[merged mm-stable] mm-secretmem-make-it-on-by-default.patch removed from -mm tree

[merged mm-stable] mm-secretmem-make-it-on-by-default.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/secretmem: make it on by default
has been removed from the -mm tree.  Its filename was
     mm-secretmem-make-it-on-by-default.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: "Mike Rapoport (IBM)" <rppt@kernel.org>
Subject: mm/secretmem: make it on by default
Date: Mon, 15 May 2023 11:34:00 +0300

Following the discussion about direct map fragmentaion at LSF/MM [1], it
appears that direct map fragmentation has a negligible effect on kernel
data accesses.  Since the only reason that warranted secretmem to be
disabled by default was concern about performance regression caused by the
direct map fragmentation, it makes perfect sense to lift this restriction
and make secretmem enabled.

secretmem obeys RLIMIT_MEMBLOCK and as such it is not expected to cause
large fragmentation of the direct map or meaningfull increase in page
tables allocated during split of the large mappings in the direct map.

The secretmem.enable parameter is retained to allow system administrators
to disable secretmem at boot.

Switch the default setting of secretmem.enable parameter to 1.

Link: https://lwn.net/Articles/931406/ [1]
Link: https://lkml.kernel.org/r/20230515083400.3563974-1-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/secretmem.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/secretmem.c~mm-secretmem-make-it-on-by-default
+++ a/mm/secretmem.c
@@ -35,7 +35,7 @@
 #define SECRETMEM_MODE_MASK	(0x0)
 #define SECRETMEM_FLAGS_MASK	SECRETMEM_MODE_MASK
 
-static bool secretmem_enable __ro_after_init;
+static bool secretmem_enable __ro_after_init = 1;
 module_param_named(enable, secretmem_enable, bool, 0400);
 MODULE_PARM_DESC(secretmem_enable,
 		 "Enable secretmem and memfd_secret(2) system call");
_

Patches currently in -mm which might be from rppt@kernel.org are