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-rw-r--r--init/Kconfig75
-rw-r--r--init/calibrate.c6
-rw-r--r--init/main.c13
3 files changed, 48 insertions, 46 deletions
diff --git a/init/Kconfig b/init/Kconfig
index cb0b2051bbb..3da09dab537 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -515,21 +515,6 @@ config RCU_BOOST_DELAY
Accept the default if unsure.
-config SRCU_SYNCHRONIZE_DELAY
- int "Microseconds to delay before waiting for readers"
- range 0 20
- default 10
- help
- This option controls how long SRCU delays before entering its
- loop waiting on SRCU readers. The purpose of this loop is
- to avoid the unconditional context-switch penalty that would
- otherwise be incurred if there was an active SRCU reader,
- in a manner similar to adaptive locking schemes. This should
- be set to be a bit longer than the common-case SRCU read-side
- critical-section overhead.
-
- Accept the default if unsure.
-
endmenu # "RCU Subsystem"
config IKCONFIG
@@ -760,8 +745,8 @@ config DEBUG_BLK_CGROUP
endif # CGROUPS
menuconfig NAMESPACES
- bool "Namespaces support" if EMBEDDED
- default !EMBEDDED
+ bool "Namespaces support" if EXPERT
+ default !EXPERT
help
Provides the way to make tasks work with different objects using
the same id. For example same IPC id may refer to different objects
@@ -914,23 +899,31 @@ config SYSCTL
config ANON_INODES
bool
-menuconfig EMBEDDED
- bool "Configure standard kernel features (for small systems)"
+menuconfig EXPERT
+ bool "Configure standard kernel features (expert users)"
help
This option allows certain base kernel options and settings
to be disabled or tweaked. This is for specialized
environments which can tolerate a "non-standard" kernel.
Only use this if you really know what you are doing.
+config EMBEDDED
+ bool "Embedded system"
+ select EXPERT
+ help
+ This option should be enabled if compiling the kernel for
+ an embedded system so certain expert options are available
+ for configuration.
+
config UID16
- bool "Enable 16-bit UID system calls" if EMBEDDED
+ bool "Enable 16-bit UID system calls" if EXPERT
depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
default y
help
This enables the legacy 16-bit UID syscall wrappers.
config SYSCTL_SYSCALL
- bool "Sysctl syscall support" if EMBEDDED
+ bool "Sysctl syscall support" if EXPERT
depends on PROC_SYSCTL
default y
select SYSCTL
@@ -947,7 +940,7 @@ config SYSCTL_SYSCALL
If unsure say Y here.
config KALLSYMS
- bool "Load all symbols for debugging/ksymoops" if EMBEDDED
+ bool "Load all symbols for debugging/ksymoops" if EXPERT
default y
help
Say Y here to let the kernel print out symbolic crash information and
@@ -978,7 +971,7 @@ config KALLSYMS_EXTRA_PASS
config HOTPLUG
- bool "Support for hot-pluggable devices" if EMBEDDED
+ bool "Support for hot-pluggable devices" if EXPERT
default y
help
This option is provided for the case where no hotplug or uevent
@@ -988,7 +981,7 @@ config HOTPLUG
config PRINTK
default y
- bool "Enable support for printk" if EMBEDDED
+ bool "Enable support for printk" if EXPERT
help
This option enables normal printk support. Removing it
eliminates most of the message strings from the kernel image
@@ -997,7 +990,7 @@ config PRINTK
strongly discouraged.
config BUG
- bool "BUG() support" if EMBEDDED
+ bool "BUG() support" if EXPERT
default y
help
Disabling this option eliminates support for BUG and WARN, reducing
@@ -1008,12 +1001,12 @@ config BUG
config ELF_CORE
default y
- bool "Enable ELF core dumps" if EMBEDDED
+ bool "Enable ELF core dumps" if EXPERT
help
Enable support for generating core dumps. Disabling saves about 4k.
config PCSPKR_PLATFORM
- bool "Enable PC-Speaker support" if EMBEDDED
+ bool "Enable PC-Speaker support" if EXPERT
depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
default y
help
@@ -1022,14 +1015,14 @@ config PCSPKR_PLATFORM
config BASE_FULL
default y
- bool "Enable full-sized data structures for core" if EMBEDDED
+ bool "Enable full-sized data structures for core" if EXPERT
help
Disabling this option reduces the size of miscellaneous core
kernel data structures. This saves memory on small machines,
but may reduce performance.
config FUTEX
- bool "Enable futex support" if EMBEDDED
+ bool "Enable futex support" if EXPERT
default y
select RT_MUTEXES
help
@@ -1038,7 +1031,7 @@ config FUTEX
run glibc-based applications correctly.
config EPOLL
- bool "Enable eventpoll support" if EMBEDDED
+ bool "Enable eventpoll support" if EXPERT
default y
select ANON_INODES
help
@@ -1046,7 +1039,7 @@ config EPOLL
support for epoll family of system calls.
config SIGNALFD
- bool "Enable signalfd() system call" if EMBEDDED
+ bool "Enable signalfd() system call" if EXPERT
select ANON_INODES
default y
help
@@ -1056,7 +1049,7 @@ config SIGNALFD
If unsure, say Y.
config TIMERFD
- bool "Enable timerfd() system call" if EMBEDDED
+ bool "Enable timerfd() system call" if EXPERT
select ANON_INODES
default y
help
@@ -1066,7 +1059,7 @@ config TIMERFD
If unsure, say Y.
config EVENTFD
- bool "Enable eventfd() system call" if EMBEDDED
+ bool "Enable eventfd() system call" if EXPERT
select ANON_INODES
default y
help
@@ -1076,7 +1069,7 @@ config EVENTFD
If unsure, say Y.
config SHMEM
- bool "Use full shmem filesystem" if EMBEDDED
+ bool "Use full shmem filesystem" if EXPERT
default y
depends on MMU
help
@@ -1087,7 +1080,7 @@ config SHMEM
which may be appropriate on small systems without swap.
config AIO
- bool "Enable AIO support" if EMBEDDED
+ bool "Enable AIO support" if EXPERT
default y
help
This option enables POSIX asynchronous I/O which may by used
@@ -1164,16 +1157,16 @@ endmenu
config VM_EVENT_COUNTERS
default y
- bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
+ bool "Enable VM event counters for /proc/vmstat" if EXPERT
help
VM event counters are needed for event counts to be shown.
This option allows the disabling of the VM event counters
- on EMBEDDED systems. /proc/vmstat will only show page counts
+ on EXPERT systems. /proc/vmstat will only show page counts
if VM event counters are disabled.
config PCI_QUIRKS
default y
- bool "Enable PCI quirk workarounds" if EMBEDDED
+ bool "Enable PCI quirk workarounds" if EXPERT
depends on PCI
help
This enables workarounds for various PCI chipset
@@ -1182,7 +1175,7 @@ config PCI_QUIRKS
config SLUB_DEBUG
default y
- bool "Enable SLUB debugging support" if EMBEDDED
+ bool "Enable SLUB debugging support" if EXPERT
depends on SLUB && SYSFS
help
SLUB has extensive debug support features. Disabling these can
@@ -1226,7 +1219,7 @@ config SLUB
a slab allocator.
config SLOB
- depends on EMBEDDED
+ depends on EXPERT
bool "SLOB (Simple Allocator)"
help
SLOB replaces the stock allocator with a drastically simpler
@@ -1237,7 +1230,7 @@ endchoice
config MMAP_ALLOW_UNINITIALIZED
bool "Allow mmapped anonymous memory to be uninitialized"
- depends on EMBEDDED && !MMU
+ depends on EXPERT && !MMU
default n
help
Normally, and according to the Linux spec, anonymous memory obtained
diff --git a/init/calibrate.c b/init/calibrate.c
index 6eb48e53d61..24fe022c55f 100644
--- a/init/calibrate.c
+++ b/init/calibrate.c
@@ -66,7 +66,7 @@ static unsigned long __cpuinit calibrate_delay_direct(void)
pre_start = 0;
read_current_timer(&start);
start_jiffies = jiffies;
- while (jiffies <= (start_jiffies + 1)) {
+ while (time_before_eq(jiffies, start_jiffies + 1)) {
pre_start = start;
read_current_timer(&start);
}
@@ -74,8 +74,8 @@ static unsigned long __cpuinit calibrate_delay_direct(void)
pre_end = 0;
end = post_start;
- while (jiffies <=
- (start_jiffies + 1 + DELAY_CALIBRATION_TICKS)) {
+ while (time_before_eq(jiffies, start_jiffies + 1 +
+ DELAY_CALIBRATION_TICKS)) {
pre_end = end;
read_current_timer(&end);
}
diff --git a/init/main.c b/init/main.c
index 00799c1d462..33c37c379e9 100644
--- a/init/main.c
+++ b/init/main.c
@@ -96,6 +96,15 @@ static inline void mark_rodata_ro(void) { }
extern void tc_init(void);
#endif
+/*
+ * Debug helper: via this flag we know that we are in 'early bootup code'
+ * where only the boot processor is running with IRQ disabled. This means
+ * two things - IRQ must not be enabled before the flag is cleared and some
+ * operations which are not allowed with IRQ disabled are allowed while the
+ * flag is set.
+ */
+bool early_boot_irqs_disabled __read_mostly;
+
enum system_states system_state __read_mostly;
EXPORT_SYMBOL(system_state);
@@ -554,7 +563,7 @@ asmlinkage void __init start_kernel(void)
cgroup_init_early();
local_irq_disable();
- early_boot_irqs_off();
+ early_boot_irqs_disabled = true;
/*
* Interrupts are still disabled. Do necessary setups, then
@@ -621,7 +630,7 @@ asmlinkage void __init start_kernel(void)
if (!irqs_disabled())
printk(KERN_CRIT "start_kernel(): bug: interrupts were "
"enabled early\n");
- early_boot_irqs_on();
+ early_boot_irqs_disabled = false;
local_irq_enable();
/* Interrupts are enabled now so all GFP allocations are safe. */