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-rw-r--r--init/Kconfig47
-rw-r--r--init/do_mounts.c70
-rw-r--r--init/main.c3
3 files changed, 109 insertions, 11 deletions
diff --git a/init/Kconfig b/init/Kconfig
index d742b6fca8d..fdfd97efe0e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -21,6 +21,13 @@ config CONSTRUCTORS
depends on !UML
default y
+config HAVE_IRQ_WORK
+ bool
+
+config IRQ_WORK
+ bool
+ depends on HAVE_IRQ_WORK
+
menu "General setup"
config EXPERIMENTAL
@@ -64,7 +71,7 @@ config BROKEN_ON_SMP
config LOCK_KERNEL
bool
- depends on SMP || PREEMPT
+ depends on (SMP || PREEMPT) && BKL
default y
config INIT_ENV_ARG_LIMIT
@@ -332,6 +339,8 @@ config AUDIT_TREE
depends on AUDITSYSCALL
select FSNOTIFY
+source "kernel/irq/Kconfig"
+
menu "RCU Subsystem"
choice
@@ -340,6 +349,7 @@ choice
config TREE_RCU
bool "Tree-based hierarchical RCU"
+ depends on !PREEMPT && SMP
help
This option selects the RCU implementation that is
designed for very large SMP system with hundreds or
@@ -347,7 +357,7 @@ config TREE_RCU
smaller systems.
config TREE_PREEMPT_RCU
- bool "Preemptable tree-based hierarchical RCU"
+ bool "Preemptible tree-based hierarchical RCU"
depends on PREEMPT
help
This option selects the RCU implementation that is
@@ -365,8 +375,22 @@ config TINY_RCU
is not required. This option greatly reduces the
memory footprint of RCU.
+config TINY_PREEMPT_RCU
+ bool "Preemptible UP-only small-memory-footprint RCU"
+ depends on !SMP && PREEMPT
+ help
+ This option selects the RCU implementation that is designed
+ for real-time UP systems. This option greatly reduces the
+ memory footprint of RCU.
+
endchoice
+config PREEMPT_RCU
+ def_bool ( TREE_PREEMPT_RCU || TINY_PREEMPT_RCU )
+ help
+ This option enables preemptible-RCU code that is common between
+ the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
+
config RCU_TRACE
bool "Enable tracing for RCU"
depends on TREE_RCU || TREE_PREEMPT_RCU
@@ -387,9 +411,12 @@ config RCU_FANOUT
help
This option controls the fanout of hierarchical implementations
of RCU, allowing RCU to work efficiently on machines with
- large numbers of CPUs. This value must be at least the cube
- root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
- systems and up to 262,144 for 64-bit systems.
+ large numbers of CPUs. This value must be at least the fourth
+ root of NR_CPUS, which allows NR_CPUS to be insanely large.
+ The default value of RCU_FANOUT should be used for production
+ systems, but if you are stress-testing the RCU implementation
+ itself, small RCU_FANOUT values allow you to test large-system
+ code paths on small(er) systems.
Select a specific number if testing RCU itself.
Take the default if unsure.
@@ -634,11 +661,14 @@ config BLK_CGROUP
Currently, CFQ IO scheduler uses it to recognize task groups and
control disk bandwidth allocation (proportional time slice allocation)
- to such task groups.
+ to such task groups. It is also used by bio throttling logic in
+ block layer to implement upper limit in IO rates on a device.
This option only enables generic Block IO controller infrastructure.
- One needs to also enable actual IO controlling logic in CFQ for it
- to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y).
+ One needs to also enable actual IO controlling logic/policy. For
+ enabling proportional weight division of disk bandwidth in CFQ seti
+ CONFIG_CFQ_GROUP_IOSCHED=y and for enabling throttling policy set
+ CONFIG_BLK_THROTTLE=y.
See Documentation/cgroups/blkio-controller.txt for more information.
@@ -989,6 +1019,7 @@ config PERF_EVENTS
default y if (PROFILING || PERF_COUNTERS)
depends on HAVE_PERF_EVENTS
select ANON_INODES
+ select IRQ_WORK
help
Enable kernel support for various performance events provided
by software and hardware.
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 02e3ca4fc52..42db0551c3a 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -58,6 +58,62 @@ static int __init readwrite(char *str)
__setup("ro", readonly);
__setup("rw", readwrite);
+#ifdef CONFIG_BLOCK
+/**
+ * match_dev_by_uuid - callback for finding a partition using its uuid
+ * @dev: device passed in by the caller
+ * @data: opaque pointer to a 36 byte char array with a UUID
+ *
+ * Returns 1 if the device matches, and 0 otherwise.
+ */
+static int match_dev_by_uuid(struct device *dev, void *data)
+{
+ u8 *uuid = data;
+ struct hd_struct *part = dev_to_part(dev);
+
+ if (!part->info)
+ goto no_match;
+
+ if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid)))
+ goto no_match;
+
+ return 1;
+no_match:
+ return 0;
+}
+
+
+/**
+ * devt_from_partuuid - looks up the dev_t of a partition by its UUID
+ * @uuid: 36 byte char array containing a hex ascii UUID
+ *
+ * The function will return the first partition which contains a matching
+ * UUID value in its partition_meta_info struct. This does not search
+ * by filesystem UUIDs.
+ *
+ * Returns the matching dev_t on success or 0 on failure.
+ */
+static dev_t __init devt_from_partuuid(char *uuid_str)
+{
+ dev_t res = 0;
+ struct device *dev = NULL;
+ u8 uuid[16];
+
+ /* Pack the requested UUID in the expected format. */
+ part_pack_uuid(uuid_str, uuid);
+
+ dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid);
+ if (!dev)
+ goto done;
+
+ res = dev->devt;
+ put_device(dev);
+
+done:
+ return res;
+}
+#endif
+
/*
* Convert a name into device number. We accept the following variants:
*
@@ -68,6 +124,8 @@ __setup("rw", readwrite);
* of partition - device number of disk plus the partition number
* 5) /dev/<disk_name>p<decimal> - same as the above, that form is
* used when disk name of partitioned disk ends on a digit.
+ * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
+ * unique id of a partition if the partition table provides it.
*
* If name doesn't have fall into the categories above, we return (0,0).
* block_class is used to check if something is a disk name. If the disk
@@ -82,6 +140,18 @@ dev_t name_to_dev_t(char *name)
dev_t res = 0;
int part;
+#ifdef CONFIG_BLOCK
+ if (strncmp(name, "PARTUUID=", 9) == 0) {
+ name += 9;
+ if (strlen(name) != 36)
+ goto fail;
+ res = devt_from_partuuid(name);
+ if (!res)
+ goto fail;
+ goto done;
+ }
+#endif
+
if (strncmp(name, "/dev/", 5) != 0) {
unsigned maj, min;
diff --git a/init/main.c b/init/main.c
index 94ab488039a..e59af24a0b7 100644
--- a/init/main.c
+++ b/init/main.c
@@ -424,7 +424,6 @@ static void __init setup_command_line(char *command_line)
static __initdata DECLARE_COMPLETION(kthreadd_done);
static noinline void __init_refok rest_init(void)
- __releases(kernel_lock)
{
int pid;
@@ -556,7 +555,6 @@ asmlinkage void __init start_kernel(void)
local_irq_disable();
early_boot_irqs_off();
- early_init_irq_lock_class();
/*
* Interrupts are still disabled. Do necessary setups, then
@@ -819,7 +817,6 @@ static void run_init_process(const char *init_filename)
* makes it inline to init() and it becomes part of init.text section
*/
static noinline int init_post(void)
- __releases(kernel_lock)
{
/* need to finish all async __init code before freeing the memory */
async_synchronize_full();