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-rw-r--r--init/Kconfig45
-rw-r--r--init/do_mounts.c45
-rw-r--r--init/main.c2
3 files changed, 72 insertions, 20 deletions
diff --git a/init/Kconfig b/init/Kconfig
index fed81b576f29..3ecd8a1178f1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -470,6 +470,7 @@ config TREE_RCU
config TREE_PREEMPT_RCU
bool "Preemptible tree-based hierarchical RCU"
depends on PREEMPT
+ select IRQ_WORK
help
This option selects the RCU implementation that is
designed for very large SMP systems with hundreds or
@@ -527,13 +528,29 @@ config RCU_USER_QS
config CONTEXT_TRACKING_FORCE
bool "Force context tracking"
depends on CONTEXT_TRACKING
- default CONTEXT_TRACKING
+ default y if !NO_HZ_FULL
help
- Probe on user/kernel boundaries by default in order to
- test the features that rely on it such as userspace RCU extended
- quiescent states.
- This test is there for debugging until we have a real user like the
- full dynticks mode.
+ The major pre-requirement for full dynticks to work is to
+ support the context tracking subsystem. But there are also
+ other dependencies to provide in order to make the full
+ dynticks working.
+
+ This option stands for testing when an arch implements the
+ context tracking backend but doesn't yet fullfill all the
+ requirements to make the full dynticks feature working.
+ Without the full dynticks, there is no way to test the support
+ for context tracking and the subsystems that rely on it: RCU
+ userspace extended quiescent state and tickless cputime
+ accounting. This option copes with the absence of the full
+ dynticks subsystem by forcing the context tracking on all
+ CPUs in the system.
+
+ Say Y only if you're working on the developpement of an
+ architecture backend for the context tracking.
+
+ Say N otherwise, this option brings an overhead that you
+ don't want in production.
+
config RCU_FANOUT
int "Tree-based hierarchical RCU fanout value"
@@ -1106,7 +1123,6 @@ config IPC_NS
config USER_NS
bool "User namespace"
- depends on UIDGID_CONVERTED
select UIDGID_STRICT_TYPE_CHECKS
default n
@@ -1140,20 +1156,8 @@ config NET_NS
endif # NAMESPACES
-config UIDGID_CONVERTED
- # True if all of the selected software conmponents are known
- # to have uid_t and gid_t converted to kuid_t and kgid_t
- # where appropriate and are otherwise safe to use with
- # the user namespace.
- bool
- default y
-
- # Filesystems
- depends on XFS_FS = n
-
config UIDGID_STRICT_TYPE_CHECKS
bool "Require conversions between uid/gids and their internal representation"
- depends on UIDGID_CONVERTED
default n
help
While the nececessary conversions are being added to all subsystems this option allows
@@ -1598,7 +1602,7 @@ endchoice
config SLUB_CPU_PARTIAL
default y
- depends on SLUB
+ depends on SLUB && SMP
bool "SLUB per cpu partial cache"
help
Per cpu partial caches accellerate objects allocation and freeing
@@ -1666,6 +1670,7 @@ config BASE_SMALL
menuconfig MODULES
bool "Enable loadable module support"
+ option modules
help
Kernel modules are small pieces of compiled code which can
be inserted in the running kernel, rather than being
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 816014c4627e..a51cddc2ff8c 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -26,6 +26,8 @@
#include <linux/async.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>
+#include <linux/ramfs.h>
+#include <linux/shmem_fs.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
@@ -588,3 +590,46 @@ out:
sys_mount(".", "/", NULL, MS_MOVE, NULL);
sys_chroot(".");
}
+
+static bool is_tmpfs;
+static struct dentry *rootfs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ static unsigned long once;
+ void *fill = ramfs_fill_super;
+
+ if (test_and_set_bit(0, &once))
+ return ERR_PTR(-ENODEV);
+
+ if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
+ fill = shmem_fill_super;
+
+ return mount_nodev(fs_type, flags, data, fill);
+}
+
+static struct file_system_type rootfs_fs_type = {
+ .name = "rootfs",
+ .mount = rootfs_mount,
+ .kill_sb = kill_litter_super,
+};
+
+int __init init_rootfs(void)
+{
+ int err = register_filesystem(&rootfs_fs_type);
+
+ if (err)
+ return err;
+
+ if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
+ (!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
+ err = shmem_init();
+ is_tmpfs = true;
+ } else {
+ err = init_ramfs_fs();
+ }
+
+ if (err)
+ unregister_filesystem(&rootfs_fs_type);
+
+ return err;
+}
diff --git a/init/main.c b/init/main.c
index 586cd3359c02..63d3e8f2970c 100644
--- a/init/main.c
+++ b/init/main.c
@@ -75,6 +75,7 @@
#include <linux/blkdev.h>
#include <linux/elevator.h>
#include <linux/sched_clock.h>
+#include <linux/context_tracking.h>
#include <linux/random.h>
#include <asm/io.h>
@@ -546,6 +547,7 @@ asmlinkage void __init start_kernel(void)
idr_init_cache();
rcu_init();
tick_nohz_init();
+ context_tracking_init();
radix_tree_init();
/* init some links before init_ISA_irqs() */
early_irq_init();