[ANNOUNCE] 3.4-rc2-rt1
From: Thomas Gleixner
Date: Tue Apr 10 2012 - 10:46:04 EST
Dear RT Folks,
I'm pleased to announce the 3.4-rc2-rt1 release.
This is a straight forward update of the 3.2 series to 3.4-rc2. It's
slightly smaller than the 3.2 series. I hope to stabilize it fast so I
can concentrate on shuffling more parts of RT into 3.5.
The RT patch against 3.4-rc2-rt1 can be found here:
http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/patch-3.4-rc2-rt1.patch.xz
The split quilt queue is available at:
http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/patches-3.4-rc2-rt1.tar.xz
Enjoy,
tglx
---
Index: linux-3.2/fs/autofs4/autofs_i.h
===================================================================
--- linux-3.2.orig/fs/autofs4/autofs_i.h
+++ linux-3.2/fs/autofs4/autofs_i.h
@@ -34,6 +34,7 @@
#include <linux/sched.h>
#include <linux/mount.h>
#include <linux/namei.h>
+#include <linux/delay.h>
#include <asm/current.h>
#include <asm/uaccess.h>
Index: linux-3.2/fs/autofs4/expire.c
===================================================================
--- linux-3.2.orig/fs/autofs4/expire.c
+++ linux-3.2/fs/autofs4/expire.c
@@ -170,7 +170,7 @@ again:
parent = p->d_parent;
if (!seq_spin_trylock(&parent->d_lock)) {
seq_spin_unlock(&p->d_lock);
- cpu_relax();
+ cpu_chill();
goto relock;
}
seq_spin_unlock(&p->d_lock);
Index: linux-3.2/fs/dcache.c
===================================================================
--- linux-3.2.orig/fs/dcache.c
+++ linux-3.2/fs/dcache.c
@@ -37,6 +37,7 @@
#include <linux/rculist_bl.h>
#include <linux/prefetch.h>
#include <linux/ratelimit.h>
+#include <linux/delay.h>
#include "internal.h"
/*
@@ -410,7 +411,7 @@ static inline struct dentry *dentry_kill
if (inode && !spin_trylock(&inode->i_lock)) {
relock:
seq_spin_unlock(&dentry->d_lock);
- cpu_relax();
+ cpu_chill();
return dentry; /* try again with same dentry */
}
if (IS_ROOT(dentry))
@@ -796,7 +797,7 @@ relock:
if (!seq_spin_trylock(&dentry->d_lock)) {
spin_unlock(&dcache_lru_lock);
- cpu_relax();
+ cpu_chill();
goto relock;
}
@@ -1974,7 +1975,7 @@ again:
if (dentry->d_count == 1) {
if (inode && !spin_trylock(&inode->i_lock)) {
seq_spin_unlock(&dentry->d_lock);
- cpu_relax();
+ cpu_chill();
goto again;
}
dentry->d_flags &= ~DCACHE_CANT_MOUNT;
Index: linux-3.2/fs/namespace.c
===================================================================
--- linux-3.2.orig/fs/namespace.c
+++ linux-3.2/fs/namespace.c
@@ -31,6 +31,7 @@
#include <linux/idr.h>
#include <linux/fs_struct.h>
#include <linux/fsnotify.h>
+#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include "pnode.h"
@@ -346,7 +347,7 @@ int mnt_want_write(struct vfsmount *mnt)
*/
while (mnt->mnt_flags & MNT_WRITE_HOLD) {
preempt_enable();
- cpu_relax();
+ cpu_chill();
preempt_disable();
}
/*
Index: linux-3.2/include/linux/preempt.h
===================================================================
--- linux-3.2.orig/include/linux/preempt.h
+++ linux-3.2/include/linux/preempt.h
@@ -56,8 +56,10 @@ do { \
#ifndef CONFIG_PREEMPT_RT_BASE
# define preempt_enable_no_resched() __preempt_enable_no_resched()
+# define preempt_check_resched_rt() do { } while (0)
#else
# define preempt_enable_no_resched() preempt_enable()
+# define preempt_check_resched_rt() preempt_check_resched()
#endif
#define preempt_enable() \
Index: linux-3.2/kernel/irq/manage.c
===================================================================
--- linux-3.2.orig/kernel/irq/manage.c
+++ linux-3.2/kernel/irq/manage.c
@@ -995,6 +995,11 @@ __setup_irq(unsigned int irq, struct irq
/* add new interrupt at end of irq queue */
do {
+ /*
+ * Or all existing action->thread_mask bits,
+ * so we can find the next zero bit for this
+ * new action.
+ */
thread_mask |= old->thread_mask;
old_ptr = &old->next;
old = *old_ptr;
@@ -1003,14 +1008,41 @@ __setup_irq(unsigned int irq, struct irq
}
/*
- * Setup the thread mask for this irqaction. Unlikely to have
- * 32 resp 64 irqs sharing one line, but who knows.
+ * Setup the thread mask for this irqaction for ONESHOT. For
+ * !ONESHOT irqs the thread mask is 0 so we can avoid a
+ * conditional in irq_wake_thread().
*/
- if (new->flags & IRQF_ONESHOT && thread_mask == ~0UL) {
- ret = -EBUSY;
- goto out_mask;
+ if (new->flags & IRQF_ONESHOT) {
+ /*
+ * Unlikely to have 32 resp 64 irqs sharing one line,
+ * but who knows.
+ */
+ if (thread_mask == ~0UL) {
+ ret = -EBUSY;
+ goto out_mask;
+ }
+ /*
+ * The thread_mask for the action is or'ed to
+ * desc->thread_active to indicate that the
+ * IRQF_ONESHOT thread handler has been woken, but not
+ * yet finished. The bit is cleared when a thread
+ * completes. When all threads of a shared interrupt
+ * line have completed desc->threads_active becomes
+ * zero and the interrupt line is unmasked. See
+ * handle.c:irq_wake_thread() for further information.
+ *
+ * If no thread is woken by primary (hard irq context)
+ * interrupt handlers, then desc->threads_active is
+ * also checked for zero to unmask the irq line in the
+ * affected hard irq flow handlers
+ * (handle_[fasteoi|level]_irq).
+ *
+ * The new action gets the first zero bit of
+ * thread_mask assigned. See the loop above which or's
+ * all existing action->thread_mask bits.
+ */
+ new->thread_mask = 1 << ffz(thread_mask);
}
- new->thread_mask = 1 << ffz(thread_mask);
if (!shared) {
init_waitqueue_head(&desc->wait_for_threads);
Index: linux-3.2/localversion-rt
===================================================================
--- linux-3.2.orig/localversion-rt
+++ linux-3.2/localversion-rt
@@ -1 +1 @@
--rt16
+-rt17
Index: linux-3.2/net/core/dev.c
===================================================================
--- linux-3.2.orig/net/core/dev.c
+++ linux-3.2/net/core/dev.c
@@ -1779,6 +1779,7 @@ static inline void __netif_reschedule(st
sd->output_queue_tailp = &q->next_sched;
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
void __netif_schedule(struct Qdisc *q)
@@ -1800,6 +1801,7 @@ void dev_kfree_skb_irq(struct sk_buff *s
sd->completion_queue = skb;
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
}
EXPORT_SYMBOL(dev_kfree_skb_irq);
@@ -2969,6 +2971,7 @@ enqueue:
rps_unlock(sd);
local_irq_restore(flags);
+ preempt_check_resched_rt();
atomic_long_inc(&skb->dev->rx_dropped);
kfree_skb(skb);
@@ -3789,6 +3792,7 @@ static void net_rps_action_and_irq_enabl
} else
#endif
local_irq_enable();
+ preempt_check_resched_rt();
}
static int process_backlog(struct napi_struct *napi, int quota)
@@ -3861,6 +3865,7 @@ void __napi_schedule(struct napi_struct
local_irq_save(flags);
____napi_schedule(&__get_cpu_var(softnet_data), n);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
EXPORT_SYMBOL(__napi_schedule);
@@ -6401,6 +6406,7 @@ static int dev_cpu_callback(struct notif
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
/* Process offline CPU's input_pkt_queue */
while ((skb = __skb_dequeue(&oldsd->process_queue))) {
Index: linux-3.2/block/blk-iopoll.c
===================================================================
--- linux-3.2.orig/block/blk-iopoll.c
+++ linux-3.2/block/blk-iopoll.c
@@ -38,6 +38,7 @@ void blk_iopoll_sched(struct blk_iopoll
list_add_tail(&iop->list, &__get_cpu_var(blk_cpu_iopoll));
__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
EXPORT_SYMBOL(blk_iopoll_sched);
@@ -135,6 +136,7 @@ static void blk_iopoll_softirq(struct so
__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
}
/**
@@ -204,6 +206,7 @@ static int __cpuinit blk_iopoll_cpu_noti
&__get_cpu_var(blk_cpu_iopoll));
__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
}
return NOTIFY_OK;
Index: linux-3.2/block/blk-softirq.c
===================================================================
--- linux-3.2.orig/block/blk-softirq.c
+++ linux-3.2/block/blk-softirq.c
@@ -50,6 +50,7 @@ static void trigger_softirq(void *data)
raise_softirq_irqoff(BLOCK_SOFTIRQ);
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
/*
@@ -92,6 +93,7 @@ static int __cpuinit blk_cpu_notify(stru
&__get_cpu_var(blk_cpu_done));
raise_softirq_irqoff(BLOCK_SOFTIRQ);
local_irq_enable();
+ preempt_check_resched_rt();
}
return NOTIFY_OK;
@@ -150,6 +152,7 @@ do_local:
goto do_local;
local_irq_restore(flags);
+ preempt_check_resched_rt();
}
/**
Index: linux-3.2/include/linux/delay.h
===================================================================
--- linux-3.2.orig/include/linux/delay.h
+++ linux-3.2/include/linux/delay.h
@@ -52,4 +52,10 @@ static inline void ssleep(unsigned int s
msleep(seconds * 1000);
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define cpu_chill() msleep(1)
+#else
+# define cpu_chill() cpu_relax()
+#endif
+
#endif /* defined(_LINUX_DELAY_H) */
Index: linux-3.2/net/packet/af_packet.c
===================================================================
--- linux-3.2.orig/net/packet/af_packet.c
+++ linux-3.2/net/packet/af_packet.c
@@ -89,6 +89,7 @@
#include <linux/virtio_net.h>
#include <linux/errqueue.h>
#include <linux/net_tstamp.h>
+#include <linux/delay.h>
#ifdef CONFIG_INET
#include <net/inet_common.h>
@@ -673,7 +674,7 @@ static void prb_retire_rx_blk_timer_expi
if (BLOCK_NUM_PKTS(pbd)) {
while (atomic_read(&pkc->blk_fill_in_prog)) {
/* Waiting for skb_copy_bits to finish... */
- cpu_relax();
+ cpu_chill();
}
}
@@ -928,7 +929,7 @@ static void prb_retire_current_block(str
if (!(status & TP_STATUS_BLK_TMO)) {
while (atomic_read(&pkc->blk_fill_in_prog)) {
/* Waiting for skb_copy_bits to finish... */
- cpu_relax();
+ cpu_chill();
}
}
prb_close_block(pkc, pbd, po, status);
Index: linux-3.2/net/rds/ib_rdma.c
===================================================================
--- linux-3.2.orig/net/rds/ib_rdma.c
+++ linux-3.2/net/rds/ib_rdma.c
@@ -34,6 +34,7 @@
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/llist.h>
+#include <linux/delay.h>
#include "rds.h"
#include "ib.h"
@@ -286,7 +287,7 @@ static inline void wait_clean_list_grace
for_each_online_cpu(cpu) {
flag = &per_cpu(clean_list_grace, cpu);
while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
- cpu_relax();
+ cpu_chill();
}
}
--
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