[ANNOUNCE] 3.18.9-rt5

[ANNOUNCE] 3.18.9-rt5

[Sebastian Andrzej Siewior]

Dear RT folks!

I'm pleased to announce the v3.18.9-rt5 patch set.

Changes since v3.18.9-rt4

- fix non-rt builds. Reported by Neil Bradley, fixed by Steven Rostedt

- backport a patch from Lai Jiangshan which was suggested by Paul E.
  McKenney to avoid a RCU related race

- a bunch of stable marked patches for the radeon driver to avoid a
  freeze of the machine during heavy GPU usage. It was reported by
  Carsten Emde and he says that the machine does no longer lockup with
  them but X seems still to hang.

- a patch from Mike Galbraith to get FULL_NOHZ to work again. The patch
  ("rt-nohz_full-fix-nohz_full-for-PREEMPT_RT_FULL.patch") is included
  in the split out queue but is currently not enabled.

- lazy preempt on x86_64 is enabled again. It seems that it fixed
  itself.

Known issues:

      - bcache is disabled.

      - CPU hotplug works in general. Steven's test script however
        deadlocks usually on the second invocation.

      - xor / raid_pq
        I had max latency jumping up to 67563us on one CPU while the next
        lower max was 58us. I tracked it down to module's init code of
        xor and raid_pq. Both disable preemption while measuring the
        measuring the performance of the individual implementation.


The delta patch against 3.18.9-rt4 is appended below and can be found here: 

   https://www.kernel.org/pub/linux/kernel/projects/rt/3.18/incr/patch-3.18.9-rt4-rt5.patch.xz

The RT patch against 3.18.9 can be found here:

   https://www.kernel.org/pub/linux/kernel/projects/rt/3.18/patch-3.18.9-rt5.patch.xz

The split quilt queue is available at:

   https://www.kernel.org/pub/linux/kernel/projects/rt/3.18/patches-3.18.9-rt5.tar.xz

Sebastian

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5c4f25b843d9..25d692ddae4e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -21,7 +21,7 @@ config X86_64
 ### Arch settings
 config X86
 	def_bool y
-	select HAVE_PREEMPT_LAZY if X86_32
+	select HAVE_PREEMPT_LAZY
 	select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
 	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
 	select ARCH_HAS_FAST_MULTIPLIER
diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c
index 9328fb3dcfce..36a6bce74230 100644
--- a/drivers/gpu/drm/radeon/cik.c
+++ b/drivers/gpu/drm/radeon/cik.c
@@ -7295,7 +7295,6 @@ int cik_irq_set(struct radeon_device *rdev)
 	u32 hpd1, hpd2, hpd3, hpd4, hpd5, hpd6;
 	u32 grbm_int_cntl = 0;
 	u32 dma_cntl, dma_cntl1;
-	u32 thermal_int;
 
 	if (!rdev->irq.installed) {
 		WARN(1, "Can't enable IRQ/MSI because no handler is installed\n");
@@ -7332,13 +7331,6 @@ int cik_irq_set(struct radeon_device *rdev)
 	cp_m2p2 = RREG32(CP_ME2_PIPE2_INT_CNTL) & ~TIME_STAMP_INT_ENABLE;
 	cp_m2p3 = RREG32(CP_ME2_PIPE3_INT_CNTL) & ~TIME_STAMP_INT_ENABLE;
 
-	if (rdev->flags & RADEON_IS_IGP)
-		thermal_int = RREG32_SMC(CG_THERMAL_INT_CTRL) &
-			~(THERM_INTH_MASK | THERM_INTL_MASK);
-	else
-		thermal_int = RREG32_SMC(CG_THERMAL_INT) &
-			~(THERM_INT_MASK_HIGH | THERM_INT_MASK_LOW);
-
 	/* enable CP interrupts on all rings */
 	if (atomic_read(&rdev->irq.ring_int[RADEON_RING_TYPE_GFX_INDEX])) {
 		DRM_DEBUG("cik_irq_set: sw int gfx\n");
@@ -7496,14 +7488,6 @@ int cik_irq_set(struct radeon_device *rdev)
 		hpd6 |= DC_HPDx_INT_EN;
 	}
 
-	if (rdev->irq.dpm_thermal) {
-		DRM_DEBUG("dpm thermal\n");
-		if (rdev->flags & RADEON_IS_IGP)
-			thermal_int |= THERM_INTH_MASK | THERM_INTL_MASK;
-		else
-			thermal_int |= THERM_INT_MASK_HIGH | THERM_INT_MASK_LOW;
-	}
-
 	WREG32(CP_INT_CNTL_RING0, cp_int_cntl);
 
 	WREG32(SDMA0_CNTL + SDMA0_REGISTER_OFFSET, dma_cntl);
@@ -7557,10 +7541,8 @@ int cik_irq_set(struct radeon_device *rdev)
 	WREG32(DC_HPD5_INT_CONTROL, hpd5);
 	WREG32(DC_HPD6_INT_CONTROL, hpd6);
 
-	if (rdev->flags & RADEON_IS_IGP)
-		WREG32_SMC(CG_THERMAL_INT_CTRL, thermal_int);
-	else
-		WREG32_SMC(CG_THERMAL_INT, thermal_int);
+	/* posting read */
+	RREG32(SRBM_STATUS);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 85995b4e3338..c674f63d7f14 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -4589,6 +4589,9 @@ int evergreen_irq_set(struct radeon_device *rdev)
 	WREG32(AFMT_AUDIO_PACKET_CONTROL + EVERGREEN_CRTC4_REGISTER_OFFSET, afmt5);
 	WREG32(AFMT_AUDIO_PACKET_CONTROL + EVERGREEN_CRTC5_REGISTER_OFFSET, afmt6);
 
+	/* posting read */
+	RREG32(SRBM_STATUS);
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/radeon/kv_dpm.c b/drivers/gpu/drm/radeon/kv_dpm.c
index e3e9c10cfba9..85a109e1e56b 100644
--- a/drivers/gpu/drm/radeon/kv_dpm.c
+++ b/drivers/gpu/drm/radeon/kv_dpm.c
@@ -1169,6 +1169,19 @@ void kv_dpm_enable_bapm(struct radeon_device *rdev, bool enable)
 	}
 }
 
+static void kv_enable_thermal_int(struct radeon_device *rdev, bool enable)
+{
+	u32 thermal_int;
+
+	thermal_int = RREG32_SMC(CG_THERMAL_INT_CTRL);
+	if (enable)
+		thermal_int |= THERM_INTH_MASK | THERM_INTL_MASK;
+	else
+		thermal_int &= ~(THERM_INTH_MASK | THERM_INTL_MASK);
+	WREG32_SMC(CG_THERMAL_INT_CTRL, thermal_int);
+
+}
+
 int kv_dpm_enable(struct radeon_device *rdev)
 {
 	struct kv_power_info *pi = kv_get_pi(rdev);
@@ -1280,8 +1293,7 @@ int kv_dpm_late_enable(struct radeon_device *rdev)
 			DRM_ERROR("kv_set_thermal_temperature_range failed\n");
 			return ret;
 		}
-		rdev->irq.dpm_thermal = true;
-		radeon_irq_set(rdev);
+		kv_enable_thermal_int(rdev, true);
 	}
 
 	/* powerdown unused blocks for now */
@@ -1312,6 +1324,7 @@ void kv_dpm_disable(struct radeon_device *rdev)
 	kv_stop_dpm(rdev);
 	kv_enable_ulv(rdev, false);
 	kv_reset_am(rdev);
+	kv_enable_thermal_int(rdev, false);
 
 	kv_update_current_ps(rdev, rdev->pm.dpm.boot_ps);
 }
diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 56b02927cd3d..ee0868dec2f4 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -3787,6 +3787,9 @@ int r600_irq_set(struct radeon_device *rdev)
 		WREG32(RV770_CG_THERMAL_INT, thermal_int);
 	}
 
+	/* posting read */
+	RREG32(R_000E50_SRBM_STATUS);
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index 995167025282..8569afaba688 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -1029,37 +1029,59 @@ static inline bool radeon_test_signaled(struct radeon_fence *fence)
 	return test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->base.flags);
 }
 
+struct radeon_wait_cb {
+	struct fence_cb base;
+	struct task_struct *task;
+};
+
+static void
+radeon_fence_wait_cb(struct fence *fence, struct fence_cb *cb)
+{
+	struct radeon_wait_cb *wait =
+		container_of(cb, struct radeon_wait_cb, base);
+
+	wake_up_process(wait->task);
+}
+
 static signed long radeon_fence_default_wait(struct fence *f, bool intr,
 					     signed long t)
 {
 	struct radeon_fence *fence = to_radeon_fence(f);
 	struct radeon_device *rdev = fence->rdev;
-	bool signaled;
+	struct radeon_wait_cb cb;
 
-	fence_enable_sw_signaling(&fence->base);
+	cb.task = current;
 
-	/*
-	 * This function has to return -EDEADLK, but cannot hold
-	 * exclusive_lock during the wait because some callers
-	 * may already hold it. This means checking needs_reset without
-	 * lock, and not fiddling with any gpu internals.
-	 *
-	 * The callback installed with fence_enable_sw_signaling will
-	 * run before our wait_event_*timeout call, so we will see
-	 * both the signaled fence and the changes to needs_reset.
-	 */
+	if (fence_add_callback(f, &cb.base, radeon_fence_wait_cb))
+		return t;
+
+	while (t > 0) {
+		if (intr)
+			set_current_state(TASK_INTERRUPTIBLE);
+		else
+			set_current_state(TASK_UNINTERRUPTIBLE);
+
+		/*
+		 * radeon_test_signaled must be called after
+		 * set_current_state to prevent a race with wake_up_process
+		 */
+		if (radeon_test_signaled(fence))
+			break;
+
+		if (rdev->needs_reset) {
+			t = -EDEADLK;
+			break;
+		}
+
+		t = schedule_timeout(t);
+
+		if (t > 0 && intr && signal_pending(current))
+			t = -ERESTARTSYS;
+	}
+
+	__set_current_state(TASK_RUNNING);
+	fence_remove_callback(f, &cb.base);
 
-	if (intr)
-		t = wait_event_interruptible_timeout(rdev->fence_queue,
-			((signaled = radeon_test_signaled(fence)) ||
-			 rdev->needs_reset), t);
-	else
-		t = wait_event_timeout(rdev->fence_queue,
-			((signaled = radeon_test_signaled(fence)) ||
-			 rdev->needs_reset), t);
-
-	if (t > 0 && !signaled)
-		return -EDEADLK;
 	return t;
 }
 
diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index 74bce91aecc1..039660662ee8 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -693,6 +693,10 @@ int rs600_irq_set(struct radeon_device *rdev)
 	WREG32(R_007D18_DC_HOT_PLUG_DETECT2_INT_CONTROL, hpd2);
 	if (ASIC_IS_DCE2(rdev))
 		WREG32(R_007408_HDMI0_AUDIO_PACKET_CONTROL, hdmi0);
+
+	/* posting read */
+	RREG32(R_000040_GEN_INT_CNTL);
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 7d5083dc4acb..35ce05c78c4d 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -6192,6 +6192,9 @@ int si_irq_set(struct radeon_device *rdev)
 
 	WREG32(CG_THERMAL_INT, thermal_int);
 
+	/* posting read */
+	RREG32(SRBM_STATUS);
+
 	return 0;
 }
 
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 0c6491228b17..4b53470bf97b 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -147,7 +147,9 @@ bool irq_work_needs_cpu(void)
 
 	if (llist_empty(raised))
 		if (llist_empty(lazy))
+#ifdef CONFIG_PREEMPT_RT_FULL
 			if (llist_empty(this_cpu_ptr(&hirq_work_list)))
+#endif
 				return false;
 
 	/* All work should have been flushed before going offline */
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 4245a2dc1911..e8508b4febc5 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -173,11 +173,6 @@ struct rcu_node {
 				/*  queued on this rcu_node structure that */
 				/*  are blocking the current grace period, */
 				/*  there can be no such task. */
-	struct completion boost_completion;
-				/* Used to ensure that the rt_mutex used */
-				/*  to carry out the boosting is fully */
-				/*  released with no future boostee accesses */
-				/*  before that rt_mutex is re-initialized. */
 	struct rt_mutex boost_mtx;
 				/* Used only for the priority-boosting */
 				/*  side effect, not as a lock. */
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index e19cfc0a881a..ecd967ecc7ce 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -392,10 +392,8 @@ void rcu_read_unlock_special(struct task_struct *t)
 
 #ifdef CONFIG_RCU_BOOST
 		/* Unboost if we were boosted. */
-		if (drop_boost_mutex) {
+		if (drop_boost_mutex)
 			rt_mutex_unlock(&rnp->boost_mtx);
-			complete(&rnp->boost_completion);
-		}
 #endif /* #ifdef CONFIG_RCU_BOOST */
 
 		/*
@@ -1163,15 +1161,11 @@ static int rcu_boost(struct rcu_node *rnp)
 	 */
 	t = container_of(tb, struct task_struct, rcu_node_entry);
 	rt_mutex_init_proxy_locked(&rnp->boost_mtx, t);
-	init_completion(&rnp->boost_completion);
 	raw_spin_unlock_irqrestore(&rnp->lock, flags);
 	/* Lock only for side effect: boosts task t's priority. */
 	rt_mutex_lock(&rnp->boost_mtx);
 	rt_mutex_unlock(&rnp->boost_mtx);  /* Then keep lockdep happy. */
 
-	/* Wait for boostee to be done w/boost_mtx before reinitializing. */
-	wait_for_completion(&rnp->boost_completion);

Re: [ANNOUNCE] 3.18.9-rt5

[Ralf Mardorf]

Hi,

if the powernow-k8 module is loaded my Athlon BE-2350 dual-core machine
hangs at startup. After building the kernel with
"CONFIG_X86_POWERNOW_K8 is not set" startup finishes.

For older linux-rt versions I could unbind 2 USB ports sharing an IRQ
with my sound card, by one and the same script, now it doesn't work
anymore.

The status of rtirq reports one IRQ with a "cryptic" name.
I'm still using rtirq 20130402, not the current version 20150216, but the
version of rtirq seems not to be the culprit.

[1] rtirq status for 3.18.9-rt5
[2] rtirq status for an older kernel

Regards,
Ralf


[1]

[rocketmouse@archlinux ~]$ grep 0000 /usr/local/sbin/tuning
echo -n "0000:00:13.2" > /sys/bus/pci/drivers/ohci_hcd/unbind
echo -n "0000:00:13.4" > /sys/bus/pci/drivers/ohci_hcd/unbind

[rocketmouse@archlinux ~]$ sudo tuning
[sudo] password for rocketmouse: 
/usr/local/sbin/tuning: line 28: /sys/bus/pci/drivers/ohci_hcd/unbind: No such file or directory
/usr/local/sbin/tuning: line 29: /sys/bus/pci/drivers/ohci_hcd/unbind: No such file or directory

########################################################################

# service rtirq status           

  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND	
   46 FF      90   - 130  0.0 S    irq/8-rtc0	
  224 FF      85   - 125  0.0 S    irq/18-snd_hdsp	
  220 FF      80   - 120  0.0 S    irq/20-snd_ice1	
  221 FF      79   - 119  0.0 S    irq/21-snd_ice1	
   78 FF      75   - 115  0.0 S    irq/1-i8042	
   35 FF      50   -  90  0.0 S    irq/9-acpi	
   64 FF      50   -  90  0.0 S    irq/26-radeon	
   84 FF      50   -  90  0.0 S    irq/14-pata_ati	
   85 FF      50   -  90  0.0 S    irq/15-pata_ati	
   92 FF      50   -  90  0.0 S    irq/22-0000:00:	
  102 FF      50   -  90  0.0 S    irq/19-ehci_hcd	
  106 FF      50   -  90  0.0 S    irq/16-ohci_hcd	
  107 FF      50   -  90  0.0 S    irq/17-ohci_hcd	
  109 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  110 FF      50   -  90  0.0 S    irq/17-ohci_hcd	
  112 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  205 FF      50   -  90  0.0 S    irq/7-parport0	
  399 FF      50   -  90  0.0 S    irq/27-enp3s0	
    3 FF       1   -  41  0.2 S    ksoftirqd/0	
   19 FF       1   -  41  0.2 S    ksoftirqd/1	

# grep 18: /proc/interrupts
 18:          0          2   IO-APIC  18-fasteoi   ohci_hcd:usb4, ohci_hcd:usb6, snd_hdspm

Tue Mar 17 23:46:10 CET 2015 - 3.18.9-rt5-2-rt - Arch Linux \r (\l)





[2]

[rocketmouse@archlinux ~]$ sudo tuning
[sudo] password for rocketmouse: 

########################################################################

# service rtirq status           

  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND	
   43 FF      90   - 130  0.0 S    irq/8-rtc0	
  197 FF      85   - 125  0.0 S    irq/18-snd_hdsp	
  198 FF      80   - 120  0.0 S    irq/20-snd_ice1	
  199 FF      79   - 119  0.0 S    irq/21-snd_ice1	
   41 FF      75   - 115  0.0 S    irq/1-i8042	
   30 FF      50   -  90  0.0 S    irq/9-acpi	
   61 FF      50   -  90  0.0 S    irq/42-radeon	
   78 FF      50   -  90  0.5 S    irq/22-ahci	
   87 FF      50   -  90  0.0 S    irq/14-pata_ati	
   89 FF      50   -  90  0.0 S    irq/15-pata_ati	
   94 FF      50   -  90  0.0 S    irq/19-ehci_hcd	
   98 FF      50   -  90  0.0 S    irq/16-ohci_hcd	
   99 FF      50   -  90  0.1 S    irq/17-ohci_hcd	
  101 FF      50   -  90  0.0 S    irq/17-ohci_hcd	
  188 FF      50   -  90  0.0 S    irq/7-parport0	
  366 FF      50   -  90  0.0 S    irq/43-enp3s0	
    3 FF       1   -  41  0.5 S    ksoftirqd/0	
   19 FF       1   -  41  0.5 S    ksoftirqd/1	

# grep 18: /proc/interrupts
 18:          0          4   IO-APIC-fasteoi   snd_hdspm

Tue Mar 17 23:59:35 CET 2015 - 3.10.61-rt65-1-rt-lts - Arch Linux \r (\l)

Re: [ANNOUNCE] 3.18.9-rt5

[Joakim Hernberg]

On Wed, 18 Mar 2015 10:08:17 +0100
Ralf Mardorf <ralf.mardorf@alice-dsl.net> wrote:

> The status of rtirq reports one IRQ with a "cryptic" name.
> I'm still using rtirq 20130402, not the current version 20150216, but
> the version of rtirq seems not to be the culprit.

This seems to be an upstream change.  I see the same for the AHCI
controllers on the 2 systems I've checked so far.  The same thing
happens on the archlinux distro kernel (3.18.6). 

Suppose the change has been done to be able to distinguish one
controller from another on systems having more than one AHCI
controller.  In fact I would personally be happy if some way was found
to do the same for all the USB hubs.

-- 

   Joakim

Re: [ANNOUNCE] 3.18.9-rt5

[Mike Galbraith]

On Mon, 2015-03-16 at 22:01 +0100, Sebastian Andrzej Siewior wrote:
> Dear RT folks!

> - lazy preempt on x86_64 is enabled again. It seems that it fixed
>   itself.

009f60e2 sched: stop the unbound recursion in preempt_schedule_context()