[v2] mem: Fix anonymous mapping on Power9.

  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>
---
I updated the documentation and release notes as suggested by Thomas.
Thank you.

 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(-)
  

> -----ÓʼþÔ­¼þ-----
> ·¢¼þÈË: David Wilder <dwilder@us.ibm.com>
> ·¢ËÍʱ¼ä: 2018Äê11ÔÂ16ÈÕ 10:08
> ÊÕ¼þÈË: dev@dpdk.org
> ³­ËÍ: stable@dpdk.org; pradeep@us.ibm.com; chaozhu@linux.vnet.ibm.com;
> thomas@monjalon.net
> Ö÷Ìâ: [PATCH v2] mem: Fix anonymous mapping on Power9.
>
> 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>
> ---
> I updated the documentation and release notes as suggested by Thomas.
> Thank you.
>
>  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..87188a6be 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
> suported.
>
>  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
Thanks David!  Looking forward to the patch support for P8.

Acked-by: Chao Zhu <chaozhu@linux.vnet.ibm.com>