[ANNOUNCE] 3.4-rt8

From: Thomas Gleixner
Date: Mon Jun 04 2012 - 11:50:18 EST


Dear RT Folks,

I'm pleased to announce the 3.4-rt8 release.

Changes since 3.4-rt7:

* Printk fix (Frank Rowand)

* mm activate protection fix (Frank Rowand)

* qla2xxx rt conversion (John Kacur)

* Networking RT fix (Priyanka Jain)

* Lockdep selftest fixes (Yong Zhang)

* Mips remove smp_reserve_lock

* genirq: Add default irq mask command line parameter

This is the last 3.4-rt release from my side. I'm handing 3.4 over to
Steven and move on to 3.5.

The delta patch to 3.4-rt7 is appended below and can be found
here as incremental patch:

http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/incr/patch-3.4-rt7-rt8.patch.xz

The RT patch against 3.4 can be found here:

http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/patch-3.4-rt8.patch.xz


The split quilt queue is available at:

http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/patches-3.4-rt8.tar.xz


Enjoy,

tglx
---
Index: linux-3.4/drivers/tty/serial/cpm_uart/cpm_uart_core.c
===================================================================
--- linux-3.4.orig/drivers/tty/serial/cpm_uart/cpm_uart_core.c
+++ linux-3.4/drivers/tty/serial/cpm_uart/cpm_uart_core.c
@@ -1226,7 +1226,7 @@ static void cpm_uart_console_write(struc
{
struct uart_cpm_port *pinfo = &cpm_uart_ports[co->index];
unsigned long flags;
- int nolock = oops_in_progress || sysrq_in_progress;
+ int nolock = oops_in_progress;

if (unlikely(nolock)) {
local_irq_save(flags);
Index: linux-3.4/drivers/tty/sysrq.c
===================================================================
--- linux-3.4.orig/drivers/tty/sysrq.c
+++ linux-3.4/drivers/tty/sysrq.c
@@ -495,23 +495,6 @@ static void __sysrq_put_key_op(int key,
sysrq_key_table[i] = op_p;
}

-#ifdef CONFIG_MAGIC_SYSRQ_FORCE_PRINTK
-
-int sysrq_in_progress;
-
-static void set_sysrq_in_progress(int value)
-{
- sysrq_in_progress = value;
-}
-
-#else
-
-static void set_sysrq_in_progress(int value)
-{
-}
-
-#endif
-
void __handle_sysrq(int key, bool check_mask)
{
struct sysrq_key_op *op_p;
@@ -520,9 +503,6 @@ void __handle_sysrq(int key, bool check_
unsigned long flags;

spin_lock_irqsave(&sysrq_key_table_lock, flags);
-
- set_sysrq_in_progress(1);
-
/*
* Raise the apparent loglevel to maximum so that the sysrq header
* is shown to provide the user with positive feedback. We do not
@@ -564,9 +544,6 @@ void __handle_sysrq(int key, bool check_
printk("\n");
console_loglevel = orig_log_level;
}
-
- set_sysrq_in_progress(0);
-
spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
}

Index: linux-3.4/fs/exec.c
===================================================================
--- linux-3.4.orig/fs/exec.c
+++ linux-3.4/fs/exec.c
@@ -840,12 +840,12 @@ static int exec_mmap(struct mm_struct *m
}
}
task_lock(tsk);
- local_irq_disable_rt();
+ preempt_disable_rt();
active_mm = tsk->active_mm;
tsk->mm = mm;
tsk->active_mm = mm;
activate_mm(active_mm, mm);
- local_irq_enable_rt();
+ preempt_enable_rt();
task_unlock(tsk);
arch_pick_mmap_layout(mm);
if (old_mm) {
Index: linux-3.4/include/linux/sysrq.h
===================================================================
--- linux-3.4.orig/include/linux/sysrq.h
+++ linux-3.4/include/linux/sysrq.h
@@ -38,11 +38,6 @@ struct sysrq_key_op {
int enable_mask;
};

-#ifdef CONFIG_MAGIC_SYSRQ_FORCE_PRINTK
-extern int sysrq_in_progress;
-#else
-#define sysrq_in_progress 0
-#endif
#ifdef CONFIG_MAGIC_SYSRQ

/* Generic SysRq interface -- you may call it from any device driver, supplying
Index: linux-3.4/kernel/printk.c
===================================================================
--- linux-3.4.orig/kernel/printk.c
+++ linux-3.4/kernel/printk.c
@@ -21,7 +21,6 @@
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/console.h>
-#include <linux/sysrq.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/nmi.h>
@@ -847,8 +846,8 @@ static int console_trylock_for_printk(un
{
int retval = 0, wake = 0;
#ifdef CONFIG_PREEMPT_RT_FULL
- int lock = (!early_boot_irqs_disabled && !irqs_disabled_flags(flags) &&
- !preempt_count()) || sysrq_in_progress;
+ int lock = !early_boot_irqs_disabled && !irqs_disabled_flags(flags) &&
+ (preempt_count() <= 1);
#else
int lock = 1;
#endif
Index: linux-3.4/kernel/time/tick-sched.c
===================================================================
--- linux-3.4.orig/kernel/time/tick-sched.c
+++ linux-3.4/kernel/time/tick-sched.c
@@ -812,6 +812,16 @@ static enum hrtimer_restart tick_sched_t
return HRTIMER_RESTART;
}

+static int sched_skew_tick;
+
+static int __init skew_tick(char *str)
+{
+ get_option(&str, &sched_skew_tick);
+
+ return 0;
+}
+early_param("skew_tick", skew_tick);
+
/**
* tick_setup_sched_timer - setup the tick emulation timer
*/
@@ -830,6 +840,14 @@ void tick_setup_sched_timer(void)
/* Get the next period (per cpu) */
hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());

+ /* Offset the tick to avert xtime_lock contention. */
+ if (sched_skew_tick) {
+ u64 offset = ktime_to_ns(tick_period) >> 1;
+ do_div(offset, num_possible_cpus());
+ offset *= smp_processor_id();
+ hrtimer_add_expires_ns(&ts->sched_timer, offset);
+ }
+
for (;;) {
hrtimer_forward(&ts->sched_timer, now, tick_period);
hrtimer_start_expires(&ts->sched_timer,
Index: linux-3.4/lib/Kconfig.debug
===================================================================
--- linux-3.4.orig/lib/Kconfig.debug
+++ linux-3.4/lib/Kconfig.debug
@@ -62,28 +62,6 @@ config MAGIC_SYSRQ
keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
unless you really know what this hack does.

-config MAGIC_SYSRQ_FORCE_PRINTK
- bool "Force printk from Magic SysRq"
- depends on MAGIC_SYSRQ && PREEMPT_RT_FULL
- default n
- help
- Allow the output from Magic SysRq to be output immediately, even if
- this causes large latencies. This can cause performance problems
- for real-time processes.
-
- If PREEMPT_RT_FULL, printk() will not try to acquire the console lock
- when interrupts or preemption are disabled. If the console lock is
- not acquired the printk() output will be buffered, but will not be
- output immediately. Some drivers call into the Magic SysRq code
- with interrupts or preemption disabled, so the output of Magic SysRq
- will be buffered instead of printing immediately if this option is
- not selected.
-
- Even with this option selected, Magic SysRq output will be delayed
- if the attempt to acquire the console lock fails.
-
- Don't say Y unless you really know what this hack does.
-
config STRIP_ASM_SYMS
bool "Strip assembler-generated symbols during link"
default n
Index: linux-3.4/localversion-rt
===================================================================
--- linux-3.4.orig/localversion-rt
+++ linux-3.4/localversion-rt
@@ -1 +1 @@
--rt7
+-rt8
Index: linux-3.4/mm/mmu_context.c
===================================================================
--- linux-3.4.orig/mm/mmu_context.c
+++ linux-3.4/mm/mmu_context.c
@@ -26,7 +26,7 @@ void use_mm(struct mm_struct *mm)
struct task_struct *tsk = current;

task_lock(tsk);
- local_irq_disable_rt();
+ preempt_disable_rt();
active_mm = tsk->active_mm;
if (active_mm != mm) {
atomic_inc(&mm->mm_count);
@@ -34,7 +34,7 @@ void use_mm(struct mm_struct *mm)
}
tsk->mm = mm;
switch_mm(active_mm, mm, tsk);
- local_irq_enable_rt();
+ preempt_enable_rt();
task_unlock(tsk);

if (active_mm != mm)
Index: linux-3.4/net/core/dev.c
===================================================================
--- linux-3.4.orig/net/core/dev.c
+++ linux-3.4/net/core/dev.c
@@ -2937,7 +2937,7 @@ int netif_rx(struct sk_buff *skb)
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu;

- preempt_disable();
+ migrate_disable();
rcu_read_lock();

cpu = get_rps_cpu(skb->dev, skb, &rflow);
@@ -2947,13 +2947,13 @@ int netif_rx(struct sk_buff *skb)
ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);

rcu_read_unlock();
- preempt_enable();
+ migrate_enable();
} else
#endif
{
unsigned int qtail;
- ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
- put_cpu();
+ ret = enqueue_to_backlog(skb, get_cpu_light(), &qtail);
+ put_cpu_light();
}
return ret;
}
Index: linux-3.4/Documentation/kernel-parameters.txt
===================================================================
--- linux-3.4.orig/Documentation/kernel-parameters.txt
+++ linux-3.4/Documentation/kernel-parameters.txt
@@ -1126,6 +1126,15 @@ bytes respectively. Such letter suffixes
See comment before ip2_setup() in
drivers/char/ip2/ip2base.c.

+ irqaffinity= [SMP] Set the default irq affinity mask
+ Format:
+ <cpu number>,...,<cpu number>
+ or
+ <cpu number>-<cpu number>
+ (must be a positive range in ascending order)
+ or a mixture
+ <cpu number>,...,<cpu number>-<cpu number>
+
irqfixup [HW]
When an interrupt is not handled search all handlers
for it. Intended to get systems with badly broken
@@ -2426,6 +2435,15 @@ bytes respectively. Such letter suffixes

sched_debug [KNL] Enables verbose scheduler debug messages.

+ skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate
+ xtime_lock contention on larger systems, and/or RCU lock
+ contention on all systems with CONFIG_MAXSMP set.
+ Format: { "0" | "1" }
+ 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
+ 1 -- enable.
+ Note: increases power consumption, thus should only be
+ enabled if running jitter sensitive (HPC/RT) workloads.
+
security= [SECURITY] Choose a security module to enable at boot.
If this boot parameter is not specified, only the first
security module asking for security registration will be
Index: linux-3.4/drivers/scsi/qla2xxx/qla_inline.h
===================================================================
--- linux-3.4.orig/drivers/scsi/qla2xxx/qla_inline.h
+++ linux-3.4/drivers/scsi/qla2xxx/qla_inline.h
@@ -36,12 +36,12 @@ qla2x00_poll(struct rsp_que *rsp)
{
unsigned long flags;
struct qla_hw_data *ha = rsp->hw;
- local_irq_save(flags);
+ local_irq_save_nort(flags);
if (IS_QLA82XX(ha))
qla82xx_poll(0, rsp);
else
ha->isp_ops->intr_handler(0, rsp);
- local_irq_restore(flags);
+ local_irq_restore_nort(flags);
}

static inline uint8_t *
Index: linux-3.4/arch/mips/cavium-octeon/smp.c
===================================================================
--- linux-3.4.orig/arch/mips/cavium-octeon/smp.c
+++ linux-3.4/arch/mips/cavium-octeon/smp.c
@@ -257,8 +257,6 @@ DEFINE_PER_CPU(int, cpu_state);

extern void fixup_irqs(void);

-static DEFINE_SPINLOCK(smp_reserve_lock);
-
static int octeon_cpu_disable(void)
{
unsigned int cpu = smp_processor_id();
@@ -266,8 +264,6 @@ static int octeon_cpu_disable(void)
if (cpu == 0)
return -EBUSY;

- spin_lock(&smp_reserve_lock);
-
set_cpu_online(cpu, false);
cpu_clear(cpu, cpu_callin_map);
local_irq_disable();
@@ -277,8 +273,6 @@ static int octeon_cpu_disable(void)
flush_cache_all();
local_flush_tlb_all();

- spin_unlock(&smp_reserve_lock);
-
return 0;
}

Index: linux-3.4/lib/locking-selftest.c
===================================================================
--- linux-3.4.orig/lib/locking-selftest.c
+++ linux-3.4/lib/locking-selftest.c
@@ -47,10 +47,10 @@ __setup("debug_locks_verbose=", setup_de
* Normal standalone locks, for the circular and irq-context
* dependency tests:
*/
-static DEFINE_SPINLOCK(lock_A);
-static DEFINE_SPINLOCK(lock_B);
-static DEFINE_SPINLOCK(lock_C);
-static DEFINE_SPINLOCK(lock_D);
+static DEFINE_RAW_SPINLOCK(lock_A);
+static DEFINE_RAW_SPINLOCK(lock_B);
+static DEFINE_RAW_SPINLOCK(lock_C);
+static DEFINE_RAW_SPINLOCK(lock_D);

static DEFINE_RWLOCK(rwlock_A);
static DEFINE_RWLOCK(rwlock_B);
@@ -73,12 +73,12 @@ static DECLARE_RWSEM(rwsem_D);
* but X* and Y* are different classes. We do this so that
* we do not trigger a real lockup:
*/
-static DEFINE_SPINLOCK(lock_X1);
-static DEFINE_SPINLOCK(lock_X2);
-static DEFINE_SPINLOCK(lock_Y1);
-static DEFINE_SPINLOCK(lock_Y2);
-static DEFINE_SPINLOCK(lock_Z1);
-static DEFINE_SPINLOCK(lock_Z2);
+static DEFINE_RAW_SPINLOCK(lock_X1);
+static DEFINE_RAW_SPINLOCK(lock_X2);
+static DEFINE_RAW_SPINLOCK(lock_Y1);
+static DEFINE_RAW_SPINLOCK(lock_Y2);
+static DEFINE_RAW_SPINLOCK(lock_Z1);
+static DEFINE_RAW_SPINLOCK(lock_Z2);

static DEFINE_RWLOCK(rwlock_X1);
static DEFINE_RWLOCK(rwlock_X2);
@@ -107,10 +107,10 @@ static DECLARE_RWSEM(rwsem_Z2);
*/
#define INIT_CLASS_FUNC(class) \
static noinline void \
-init_class_##class(spinlock_t *lock, rwlock_t *rwlock, struct mutex *mutex, \
- struct rw_semaphore *rwsem) \
+init_class_##class(raw_spinlock_t *lock, rwlock_t *rwlock, \
+ struct mutex *mutex, struct rw_semaphore *rwsem)\
{ \
- spin_lock_init(lock); \
+ raw_spin_lock_init(lock); \
rwlock_init(rwlock); \
mutex_init(mutex); \
init_rwsem(rwsem); \
@@ -168,10 +168,10 @@ static void init_shared_classes(void)
* Shortcuts for lock/unlock API variants, to keep
* the testcases compact:
*/
-#define L(x) spin_lock(&lock_##x)
-#define U(x) spin_unlock(&lock_##x)
+#define L(x) raw_spin_lock(&lock_##x)
+#define U(x) raw_spin_unlock(&lock_##x)
#define LU(x) L(x); U(x)
-#define SI(x) spin_lock_init(&lock_##x)
+#define SI(x) raw_spin_lock_init(&lock_##x)

#define WL(x) write_lock(&rwlock_##x)
#define WU(x) write_unlock(&rwlock_##x)
@@ -911,7 +911,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_

#define I2(x) \
do { \
- spin_lock_init(&lock_##x); \
+ raw_spin_lock_init(&lock_##x); \
rwlock_init(&rwlock_##x); \
mutex_init(&mutex_##x); \
init_rwsem(&rwsem_##x); \
@@ -1175,6 +1175,7 @@ void locking_selftest(void)

printk(" --------------------------------------------------------------------------\n");

+#ifndef CONFIG_PREEMPT_RT_FULL
/*
* irq-context testcases:
*/
@@ -1187,6 +1188,28 @@ void locking_selftest(void)

DO_TESTCASE_6x2("irq read-recursion", irq_read_recursion);
// DO_TESTCASE_6x2B("irq read-recursion #2", irq_read_recursion2);
+#else
+ /* On -rt, we only do hardirq context test for raw spinlock */
+ DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 12);
+ DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 21);
+
+ DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 12);
+ DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 21);
+
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 123);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 132);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 213);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 231);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 312);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 321);
+
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 123);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 132);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 213);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 231);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 312);
+ DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 321);
+#endif

if (unexpected_testcase_failures) {
printk("-----------------------------------------------------------------\n");
Index: linux-3.4/kernel/irq/irqdesc.c
===================================================================
--- linux-3.4.orig/kernel/irq/irqdesc.c
+++ linux-3.4/kernel/irq/irqdesc.c
@@ -23,10 +23,27 @@
static struct lock_class_key irq_desc_lock_class;

#if defined(CONFIG_SMP)
+static int __init irq_affinity_setup(char *str)
+{
+ zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+ cpulist_parse(str, irq_default_affinity);
+ /*
+ * Set at least the boot cpu. We don't want to end up with
+ * bugreports caused by random comandline masks
+ */
+ cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
+ return 1;
+}
+__setup("irqaffinity=", irq_affinity_setup);
+
static void __init init_irq_default_affinity(void)
{
- alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
- cpumask_setall(irq_default_affinity);
+#ifdef CONFIG_CPUMASK_OFFSTACK
+ if (!irq_default_affinity)
+ zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+#endif
+ if (cpumask_empty(irq_default_affinity))
+ cpumask_setall(irq_default_affinity);
}
#else
static void __init init_irq_default_affinity(void)
--
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