Dear RT folks!
I'm pleased to announce the v5.2.9-rt3 patch set.
Changes since v5.2.9-rt2:
- The exynos5 i2c controller disabled IRQ threading as reported by
Benjamin Rouxel. The hix5hd2 i2c controller did the same.
- A timer related to the deadline scheduler now fires in hard-irq
context. Patch by Juri Lelli.
- A lock used the x86's thermal exception uses a raw_spinlock_t. Patch
by Clark Williams.
- The DMA-reservation code is using now a sequence lock instead a
sequence counter. Yann Collette reported warnings from that area
with an AMD GPU.
- Two kvm related timer on arm64 expire now hard-irq context. Reported
by Julien Grall, patched by Thomas Gleixner.
- Lazy preemption was broken in a case on arm64, reported by Paul
Thomas. While investigating another lazy-preempt bug was fixed on
arm64 and x86.
Known issues
- rcutorture is currently broken on -RT. Reported by Juri Lelli.
The delta patch against v5.2.9-rt2 is appended below and can be found here:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.2/incr/patch-5.2.9-rt2-rt3.patch.xz
You can get this release via the git tree at:
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
v5.2.9-rt3
The RT patch against v5.2.9 can be found here:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.2/older/patch-5.2.9-rt3.patch.xz
The split quilt queue is available at:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.2/older/patches-5.2.9-rt3.tar.xz
Sebastian
diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h
index 3bfad251203b5..ca1c6fe8dd347 100644
--- a/arch/arm64/include/asm/preempt.h
+++ b/arch/arm64/include/asm/preempt.h
@@ -73,6 +73,8 @@ static inline bool __preempt_count_dec_and_test(void)
if (!pc || !READ_ONCE(ti->preempt_count))
return true;
#ifdef CONFIG_PREEMPT_LAZY
+ if ((pc & ~PREEMPT_NEED_RESCHED))
+ return false;
if (current_thread_info()->preempt_lazy_count)
return false;
return test_thread_flag(TIF_NEED_RESCHED_LAZY);
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index aa16cb43a779e..5d651c560bba6 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -680,7 +680,8 @@ alternative_if ARM64_HAS_IRQ_PRIO_MASKING
orr x24, x24, x0
alternative_else_nop_endif
- cbnz x24, 2f // preempt count != 0
+ cbz x24, 1f // (need_resched +
count) == 0
+ cbnz w24, 2f // count != 0
ldr w24, [tsk, #TSK_TI_PREEMPT_LAZY] // get preempt lazy
count
cbnz w24, 2f // preempt lazy count
!= 0
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index f8e42abd874a4..9496299d23fc3 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -99,6 +99,8 @@ static __always_inline bool __preempt_count_dec_and_test(void)
if (____preempt_count_dec_and_test())
return true;
#ifdef CONFIG_PREEMPT_LAZY
+ if (preempt_count())
+ return false;
if (current_thread_info()->preempt_lazy_count)
return false;
return test_thread_flag(TIF_NEED_RESCHED_LAZY);
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index a6fee5a6e9fb2..27fffd65abe6b 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -168,7 +168,7 @@ static __poll_t dma_buf_poll(struct file *file, poll_table
*poll)
return 0;
retry:
- seq = read_seqcount_begin(&resv->seq);
+ seq = read_seqbegin(&resv->seq);
rcu_read_lock();
fobj = rcu_dereference(resv->fence);
@@ -177,7 +177,7 @@ static __poll_t dma_buf_poll(struct file *file, poll_table
*poll)
else
shared_count = 0;
fence_excl = rcu_dereference(resv->fence_excl);
- if (read_seqcount_retry(&resv->seq, seq)) {
+ if (read_seqretry(&resv->seq, seq)) {
rcu_read_unlock();
goto retry;
}
@@ -1034,12 +1034,12 @@ static int dma_buf_debug_show(struct seq_file *s, void
*unused)
robj = buf_obj->resv;
while (true) {
- seq = read_seqcount_begin(&robj->seq);
+ seq = read_seqbegin(&robj->seq);
rcu_read_lock();
fobj = rcu_dereference(robj->fence);
shared_count = fobj ? fobj->shared_count : 0;
fence = rcu_dereference(robj->fence_excl);
- if (!read_seqcount_retry(&robj->seq, seq))
+ if (!read_seqretry(&robj->seq, seq))
break;
rcu_read_unlock();
}
diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index 4447e13d1e891..030c45ad3e56a 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -110,15 +110,13 @@ int reservation_object_reserve_shared(struct
reservation_object *obj,
new->shared_count = j;
new->shared_max = max;
- preempt_disable();
- write_seqcount_begin(&obj->seq);
+ write_seqlock(&obj->seq);
/*
* RCU_INIT_POINTER can be used here,
* seqcount provides the necessary barriers
*/
RCU_INIT_POINTER(obj->fence, new);
- write_seqcount_end(&obj->seq);
- preempt_enable();
+ write_sequnlock(&obj->seq);
if (!old)
return 0;
@@ -158,8 +156,7 @@ void reservation_object_add_shared_fence(struct
reservation_object *obj,
fobj = reservation_object_get_list(obj);
count = fobj->shared_count;
- preempt_disable();
- write_seqcount_begin(&obj->seq);
+ write_seqlock(&obj->seq);
for (i = 0; i < count; ++i) {
struct dma_fence *old_fence;
@@ -181,8 +178,7 @@ void reservation_object_add_shared_fence(struct
reservation_object *obj,
/* pointer update must be visible before we extend the shared_count */
smp_store_mb(fobj->shared_count, count);
- write_seqcount_end(&obj->seq);
- preempt_enable();
+ write_sequnlock(&obj->seq);
}
EXPORT_SYMBOL(reservation_object_add_shared_fence);
@@ -209,14 +205,11 @@ void reservation_object_add_excl_fence(struct
reservation_object *obj,
if (fence)
dma_fence_get(fence);
- preempt_disable();
- write_seqcount_begin(&obj->seq);
- /* write_seqcount_begin provides the necessary memory barrier */
+ write_seqlock(&obj->seq);
RCU_INIT_POINTER(obj->fence_excl, fence);
if (old)
old->shared_count = 0;
- write_seqcount_end(&obj->seq);
- preempt_enable();
+ write_sequnlock(&obj->seq);
/* inplace update, no shared fences */
while (i--)
@@ -298,13 +291,10 @@ int reservation_object_copy_fences(struct
reservation_object *dst,
src_list = reservation_object_get_list(dst);
old = reservation_object_get_excl(dst);
- preempt_disable();
- write_seqcount_begin(&dst->seq);
- /* write_seqcount_begin provides the necessary memory barrier */
+ write_seqlock(&dst->seq);
RCU_INIT_POINTER(dst->fence_excl, new);
RCU_INIT_POINTER(dst->fence, dst_list);
- write_seqcount_end(&dst->seq);
- preempt_enable();
+ write_sequnlock(&dst->seq);
if (src_list)
kfree_rcu(src_list, rcu);
@@ -345,7 +335,7 @@ int reservation_object_get_fences_rcu(struct
reservation_object *obj,
shared_count = i = 0;
rcu_read_lock();
- seq = read_seqcount_begin(&obj->seq);
+ seq = read_seqbegin(&obj->seq);
fence_excl = rcu_dereference(obj->fence_excl);
if (fence_excl && !dma_fence_get_rcu(fence_excl))
@@ -394,7 +384,7 @@ int reservation_object_get_fences_rcu(struct
reservation_object *obj,
}
}
- if (i != shared_count || read_seqcount_retry(&obj->seq, seq)) {
+ if (i != shared_count || read_seqretry(&obj->seq, seq)) {
while (i--)
dma_fence_put(shared[i]);
dma_fence_put(fence_excl);
@@ -443,7 +433,7 @@ long reservation_object_wait_timeout_rcu(struct
reservation_object *obj,
retry:
shared_count = 0;
- seq = read_seqcount_begin(&obj->seq);
+ seq = read_seqbegin(&obj->seq);
rcu_read_lock();
i = -1;
@@ -490,7 +480,7 @@ long reservation_object_wait_timeout_rcu(struct
reservation_object *obj,
rcu_read_unlock();
if (fence) {
- if (read_seqcount_retry(&obj->seq, seq)) {
+ if (read_seqretry(&obj->seq, seq)) {
dma_fence_put(fence);
goto retry;
}
@@ -546,7 +536,7 @@ bool reservation_object_test_signaled_rcu(struct
reservation_object *obj,
retry:
ret = true;
shared_count = 0;
- seq = read_seqcount_begin(&obj->seq);
+ seq = read_seqbegin(&obj->seq);
if (test_all) {
unsigned i;
@@ -567,7 +557,7 @@ bool reservation_object_test_signaled_rcu(struct
reservation_object *obj,
break;
}
- if (read_seqcount_retry(&obj->seq, seq))
+ if (read_seqretry(&obj->seq, seq))
goto retry;
}
@@ -580,7 +570,7 @@ bool reservation_object_test_signaled_rcu(struct
reservation_object *obj,
if (ret < 0)
goto retry;
- if (read_seqcount_retry(&obj->seq, seq))
+ if (read_seqretry(&obj->seq, seq))
goto retry;
}
}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 4b192e0ce92f4..be625817e5d95 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -250,11 +250,9 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct
amdgpu_bo *bo,
new->shared_count = k;
/* Install the new fence list, seqcount provides the barriers */
- preempt_disable();
- write_seqcount_begin(&resv->seq);
+ write_seqlock(&resv->seq);
RCU_INIT_POINTER(resv->fence, new);
- write_seqcount_end(&resv->seq);
- preempt_enable();
+ write_sequnlock(&resv->seq);
/* Drop the references to the removed fences or move them to ef_list */
for (i = j, k = 0; i < old->shared_count; ++i) {
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ad01c92aaf748..2910a133077a3 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -449,7 +449,7 @@ i915_gem_object_wait_reservation(struct reservation_object
*resv,
unsigned int flags,
long timeout)
{
- unsigned int seq = __read_seqcount_begin(&resv->seq);
+ unsigned int seq = read_seqbegin(&resv->seq);
struct dma_fence *excl;
bool prune_fences = false;
@@ -500,9 +500,9 @@ i915_gem_object_wait_reservation(struct reservation_object
*resv,
* signaled and that the reservation object has not been changed (i.e.
* no new fences have been added).
*/
- if (prune_fences && !__read_seqcount_retry(&resv->seq, seq)) {
+ if (prune_fences && !read_seqretry(&resv->seq, seq)) {
if (reservation_object_trylock(resv)) {
- if (!__read_seqcount_retry(&resv->seq, seq))
+ if (!read_seqretry(&resv->seq, seq))
reservation_object_add_excl_fence(resv, NULL);
reservation_object_unlock(resv);
}
@@ -3943,7 +3943,7 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
*
*/
retry:
- seq = raw_read_seqcount(&obj->resv->seq);
+ seq = read_seqbegin(&obj->resv->seq);
/* Translate the exclusive fence to the READ *and* WRITE engine */
args->busy = busy_check_writer(rcu_dereference(obj->resv->fence_excl));
@@ -3961,7 +3961,7 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
}
}
- if (args->busy && read_seqcount_retry(&obj->resv->seq, seq))
+ if (args->busy && read_seqretry(&obj->resv->seq, seq))
goto retry;
err = 0;
diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index e4e7932f78000..e7514c16b756c 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -791,9 +791,7 @@ static int exynos5_i2c_probe(struct platform_device *pdev)
}
ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq,
- IRQF_NO_SUSPEND | IRQF_ONESHOT,
- dev_name(&pdev->dev), i2c);
-
+ IRQF_NO_SUSPEND, dev_name(&pdev->dev), i2c);
if (ret != 0) {
dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", i2c->irq);
goto err_clk;
diff --git a/drivers/i2c/busses/i2c-hix5hd2.c b/drivers/i2c/busses/i2c-hix5hd2.c
index 4df1434b3597d..8497c7a95dd44 100644
--- a/drivers/i2c/busses/i2c-hix5hd2.c
+++ b/drivers/i2c/busses/i2c-hix5hd2.c
@@ -445,8 +445,7 @@ static int hix5hd2_i2c_probe(struct platform_device *pdev)
hix5hd2_i2c_init(priv);
ret = devm_request_irq(&pdev->dev, irq, hix5hd2_i2c_irq,
- IRQF_NO_SUSPEND | IRQF_ONESHOT,
- dev_name(&pdev->dev), priv);
+ IRQF_NO_SUSPEND, dev_name(&pdev->dev), priv);
if (ret != 0) {
dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", irq);
goto err_clk;
diff --git a/drivers/thermal/intel/x86_pkg_temp_thermal.c
b/drivers/thermal/intel/x86_pkg_temp_thermal.c
index 319b771261686..92ceed3de6f39 100644
--- a/drivers/thermal/intel/x86_pkg_temp_thermal.c
+++ b/drivers/thermal/intel/x86_pkg_temp_thermal.c
@@ -63,7 +63,7 @@ static int max_packages __read_mostly;
/* Array of package pointers */
static struct pkg_device **packages;
/* Serializes interrupt notification, work and hotplug */
-static DEFINE_SPINLOCK(pkg_temp_lock);
+static DEFINE_RAW_SPINLOCK(pkg_temp_lock);
/* Protects zone operation in the work function against hotplug removal */
static DEFINE_MUTEX(thermal_zone_mutex);
@@ -279,12 +279,12 @@ static void pkg_temp_thermal_threshold_work_fn(struct
work_struct *work)
u64 msr_val, wr_val;
mutex_lock(&thermal_zone_mutex);
- spin_lock_irq(&pkg_temp_lock);
+ raw_spin_lock_irq(&pkg_temp_lock);
++pkg_work_cnt;
pkgdev = pkg_temp_thermal_get_dev(cpu);
if (!pkgdev) {
- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);
mutex_unlock(&thermal_zone_mutex);
return;
}
@@ -298,7 +298,7 @@ static void pkg_temp_thermal_threshold_work_fn(struct
work_struct *work)
}
enable_pkg_thres_interrupt();
- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);
/*
* If tzone is not NULL, then thermal_zone_mutex will prevent the
@@ -323,7 +323,7 @@ static int pkg_thermal_notify(u64 msr_val)
struct pkg_device *pkgdev;
unsigned long flags;
- spin_lock_irqsave(&pkg_temp_lock, flags);
+ raw_spin_lock_irqsave(&pkg_temp_lock, flags);
++pkg_interrupt_cnt;
disable_pkg_thres_interrupt();
@@ -335,7 +335,7 @@ static int pkg_thermal_notify(u64 msr_val)
pkg_thermal_schedule_work(pkgdev->cpu, &pkgdev->work);
}
- spin_unlock_irqrestore(&pkg_temp_lock, flags);
+ raw_spin_unlock_irqrestore(&pkg_temp_lock, flags);
return 0;
}
@@ -381,9 +381,9 @@ static int pkg_temp_thermal_device_add(unsigned int cpu)
pkgdev->msr_pkg_therm_high);
cpumask_set_cpu(cpu, &pkgdev->cpumask);
- spin_lock_irq(&pkg_temp_lock);
+ raw_spin_lock_irq(&pkg_temp_lock);
packages[pkgid] = pkgdev;
- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);
return 0;
}
@@ -420,7 +420,7 @@ static int pkg_thermal_cpu_offline(unsigned int cpu)
}
/* Protect against work and interrupts */
- spin_lock_irq(&pkg_temp_lock);
+ raw_spin_lock_irq(&pkg_temp_lock);
/*
* Check whether this cpu was the current target and store the new
@@ -452,9 +452,9 @@ static int pkg_thermal_cpu_offline(unsigned int cpu)
* To cancel the work we need to drop the lock, otherwise
* we might deadlock if the work needs to be flushed.
*/
- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);
cancel_delayed_work_sync(&pkgdev->work);
- spin_lock_irq(&pkg_temp_lock);
+ raw_spin_lock_irq(&pkg_temp_lock);
/*
* If this is not the last cpu in the package and the work
* did not run after we dropped the lock above, then we
@@ -465,7 +465,7 @@ static int pkg_thermal_cpu_offline(unsigned int cpu)
pkg_thermal_schedule_work(target, &pkgdev->work);
}
- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);
/* Final cleanup if this is the last cpu */
if (lastcpu)
diff --git a/include/linux/reservation.h b/include/linux/reservation.h
index ee750765cc941..11cc05f489365 100644
--- a/include/linux/reservation.h
+++ b/include/linux/reservation.h
@@ -71,7 +71,7 @@ struct reservation_object_list {
*/
struct reservation_object {
struct ww_mutex lock;
- seqcount_t seq;
+ seqlock_t seq;
struct dma_fence __rcu *fence_excl;
struct reservation_object_list __rcu *fence;
@@ -90,7 +90,7 @@ reservation_object_init(struct reservation_object *obj)
{
ww_mutex_init(&obj->lock, &reservation_ww_class);
- __seqcount_init(&obj->seq, reservation_seqcount_string,
&reservation_seqcount_class);
+ seqlock_init(&obj->seq);
RCU_INIT_POINTER(obj->fence, NULL);
RCU_INIT_POINTER(obj->fence_excl, NULL);
}
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index c18be51f76088..1758f2a2d775a 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -287,7 +287,7 @@ static void task_non_contending(struct task_struct *p)
dl_se->dl_non_contending = 1;
get_task_struct(p);
- hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL);
+ hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL_HARD);
}
static void task_contending(struct sched_dl_entity *dl_se, int flags)
@@ -1292,7 +1292,7 @@ void init_dl_inactive_task_timer(struct sched_dl_entity
*dl_se)
{
struct hrtimer *timer = &dl_se->inactive_timer;
- hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
timer->function = inactive_task_timer;
}
diff --git a/localversion-rt b/localversion-rt
index c3054d08a1129..1445cd65885cd 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt2
+-rt3
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 1be486d5d7cb4..0bfa7c5b5c890 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -80,7 +80,7 @@ static inline bool userspace_irqchip(struct kvm *kvm)
static void soft_timer_start(struct hrtimer *hrt, u64 ns)
{
hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns),
- HRTIMER_MODE_ABS);
+ HRTIMER_MODE_ABS_HARD);
}
static void soft_timer_cancel(struct hrtimer *hrt)
@@ -697,11 +697,11 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
update_vtimer_cntvoff(vcpu, kvm_phys_timer_read());
ptimer->cntvoff = 0;
- hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init(&timer->bg_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
timer->bg_timer.function = kvm_bg_timer_expire;
- hrtimer_init(&vtimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
- hrtimer_init(&ptimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init(&vtimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
+ hrtimer_init(&ptimer->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
vtimer->hrtimer.function = kvm_hrtimer_expire;
ptimer->hrtimer.function = kvm_hrtimer_expire;
