @@ rte_extmem_detach(void *va_addr, size_t len)
 int
 rte_eal_memory_detach(void)
 {
+       const struct internal_config *internal_conf =
+               eal_get_internal_configuration();
        struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
        size_t page_sz = rte_mem_page_size();
        unsigned int i;
 
+       if (internal_conf->in_memory == 1)
+               return 0;
+
        rte_rwlock_write_lock(&mcfg->memory_hotplug_lock);
 
        /* detach internal memory subsystem data first */
@@ -1032,7 +1037,7 @@ 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
@@ -1050,7 +1055,11 @@ rte_eal_memory_detach(void)
         * config - we can't zero it out because it might still be referenced
         * by other processes.
         */
-       rte_mem_unmap(mcfg, RTE_ALIGN(sizeof(*mcfg), page_sz));
+       if (internal_conf->no_shconf == 0) {
+               if (rte_mem_unmap(mcfg, RTE_ALIGN(sizeof(*mcfg), page_sz)) != 0)
+                       RTE_LOG(ERR, EAL, "Could not unmap shared memory config: %s\n",
+                                       rte_strerror(rte_errno));
+       }
        rte_eal_get_configuration()->mem_config = NULL;
 
        return 0;