On 2015/06/04 22:02, Xishi Qiu wrote:
Add a new interface in path /proc/sys/vm/mirrorable. When set to 1, it means
we should allocate mirrored memory for both user and kernel processes.
Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx>
I can't see why do we need this switch. If this is set, all GFP_HIGHUSER will use
mirrored memory ?
Or will you add special MMAP/madvise flag to use mirrored memory ?
Thanks,
-Kame
---
include/linux/mmzone.h | 1 +
kernel/sysctl.c | 9 +++++++++
mm/page_alloc.c | 1 +
3 files changed, 11 insertions(+)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index f82e3ae..20888dd 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -85,6 +85,7 @@ struct mirror_info {
};
extern struct mirror_info mirror_info;
+extern int sysctl_mirrorable;
# define is_migrate_mirror(migratetype) unlikely((migratetype) == MIGRATE_MIRROR)
#else
# define is_migrate_mirror(migratetype) false
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 2082b1a..dc2625e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1514,6 +1514,15 @@ static struct ctl_table vm_table[] = {
.extra2 = &one,
},
#endif
+#ifdef CONFIG_MEMORY_MIRROR
+ {
+ .procname = "mirrorable",
+ .data = &sysctl_mirrorable,
+ .maxlen = sizeof(sysctl_mirrorable),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ },
+#endif
{
.procname = "user_reserve_kbytes",
.data = &sysctl_user_reserve_kbytes,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 249a8f6..63b90ca 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -212,6 +212,7 @@ int user_min_free_kbytes = -1;
#ifdef CONFIG_MEMORY_MIRROR
struct mirror_info mirror_info;
+int sysctl_mirrorable = 0;
#endif
static unsigned long __meminitdata nr_kernel_pages;
--
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