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* [dpdk-dev] [PATCH] eal/mem: preallocate VA space in no-huge mode
@ 2020-01-24 17:01 Anatoly Burakov
  2020-01-24 17:05 ` [dpdk-dev] [PATCH v2] " Anatoly Burakov
  0 siblings, 1 reply; 10+ messages in thread
From: Anatoly Burakov @ 2020-01-24 17:01 UTC (permalink / raw)
  To: dev; +Cc: stable

When --no-huge mode is used, the memory is currently allocated with
mmap(NULL, ...). This is fine in most cases, but can fail in cases
where DPDK is run on a machine with an IOMMU that is of more limited
address width than that of a VA, because we're not specifying the
address hint for mmap() call.

Fix it by preallocating VA space before mapping it.

Cc: stable@dpdk.org

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---

Notes:
    I couldn't figure out which specific commit has introduced
    the issue, so there's no fix tag. The most likely candidate
    is one that introduced the DMA mask thing in the first place
    but i'm not sure.

 lib/librte_eal/linux/eal/eal_memory.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/linux/eal/eal_memory.c b/lib/librte_eal/linux/eal/eal_memory.c
index 43e4ffc757..672f8806dd 100644
--- a/lib/librte_eal/linux/eal/eal_memory.c
+++ b/lib/librte_eal/linux/eal/eal_memory.c
@@ -1340,6 +1340,8 @@ eal_legacy_hugepage_init(void)
 
 	/* hugetlbfs can be disabled */
 	if (internal_config.no_hugetlbfs) {
+		void *prealloc_addr;
+		size_t mem_sz;
 		struct rte_memseg_list *msl;
 		int n_segs, cur_seg, fd, flags;
 #ifdef MEMFD_SUPPORTED
@@ -1395,8 +1397,21 @@ eal_legacy_hugepage_init(void)
 			}
 		}
 #endif
-		addr = mmap(NULL, internal_config.memory, PROT_READ | PROT_WRITE,
-				flags, fd, 0);
+		/* preallocate address space for the memory, so that it can be
+		 * fit into the DMA mask.
+		 */
+		mem_sz = internal_config.memory;
+		prealloc_addr = eal_get_virtual_area(
+				NULL, &mem_sz, page_sz, 0, 0);
+		if (prealloc_addr == NULL) {
+			RTE_LOG(ERR, EAL,
+					"%s: reserving memory area failed: "
+					"%s\n",
+					__func__, strerror(errno));
+			return -1;
+		}
+		addr = mmap(prealloc_addr, internal_config.memory,
+				PROT_READ | PROT_WRITE, flags, fd, MAP_FIXED);
 		if (addr == MAP_FAILED) {
 			RTE_LOG(ERR, EAL, "%s: mmap() failed: %s\n", __func__,
 					strerror(errno));
-- 
2.17.1

^ permalink raw reply	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2020-03-27 10:16 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-24 17:01 [dpdk-dev] [PATCH] eal/mem: preallocate VA space in no-huge mode Anatoly Burakov
2020-01-24 17:05 ` [dpdk-dev] [PATCH v2] " Anatoly Burakov
2020-02-06 15:39   ` Thomas Monjalon
2020-02-06 21:07     ` Thomas Monjalon
2020-02-07 11:11   ` [dpdk-dev] [PATCH v3] " Anatoly Burakov
2020-03-25 14:39     ` [dpdk-dev] [dpdk-stable] " David Marchand
2020-03-26 17:06       ` Burakov, Anatoly
2020-03-27  6:33         ` David Marchand
     [not found]       ` <6473a4fe45d8437285fd8a1e931a1cb8@intel.com>
2020-03-27  2:23         ` Zhou, JunX W
2020-03-27 10:16       ` David Marchand

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