[dpdk-stable] patch 'mem: mark pages as not accessed when reserving VA' has been queued to stable release 19.11.3

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/21/20. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Thanks.

Luca Boccassi

---
>From d0e456e9b1af8594ed22382e33bc6e1d5acec994 Mon Sep 17 00:00:00 2001
From: David Marchand <david.marchand at redhat.com>
Date: Mon, 9 Mar 2020 15:54:42 +0100
Subject: [PATCH] mem: mark pages as not accessed when reserving VA

[ upstream commit 8a4baf06c17a806696fb10aba36fce7471983028 ]

When the memory allocator reserves virtual addresses, it still does not
know what they will be used for.
Besides, huge areas are reserved for memory hotplug in multiprocess
setups. But most of the pages are unused in the whole life of the
processes.

Change protection mode to PROT_NONE when only reserving VA.
The memory allocator already switches to the right mode when making use
of it.

It also has the nice effect of getting those pages skipped by the kernel
when calling mlockall() or when a coredump gets generated.

Suggested-by: Andrea Arcangeli <aarcange at redhat.com>
Signed-off-by: David Marchand <david.marchand at redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
Acked-by: Aaron Conole <aconole at redhat.com>
Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 lib/librte_eal/common/eal_common_memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c
index 4a9cc1f19a..cc7d54e0c7 100644
--- a/lib/librte_eal/common/eal_common_memory.c
+++ b/lib/librte_eal/common/eal_common_memory.c
@@ -97,7 +97,7 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
 			return NULL;
 		}
 
-		mapped_addr = mmap(requested_addr, (size_t)map_sz, PROT_READ,
+		mapped_addr = mmap(requested_addr, (size_t)map_sz, PROT_NONE,
 				mmap_flags, -1, 0);
 		if (mapped_addr == MAP_FAILED && allow_shrink)
 			*size -= page_sz;
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-05-19 13:56:19.274078176 +0100
+++ 0011-mem-mark-pages-as-not-accessed-when-reserving-VA.patch	2020-05-19 13:56:18.175501026 +0100
@@ -1,8 +1,10 @@
-From 8a4baf06c17a806696fb10aba36fce7471983028 Mon Sep 17 00:00:00 2001
+From d0e456e9b1af8594ed22382e33bc6e1d5acec994 Mon Sep 17 00:00:00 2001
 From: David Marchand <david.marchand at redhat.com>
 Date: Mon, 9 Mar 2020 15:54:42 +0100
 Subject: [PATCH] mem: mark pages as not accessed when reserving VA
 
+[ upstream commit 8a4baf06c17a806696fb10aba36fce7471983028 ]
+
 When the memory allocator reserves virtual addresses, it still does not
 know what they will be used for.
 Besides, huge areas are reserved for memory hotplug in multiprocess
@@ -16,8 +18,6 @@
 It also has the nice effect of getting those pages skipped by the kernel
 when calling mlockall() or when a coredump gets generated.
 
-Cc: stable at dpdk.org
-
 Suggested-by: Andrea Arcangeli <aarcange at redhat.com>
 Signed-off-by: David Marchand <david.marchand at redhat.com>
 Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>