3.4.15-rt26-rc1 stable review
Subsystems (2)
cover 3.4.15-rt26-rc1 stable review
Dear RT Folks,
This is the RT stable review cycle of patch 3.4.15-rt26-rc1.
Please scream at me if I messed something up. Please test the patches too.
The -rc release will be uploaded to kernel.org and will be deleted when the final release is out. This is just a review release (or release candidate).
The pre-releases will not be pushed to the git repository, only the final release is.
If all goes well, this patch will be converted to the next main release on 11/2/2012.
Enjoy,
-- Steve
To build 3.4.15-rt26-rc1 directly, the following patches should be applied:
http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.4.tar.xz
http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.4.15.xz
http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/patch-3.4.15-rt26-rc1.patch.xz
You can also build from 3.4.15-rt25 by applying the incremental patch:
http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/incr/patch-3.4.15-rt25-rt26-rc1.patch.xz
Changes from 3.4.15-rt25:
---
Steven Rostedt (1):
Linux 3.4.15-rt26-rc1
Thomas Gleixner (2):
rcu: Disable RCU_FAST_NO_HZ on RT
net: netfilter: Serialize xt_write_recseq sections on RT
Watanabe (1):
hrtimer: Raise softirq if hrtimer irq stalled
----
include/linux/locallock.h | 4 ++++ include/linux/netfilter/x_tables.h | 7 +++++++ init/Kconfig | 2 +- kernel/hrtimer.c | 9 ++++----- localversion-rt | 2 +- net/netfilter/core.c | 6 ++++++ 6 files changed, 23 insertions(+), 7 deletions(-)
PATCH 1/4 hrtimer: Raise softirq if hrtimer irq stalled
From: Watanabe <[email protected]>
When the hrtimer stall detection hits the softirq is not raised.
--- kernel/hrtimer.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
kernel/hrtimer.c +4 -5
@@ -1527,11 +1527,7 @@ retry:if (expires_next.tv64 ==KTIME_MAX || !tick_program_event (expires_next,0 )) { cpu_base->hang_detected =0 ; - -if (raise) -raise_softirq_irqoff (HRTIMER_SOFTIRQ ); - -return ; + goto out; }/*
@@ -1575,6 +1571,9 @@ retry:tick_program_event (expires_next,1 );printk_once (KERN_WARNING "hrtimer: interrupt took %llu ns\n" ,ktime_to_ns (delta)); +out: +if (raise) +raise_softirq_irqoff (HRTIMER_SOFTIRQ ); }/*
Signature · 1 line
1.7.10.4
PATCH 2/4 rcu: Disable RCU_FAST_NO_HZ on RT
In reply to Steven RostedtFrom: Thomas Gleixner <[email protected]>
This uses a timer_list timer from the irq disabled guts of the idle code. Disable it for now to prevent wreckage.
--- init/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
init/Kconfig +1 -1
@@ -474,7 +474,7 @@ config RCU_FANOUT_EXACT config RCU_FAST_NO_HZ bool "Accelerate last non-dyntick-idle CPU's grace periods" - depends on NO_HZ && SMP + depends on NO_HZ && SMP && !PREEMPT_RT_FULL default n help This option causes RCU to attempt to accelerate grace periods
Signature · 1 line
1.7.10.4
PATCH 3/4 net: netfilter: Serialize xt_write_recseq sections on RT
In reply to Steven RostedtFrom: Thomas Gleixner <[email protected]>
The netfilter code relies only on the implicit semantics of local_bh_disable() for serializing wt_write_recseq sections. RT breaks that and needs explicit serialization here.
--- include/linux/locallock.h | 4 ++++ include/linux/netfilter/x_tables.h | 7 +++++++ net/netfilter/core.c | 6 ++++++ 3 files changed, 17 insertions(+)
include/linux/locallock.h +4 -0
@@ -25,6 +25,9 @@ struct local_irq_lock { DEFINE_PER_CPU(struct local_irq_lock, lvar) = { \ .lock = __SPIN_LOCK_UNLOCKED((lvar).lock) } +#define DECLARE_LOCAL_IRQ_LOCK (lvar) \ + DECLARE_PER_CPU(struct local_irq_lock, lvar) +#define local_irq_lock_init (lvar) \ do { \ int __cpu; \
@@ -220,6 +223,7 @@ static inline int __local_unlock_irqrestore(struct local_irq_lock *lv,#else /* PREEMPT_RT_BASE */ #define DEFINE_LOCAL_IRQ_LOCK (lvar) __typeof__(const int) lvar +#define DECLARE_LOCAL_IRQ_LOCK (lvar) extern __typeof__(const int) lvarstatic inline void local_irq_lock_init (int lvar) { }
include/linux/netfilter/x_tables.h +7 -0
@@ -186,6 +186,7 @@ struct xt_counters_info {#ifdef __KERNEL__#include <linux/netdevice.h> +#include <linux/locallock.h> /** * struct xt_action_param - parameters for matches/targets
@@ -466,6 +467,8 @@ extern void xt_free_table_info(struct xt_table_info *info);*/ DECLARE_PER_CPU (seqcount_t, xt_recseq); +DECLARE_LOCAL_IRQ_LOCK (xt_write_lock); +/** * xt_write_recseq_begin - start of a write section *
@@ -480,6 +483,9 @@ static inline unsigned int xt_write_recseq_begin(void) {unsigned int addend; +/* RT protection */ +local_lock (xt_write_lock); +/* * Low order bit of sequence is set if we already * called xt_write_recseq_begin().
@@ -510,6 +516,7 @@ static inline void xt_write_recseq_end(unsigned int addend)/* this is kind of a write_seqcount_end(), but addend is 0 or 1 */ smp_wmb ();__this_cpu_add (xt_recseq.sequence, addend); +local_unlock (xt_write_lock); }/*
net/netfilter/core.c +6 -0
@@ -20,11 +20,17 @@#include <linux/proc_fs.h> #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/locallock.h> #include <net/net_namespace.h> #include <net/sock.h> #include "nf_internals.h" +#ifdef CONFIG_PREEMPT_RT_BASE +DEFINE_LOCAL_IRQ_LOCK (xt_write_lock); +EXPORT_PER_CPU_SYMBOL (xt_write_lock); +#endif +static DEFINE_MUTEX (afinfo_mutex);const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO ]__read_mostly ;
Signature · 1 line
1.7.10.4
PATCH 4/4 Linux 3.4.15-rt26-rc1
In reply to Steven RostedtFrom: Steven Rostedt <[email protected]>
--- localversion-rt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
localversion-rt +1 -1
@@ -1 +1 @@ --rt25 +-rt26-rc1
Signature · 1 line
1.7.10.4