Hi Chao,
You mentioned that 'mmap will not respect the requested address hint',
how does the proposed change solves that?
Is it that hugepages map to a specific VA region, and without
MAP_HUGETLB you may get address from wrong region?
If mmap were to respect the hinted address, we could do this change
multi-arch without having to set overcommit hugepages?
fd = -1
addr = mmap(addr, (*size) + hugepage_sz, PROT_READ, MAP_PRIVATE |
MAP_ANONYMOUS | MAP_HUGETLB, fd, 0)
# Free hugepages mapping
addr = mmap(addr, (*size) + hugepage_sz, PROT_READ, MAP_PRIVATE |
MAP_ANONYMOUS, fd, 0)
What do you think?
Regards,
Sergio
On 06/04/2017 11:06, Chao Zhu wrote:
On IBM POWER platform, when mapping /dev/zero file to hugepage memory
space, mmap will not respect the requested address hint. This will cause
the memory initilization for the second process fails. This patch adds
the required mmap flags to make it work. Beside this, users need to set
the nr_overcommit_hugepages to expand the VA range. When
doing the initilization, users need to set both nr_hugepages and
nr_overcommit_hugepages to the same value, like 64, 128, etc.
Signed-off-by: Chao Zhu <chao...@linux.vnet.ibm.com>
---
lib/librte_eal/linuxapp/eal/eal_memory.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c
b/lib/librte_eal/linuxapp/eal/eal_memory.c
index a956bb2..e06186b 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -313,7 +313,11 @@ int rte_xen_dom0_supported(void)
}
do {
addr = mmap(addr,
+#ifndef RTE_ARCH_PPC_64
(*size) + hugepage_sz, PROT_READ, MAP_PRIVATE,
fd, 0);
+#else
+ (*size) + hugepage_sz, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS
| MAP_HUGETLB, fd, 0);
+#endif
if (addr == MAP_FAILED)
*size -= hugepage_sz;
} while (addr == MAP_FAILED && *size > 0);
@@ -1330,7 +1334,11 @@ static int huge_wrap_sigsetjmp(void)
* use mmap to get identical addresses as the primary process.
*/
base_addr = mmap(mcfg->memseg[s].addr, mcfg->memseg[s].len,
+#ifndef RTE_ARCH_PPC_64
PROT_READ, MAP_PRIVATE, fd_zero, 0);
+#else
+ PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
fd_zero, 0);
+#endif
if (base_addr == MAP_FAILED ||
base_addr != mcfg->memseg[s].addr) {
max_seg = s;
