patches for DPDK stable branches
 help / color / mirror / Atom feed
* [dpdk-stable] [PATCH 19.11 1/2] mem: exclude unused memory from core dump
@ 2021-02-22 11:58 luca.boccassi
  2021-02-22 11:58 ` [dpdk-stable] [PATCH 19.11 2/2] mem: fix build luca.boccassi
  0 siblings, 1 reply; 3+ messages in thread
From: luca.boccassi @ 2021-02-22 11:58 UTC (permalink / raw)
  To: stable; +Cc: stephen, Li Feng, Anatoly Burakov

From: Li Feng <fengli@smartx.com>

[ backported from upstream commit d72e4042c5ebda7af81448b387af8218136402d0 ]

Currently, even though memory is mapped with PROT_NONE, this does not
cause it to be excluded from core dumps. This is counter-productive,
because in a lot of cases, this memory will go unused (e.g. when the
memory subsystem preallocates VA space but hasn't yet mapped physical
pages into it).

Use `madvise()` call with MADV_DONTDUMP/MADV_NOCORE to exclude the
unused memory from being dumped.

Signed-off-by: Li Feng <fengli@smartx.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
As requested by Stephen. This stops coredumps from DPDK applications
from massively inflating in size with unused memory chunks.

 lib/librte_eal/common/eal_common_memory.c | 15 +++++++++++++++
 lib/librte_eal/linux/eal/eal_memalloc.c   |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
index cc7d54e0c7..9a797a4fa3 100644
--- a/lib/librte_eal/common/eal_common_memory.c
+++ b/lib/librte_eal/common/eal_common_memory.c
@@ -40,6 +40,14 @@
 static void *next_baseaddr;
 static uint64_t system_page_sz;
 
+#ifdef RTE_EXEC_ENV_LINUX
+#define RTE_DONTDUMP MADV_DONTDUMP
+#elif RTE_EXEC_ENV_FREEBSD
+#define RTE_DONTDUMP MADV_NOCORE
+#else
+#error "madvise doesn't support this OS"
+#endif
+
 #define MAX_MMAP_WITH_DEFINED_ADDR_TRIES 5
 void *
 eal_get_virtual_area(void *requested_addr, size_t *size,
@@ -179,6 +187,13 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
 			munmap(aligned_end, after_len);
 	}
 
+	if (!unmap) {
+		/* Exclude these pages from a core dump. */
+		if (madvise(aligned_addr, *size, RTE_DONTDUMP) != 0)
+			RTE_LOG(DEBUG, EAL, "madvise failed: %s\n",
+				strerror(errno));
+	}
+
 	return aligned_addr;
 }
 
diff --git a/lib/librte_eal/linux/eal/eal_memalloc.c b/lib/librte_eal/linux/eal/eal_memalloc.c
index 51d239de37..22f1ff68eb 100644
--- a/lib/librte_eal/linux/eal/eal_memalloc.c
+++ b/lib/librte_eal/linux/eal/eal_memalloc.c
@@ -710,6 +710,9 @@ free_seg(struct rte_memseg *ms, struct hugepage_info *hi,
 		return -1;
 	}
 
+	if (madvise(ms->addr, ms->len, MADV_DONTDUMP) != 0)
+		RTE_LOG(DEBUG, EAL, "madvise failed: %s\n", strerror(errno));
+
 	exit_early = false;
 
 	/* if we're using anonymous hugepages, nothing to be done */
-- 
2.29.2


^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-02-22 14:56 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-02-22 11:58 [dpdk-stable] [PATCH 19.11 1/2] mem: exclude unused memory from core dump luca.boccassi
2021-02-22 11:58 ` [dpdk-stable] [PATCH 19.11 2/2] mem: fix build luca.boccassi
2021-02-22 14:55   ` Christian Ehrhardt

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).