[dpdk-dev] [PATCH v3] mem: Fix anonymous mapping on Power9.

[David Wilder <dwilder@us.ibm.com>]

Removed the use of MAP_HUGETLB for anonymous mapping on ppc64.  The
MAP_HUGETLB had previously been added to workaround issues on IBM Power8
systems when mapping /dev/zero (see: commit
284ae3e9ff9a92575c28c858efd2c85c8de6d440).  In the current code the
MAP_HUGETLB flag will cause the anonymous mapping to fail on Power9.
Note, Power8 is currently failing to correctly mmap Hugepages, with and
without this change.

Signed-off-by: David Wilder <dwilder@us.ibm.com>
Reviewed-by: Pradeep Satyanarayana <pradeep@us.ibm.com>
---
V2- Updated release notes.
V3- fixed spelling.

 MAINTAINERS                                | 2 +-
 doc/guides/linux_gsg/sys_reqs.rst          | 6 ------
 doc/guides/rel_notes/release_18_11.rst     | 1 +
 lib/librte_eal/linuxapp/eal/eal_memalloc.c | 3 ---
 lib/librte_eal/linuxapp/eal/eal_memory.c   | 4 ----
 5 files changed, 2 insertions(+), 14 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 19353ac89..c4d2fd086 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -233,7 +233,7 @@ F: drivers/net/ixgbe/ixgbe_rxtx_vec_neon.c
 F: drivers/net/i40e/i40e_rxtx_vec_neon.c
 F: drivers/net/virtio/virtio_rxtx_simple_neon.c
 
-IBM POWER
+IBM POWER (alpha)
 M: Chao Zhu <chaozhu@linux.vnet.ibm.com>
 F: lib/librte_eal/common/arch/ppc_64/
 F: lib/librte_eal/common/include/arch/ppc_64/
diff --git a/doc/guides/linux_gsg/sys_reqs.rst b/doc/guides/linux_gsg/sys_reqs.rst
index e2230f37b..c02ec28c1 100644
--- a/doc/guides/linux_gsg/sys_reqs.rst
+++ b/doc/guides/linux_gsg/sys_reqs.rst
@@ -183,12 +183,6 @@ On a NUMA machine, pages should be allocated explicitly on separate nodes::
 
     For 1G pages, it is not possible to reserve the hugepage memory after the system has booted.
 
-    On IBM POWER system, the nr_overcommit_hugepages should be set to the same value as nr_hugepages.
-    For example, if the required page number is 128, the following commands are used::
-
-        echo 128 > /sys/kernel/mm/hugepages/hugepages-16384kB/nr_hugepages
-        echo 128 > /sys/kernel/mm/hugepages/hugepages-16384kB/nr_overcommit_hugepages
-
 Using Hugepages with the DPDK
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/doc/guides/rel_notes/release_18_11.rst b/doc/guides/rel_notes/release_18_11.rst
index 51d007582..a271badbe 100644
--- a/doc/guides/rel_notes/release_18_11.rst
+++ b/doc/guides/rel_notes/release_18_11.rst
@@ -532,6 +532,7 @@ Known Issues
   driver; the Linux netvsc device must be brought up before the netvsc device is
   unbound and passed to the DPDK.
 
+* IBM Power8 is not supported by this release of DPDK. IBM Power9 is supported.
 
 Tested Platforms
 ----------------
diff --git a/lib/librte_eal/linuxapp/eal/eal_memalloc.c b/lib/librte_eal/linuxapp/eal/eal_memalloc.c
index 48b9c7360..784939566 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memalloc.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memalloc.c
@@ -753,9 +753,6 @@ alloc_seg(struct rte_memseg *ms, void *addr, int socket_id,
 	munmap(addr, alloc_sz);
 unmapped:
 	flags = MAP_FIXED;
-#ifdef RTE_ARCH_PPC_64
-	flags |= MAP_HUGETLB;
-#endif
 	new_addr = eal_get_virtual_area(addr, &alloc_sz, alloc_sz, 0, flags);
 	if (new_addr != addr) {
 		if (new_addr != NULL)
diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index 48b23ce19..6f94621d4 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -847,10 +847,6 @@ alloc_va_space(struct rte_memseg_list *msl)
 	void *addr;
 	int flags = 0;
 
-#ifdef RTE_ARCH_PPC_64
-	flags |= MAP_HUGETLB;
-#endif
-
 	page_sz = msl->page_sz;
 	mem_sz = page_sz * msl->memseg_arr.len;
 
-- 
2.19.1