* [PATCH 0/2] lockdep cross-release fallout from -rc1
@ 2017-11-29 15:41 Daniel Vetter
2017-11-29 15:41 ` [PATCH 1/2] lockdep: finer-grained completion key for kthread Daniel Vetter
2017-11-29 15:41 ` [PATCH 2/2] lockdep: Up MAX_LOCKDEP_CHAINS Daniel Vetter
0 siblings, 2 replies; 6+ messages in thread
From: Daniel Vetter @ 2017-11-29 15:41 UTC (permalink / raw)
To: LKML, Peter Zijlstra, Ingo Molnar, Thomas Gleixner
Cc: Intel Graphics Development, Tejun Heo, Kees Cook, Daniel Vetter
Hi all,
-rc1 set our CI on fire with a pile of issues that cross-release
highlights. The two patches in this series get things back into working
order on our side, so we pulled them into our local branches to unblock CI
and drm/i915.
But they're ofc far from polished, so pls look at this more as a bug
report than bugfix submission :-)
Cheers, Daniel
Daniel Vetter (2):
lockdep: finer-grained completion key for kthread
lockdep: Up MAX_LOCKDEP_CHAINS
include/linux/kthread.h | 48 ++++++++++++++++++++++----
kernel/kthread.c | 70 ++++++++++++++++++++++++++------------
kernel/locking/lockdep_internals.h | 2 +-
3 files changed, 91 insertions(+), 29 deletions(-)
--
2.15.0
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/2] lockdep: finer-grained completion key for kthread
2017-11-29 15:41 [PATCH 0/2] lockdep cross-release fallout from -rc1 Daniel Vetter
@ 2017-11-29 15:41 ` Daniel Vetter
2017-12-04 8:16 ` Daniel Vetter
2017-11-29 15:41 ` [PATCH 2/2] lockdep: Up MAX_LOCKDEP_CHAINS Daniel Vetter
1 sibling, 1 reply; 6+ messages in thread
From: Daniel Vetter @ 2017-11-29 15:41 UTC (permalink / raw)
To: LKML, Peter Zijlstra, Ingo Molnar, Thomas Gleixner
Cc: Intel Graphics Development, Tejun Heo, Kees Cook, Daniel Vetter,
Tvrtko Ursulin, Marta Lofstedt, Daniel Vetter
Ideally we'd create the key through a macro at the real callers and
pass it all the way down. This would give us better coverage for cases
where a bunch of kthreads are created for the same thing.
But this gets the job done meanwhile and unblocks our CI. Refining
later on is always possible.
v2:
- make it compile
- use the right map (Tvrtko)
v3:
lockdep insist on a static key, so the cheap way didn't work. Wire
2 keys through all the callers.
I didn't extend this up to alloc_workqueue because the
lockdep_invariant_state() call should separate the work functions from
the workqueue kthread logic and prevent cross-release state from
leaking between unrelated work queues that happen to reuse the same
kthreads.
v4: CI found more compile fail :-/
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Marta Lofstedt <marta.lofstedt@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=103950
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
---
include/linux/kthread.h | 48 ++++++++++++++++++++++++++++-----
kernel/kthread.c | 70 ++++++++++++++++++++++++++++++++++---------------
2 files changed, 90 insertions(+), 28 deletions(-)
diff --git a/include/linux/kthread.h b/include/linux/kthread.h
index c1961761311d..7a9463f0be5c 100644
--- a/include/linux/kthread.h
+++ b/include/linux/kthread.h
@@ -6,10 +6,12 @@
#include <linux/sched.h>
#include <linux/cgroup.h>
-__printf(4, 5)
-struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
+__printf(6, 7)
+struct task_struct *_kthread_create_on_node(int (*threadfn)(void *data),
void *data,
int node,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
const char namefmt[], ...);
/**
@@ -25,12 +27,27 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
*/
#define kthread_create(threadfn, data, namefmt, arg...) \
kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
+#define kthread_create_on_node(threadfn, data, node, namefmt, arg...) \
+({ \
+ static struct lock_class_key __exited_key, __parked_key; \
+ _kthread_create_on_node(threadfn, data, node, &__exited_key, \
+ &__parked_key, namefmt, ##arg); \
+})
-struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
+struct task_struct *_kthread_create_on_cpu(int (*threadfn)(void *data),
void *data,
unsigned int cpu,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
const char *namefmt);
+#define kthread_create_on_cpu(threadfn, data, cpu, namefmt) \
+({ \
+ static struct lock_class_key __exited_key, __parked_key; \
+ _kthread_create_on_cpu(threadfn, data, cpu, &__exited_key,\
+ &__parked_key, namefmt); \
+})
+
/**
* kthread_run - create and wake a thread.
@@ -171,13 +188,30 @@ extern void __kthread_init_worker(struct kthread_worker *worker,
int kthread_worker_fn(void *worker_ptr);
-__printf(2, 3)
+__printf(4, 5)
struct kthread_worker *
-kthread_create_worker(unsigned int flags, const char namefmt[], ...);
+_kthread_create_worker(unsigned int flags,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
+ const char namefmt[], ...);
+#define kthread_create_worker(flags, namefmt...) \
+({ \
+ static struct lock_class_key __exited_key, __parked_key; \
+ _kthread_create_worker(flags, &__exited_key, &__parked_key, \
+ ##namefmt); \
+})
-__printf(3, 4) struct kthread_worker *
-kthread_create_worker_on_cpu(int cpu, unsigned int flags,
+__printf(5, 6) struct kthread_worker *
+_kthread_create_worker_on_cpu(int cpu, unsigned int flags,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
const char namefmt[], ...);
+#define kthread_create_worker_on_cpu(cpu, flags, namefmt...) \
+({ \
+ static struct lock_class_key __exited_key, __parked_key; \
+ _kthread_create_worker_on_cpu(cpu, flags, &__exited_key, &__parked_key,\
+ ##namefmt); \
+})
bool kthread_queue_work(struct kthread_worker *worker,
struct kthread_work *work);
diff --git a/kernel/kthread.c b/kernel/kthread.c
index cd50e99202b0..9022806818fc 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -32,6 +32,7 @@ struct kthread_create_info
int (*threadfn)(void *data);
void *data;
int node;
+ struct lock_class_key *exited_key, *parked_key;
/* Result passed back to kthread_create() from kthreadd. */
struct task_struct *result;
@@ -221,8 +222,17 @@ static int kthread(void *_create)
}
self->data = data;
- init_completion(&self->exited);
- init_completion(&self->parked);
+ /* these two completions are shared with all kthread, which is bonghist
+ * imo */
+ lockdep_init_map_crosslock(&self->exited.map.map,
+ "(kthread completion)->exited",
+ create->exited_key, 0);
+ init_completion_map(&self->exited, &self->exited.map.map);
+ lockdep_init_map_crosslock(&self->parked.map.map,
+ "(kthread completion)->parked",
+ create->parked_key, 0);
+ init_completion_map(&self->parked, &self->exited.map.map);
+
current->vfork_done = &self->exited;
/* OK, tell user we're spawned, wait for stop or wakeup */
@@ -272,9 +282,11 @@ static void create_kthread(struct kthread_create_info *create)
}
}
-static __printf(4, 0)
+static __printf(6, 0)
struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
void *data, int node,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
const char namefmt[],
va_list args)
{
@@ -289,6 +301,8 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
create->data = data;
create->node = node;
create->done = &done;
+ create->exited_key = exited_key;
+ create->parked_key = parked_key;
spin_lock(&kthread_create_lock);
list_add_tail(&create->list, &kthread_create_list);
@@ -353,21 +367,24 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
*
* Returns a task_struct or ERR_PTR(-ENOMEM) or ERR_PTR(-EINTR).
*/
-struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
- void *data, int node,
- const char namefmt[],
- ...)
+struct task_struct *_kthread_create_on_node(int (*threadfn)(void *data),
+ void *data, int node,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
+ const char namefmt[],
+ ...)
{
struct task_struct *task;
va_list args;
va_start(args, namefmt);
- task = __kthread_create_on_node(threadfn, data, node, namefmt, args);
+ task = __kthread_create_on_node(threadfn, data, node,
+ exited_key, parked_key, namefmt, args);
va_end(args);
return task;
}
-EXPORT_SYMBOL(kthread_create_on_node);
+EXPORT_SYMBOL(_kthread_create_on_node);
static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mask, long state)
{
@@ -421,14 +438,16 @@ EXPORT_SYMBOL(kthread_bind);
* Description: This helper function creates and names a kernel thread
* The thread will be woken and put into park mode.
*/
-struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
+struct task_struct *_kthread_create_on_cpu(int (*threadfn)(void *data),
void *data, unsigned int cpu,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
const char *namefmt)
{
struct task_struct *p;
- p = kthread_create_on_node(threadfn, data, cpu_to_node(cpu), namefmt,
- cpu);
+ p = _kthread_create_on_node(threadfn, data, cpu_to_node(cpu),
+ exited_key, parked_key, namefmt, cpu);
if (IS_ERR(p))
return p;
kthread_bind(p, cpu);
@@ -649,8 +668,10 @@ int kthread_worker_fn(void *worker_ptr)
}
EXPORT_SYMBOL_GPL(kthread_worker_fn);
-static __printf(3, 0) struct kthread_worker *
+static __printf(5, 0) struct kthread_worker *
__kthread_create_worker(int cpu, unsigned int flags,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
const char namefmt[], va_list args)
{
struct kthread_worker *worker;
@@ -666,8 +687,8 @@ __kthread_create_worker(int cpu, unsigned int flags,
if (cpu >= 0)
node = cpu_to_node(cpu);
- task = __kthread_create_on_node(kthread_worker_fn, worker,
- node, namefmt, args);
+ task = __kthread_create_on_node(kthread_worker_fn, worker, node,
+ exited_key, parked_key, namefmt, args);
if (IS_ERR(task))
goto fail_task;
@@ -694,18 +715,22 @@ __kthread_create_worker(int cpu, unsigned int flags,
* when the worker was SIGKILLed.
*/
struct kthread_worker *
-kthread_create_worker(unsigned int flags, const char namefmt[], ...)
+_kthread_create_worker(unsigned int flags,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
+ const char namefmt[], ...)
{
struct kthread_worker *worker;
va_list args;
va_start(args, namefmt);
- worker = __kthread_create_worker(-1, flags, namefmt, args);
+ worker = __kthread_create_worker(-1, flags, exited_key, parked_key,
+ namefmt, args);
va_end(args);
return worker;
}
-EXPORT_SYMBOL(kthread_create_worker);
+EXPORT_SYMBOL(_kthread_create_worker);
/**
* kthread_create_worker_on_cpu - create a kthread worker and bind it
@@ -725,19 +750,22 @@ EXPORT_SYMBOL(kthread_create_worker);
* when the worker was SIGKILLed.
*/
struct kthread_worker *
-kthread_create_worker_on_cpu(int cpu, unsigned int flags,
+_kthread_create_worker_on_cpu(int cpu, unsigned int flags,
+ struct lock_class_key *exited_key,
+ struct lock_class_key *parked_key,
const char namefmt[], ...)
{
struct kthread_worker *worker;
va_list args;
va_start(args, namefmt);
- worker = __kthread_create_worker(cpu, flags, namefmt, args);
+ worker = __kthread_create_worker(cpu, flags, exited_key, parked_key,
+ namefmt, args);
va_end(args);
return worker;
}
-EXPORT_SYMBOL(kthread_create_worker_on_cpu);
+EXPORT_SYMBOL(_kthread_create_worker_on_cpu);
/*
* Returns true when the work could not be queued at the moment.
--
2.15.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] lockdep: Up MAX_LOCKDEP_CHAINS
2017-11-29 15:41 [PATCH 0/2] lockdep cross-release fallout from -rc1 Daniel Vetter
2017-11-29 15:41 ` [PATCH 1/2] lockdep: finer-grained completion key for kthread Daniel Vetter
@ 2017-11-29 15:41 ` Daniel Vetter
2017-11-30 7:47 ` Peter Zijlstra
1 sibling, 1 reply; 6+ messages in thread
From: Daniel Vetter @ 2017-11-29 15:41 UTC (permalink / raw)
To: LKML, Peter Zijlstra, Ingo Molnar, Thomas Gleixner
Cc: Intel Graphics Development, Tejun Heo, Kees Cook, Daniel Vetter,
Tvrtko Ursulin, Marta Lofstedt, Daniel Vetter
cross-release ftl
>From Chris:
"Fwiw, this isn't cross-release but us reloading the module many times,
creating a whole host of new lockclasses. Even more fun is when the
module gets a slightly different address and the new lock address hashes
into an old lock...
"I did think about a module-hook to revoke the stale lockclasses, but
that still leaves all the hashed chains.
"This particular nuisance was temporarily pushed back by teaching igt not
to reload i915.ko on a whim."
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Marta Lofstedt <marta.lofstedt@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=103707
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
---
kernel/locking/lockdep_internals.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h
index d459d624ba2a..41630a5385c6 100644
--- a/kernel/locking/lockdep_internals.h
+++ b/kernel/locking/lockdep_internals.h
@@ -69,7 +69,7 @@ enum {
#else
#define MAX_LOCKDEP_ENTRIES 32768UL
-#define MAX_LOCKDEP_CHAINS_BITS 16
+#define MAX_LOCKDEP_CHAINS_BITS 17
/*
* Stack-trace: tightly packed array of stack backtrace
--
2.15.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] lockdep: Up MAX_LOCKDEP_CHAINS
2017-11-29 15:41 ` [PATCH 2/2] lockdep: Up MAX_LOCKDEP_CHAINS Daniel Vetter
@ 2017-11-30 7:47 ` Peter Zijlstra
2017-11-30 8:08 ` Daniel Vetter
0 siblings, 1 reply; 6+ messages in thread
From: Peter Zijlstra @ 2017-11-30 7:47 UTC (permalink / raw)
To: Daniel Vetter
Cc: LKML, Ingo Molnar, Thomas Gleixner, Intel Graphics Development,
Tejun Heo, Kees Cook, Tvrtko Ursulin, Marta Lofstedt,
Daniel Vetter
On Wed, Nov 29, 2017 at 04:41:45PM +0100, Daniel Vetter wrote:
> cross-release ftl
>
> From Chris:
>
> "Fwiw, this isn't cross-release but us reloading the module many times,
> creating a whole host of new lockclasses. Even more fun is when the
> module gets a slightly different address and the new lock address hashes
> into an old lock...
Yeah, this is a known issue, just reboot.
> "I did think about a module-hook to revoke the stale lockclasses, but
> that still leaves all the hashed chains.
Its an absolute royal pain to remove all the resources consumed by a
module, and if you manage you then have to deal with fragmented storage
-- that is, we need to go keep track of which entries are used.
Its a giant heap of complexity that's just not worth it.
Given all that, I don't see why we should up this. Just don't reload
modules (or better, don't use modules at all).
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] lockdep: Up MAX_LOCKDEP_CHAINS
2017-11-30 7:47 ` Peter Zijlstra
@ 2017-11-30 8:08 ` Daniel Vetter
0 siblings, 0 replies; 6+ messages in thread
From: Daniel Vetter @ 2017-11-30 8:08 UTC (permalink / raw)
To: Peter Zijlstra
Cc: Daniel Vetter, LKML, Ingo Molnar, Thomas Gleixner,
Intel Graphics Development, Tejun Heo, Kees Cook, Tvrtko Ursulin,
Marta Lofstedt, Daniel Vetter
On Thu, Nov 30, 2017 at 08:47:18AM +0100, Peter Zijlstra wrote:
> On Wed, Nov 29, 2017 at 04:41:45PM +0100, Daniel Vetter wrote:
> > cross-release ftl
> >
> > From Chris:
> >
> > "Fwiw, this isn't cross-release but us reloading the module many times,
> > creating a whole host of new lockclasses. Even more fun is when the
> > module gets a slightly different address and the new lock address hashes
> > into an old lock...
>
> Yeah, this is a known issue, just reboot.
>
> > "I did think about a module-hook to revoke the stale lockclasses, but
> > that still leaves all the hashed chains.
>
> Its an absolute royal pain to remove all the resources consumed by a
> module, and if you manage you then have to deal with fragmented storage
> -- that is, we need to go keep track of which entries are used.
>
> Its a giant heap of complexity that's just not worth it.
>
>
> Given all that, I don't see why we should up this. Just don't reload
> modules (or better, don't use modules at all).
We use excessive amounts of module reloading to validate the failure paths
of driver load. Rebooting takes too much time. I guess we could look into
just rebinding the driver without reloading, that should take the pain off
lockdep. Meanwhile we can carry this locally.
I just included this to check whether you have any plans, thanks for
clarifying that this is not worth it from a core perspective to get fixed.
The real issue we have in CI is the one the first patch papers over.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] lockdep: finer-grained completion key for kthread
2017-11-29 15:41 ` [PATCH 1/2] lockdep: finer-grained completion key for kthread Daniel Vetter
@ 2017-12-04 8:16 ` Daniel Vetter
0 siblings, 0 replies; 6+ messages in thread
From: Daniel Vetter @ 2017-12-04 8:16 UTC (permalink / raw)
To: LKML, Peter Zijlstra, Ingo Molnar, Thomas Gleixner
Cc: Intel Graphics Development, Tejun Heo, Kees Cook, Daniel Vetter,
Tvrtko Ursulin, Marta Lofstedt, Daniel Vetter
On Wed, Nov 29, 2017 at 04:41:44PM +0100, Daniel Vetter wrote:
> Ideally we'd create the key through a macro at the real callers and
> pass it all the way down. This would give us better coverage for cases
> where a bunch of kthreads are created for the same thing.
> But this gets the job done meanwhile and unblocks our CI. Refining
> later on is always possible.
>
> v2:
> - make it compile
> - use the right map (Tvrtko)
>
> v3:
>
> lockdep insist on a static key, so the cheap way didn't work. Wire
> 2 keys through all the callers.
>
> I didn't extend this up to alloc_workqueue because the
> lockdep_invariant_state() call should separate the work functions from
> the workqueue kthread logic and prevent cross-release state from
> leaking between unrelated work queues that happen to reuse the same
> kthreads.
>
> v4: CI found more compile fail :-/
>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: Marta Lofstedt <marta.lofstedt@intel.com>
> References: https://bugs.freedesktop.org/show_bug.cgi?id=103950
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Any comments on this issue here? Is there a real patch we should use
instead of this quick hack?
As mentioned in the cover letter, I don't really have much clue, this is
more an elaborate bug report than anything like a real code submission :-)
Thanks, Daniel
> ---
> include/linux/kthread.h | 48 ++++++++++++++++++++++++++++-----
> kernel/kthread.c | 70 ++++++++++++++++++++++++++++++++++---------------
> 2 files changed, 90 insertions(+), 28 deletions(-)
>
> diff --git a/include/linux/kthread.h b/include/linux/kthread.h
> index c1961761311d..7a9463f0be5c 100644
> --- a/include/linux/kthread.h
> +++ b/include/linux/kthread.h
> @@ -6,10 +6,12 @@
> #include <linux/sched.h>
> #include <linux/cgroup.h>
>
> -__printf(4, 5)
> -struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
> +__printf(6, 7)
> +struct task_struct *_kthread_create_on_node(int (*threadfn)(void *data),
> void *data,
> int node,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> const char namefmt[], ...);
>
> /**
> @@ -25,12 +27,27 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
> */
> #define kthread_create(threadfn, data, namefmt, arg...) \
> kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
> +#define kthread_create_on_node(threadfn, data, node, namefmt, arg...) \
> +({ \
> + static struct lock_class_key __exited_key, __parked_key; \
> + _kthread_create_on_node(threadfn, data, node, &__exited_key, \
> + &__parked_key, namefmt, ##arg); \
> +})
>
>
> -struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
> +struct task_struct *_kthread_create_on_cpu(int (*threadfn)(void *data),
> void *data,
> unsigned int cpu,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> const char *namefmt);
> +#define kthread_create_on_cpu(threadfn, data, cpu, namefmt) \
> +({ \
> + static struct lock_class_key __exited_key, __parked_key; \
> + _kthread_create_on_cpu(threadfn, data, cpu, &__exited_key,\
> + &__parked_key, namefmt); \
> +})
> +
>
> /**
> * kthread_run - create and wake a thread.
> @@ -171,13 +188,30 @@ extern void __kthread_init_worker(struct kthread_worker *worker,
>
> int kthread_worker_fn(void *worker_ptr);
>
> -__printf(2, 3)
> +__printf(4, 5)
> struct kthread_worker *
> -kthread_create_worker(unsigned int flags, const char namefmt[], ...);
> +_kthread_create_worker(unsigned int flags,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> + const char namefmt[], ...);
> +#define kthread_create_worker(flags, namefmt...) \
> +({ \
> + static struct lock_class_key __exited_key, __parked_key; \
> + _kthread_create_worker(flags, &__exited_key, &__parked_key, \
> + ##namefmt); \
> +})
>
> -__printf(3, 4) struct kthread_worker *
> -kthread_create_worker_on_cpu(int cpu, unsigned int flags,
> +__printf(5, 6) struct kthread_worker *
> +_kthread_create_worker_on_cpu(int cpu, unsigned int flags,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> const char namefmt[], ...);
> +#define kthread_create_worker_on_cpu(cpu, flags, namefmt...) \
> +({ \
> + static struct lock_class_key __exited_key, __parked_key; \
> + _kthread_create_worker_on_cpu(cpu, flags, &__exited_key, &__parked_key,\
> + ##namefmt); \
> +})
>
> bool kthread_queue_work(struct kthread_worker *worker,
> struct kthread_work *work);
> diff --git a/kernel/kthread.c b/kernel/kthread.c
> index cd50e99202b0..9022806818fc 100644
> --- a/kernel/kthread.c
> +++ b/kernel/kthread.c
> @@ -32,6 +32,7 @@ struct kthread_create_info
> int (*threadfn)(void *data);
> void *data;
> int node;
> + struct lock_class_key *exited_key, *parked_key;
>
> /* Result passed back to kthread_create() from kthreadd. */
> struct task_struct *result;
> @@ -221,8 +222,17 @@ static int kthread(void *_create)
> }
>
> self->data = data;
> - init_completion(&self->exited);
> - init_completion(&self->parked);
> + /* these two completions are shared with all kthread, which is bonghist
> + * imo */
> + lockdep_init_map_crosslock(&self->exited.map.map,
> + "(kthread completion)->exited",
> + create->exited_key, 0);
> + init_completion_map(&self->exited, &self->exited.map.map);
> + lockdep_init_map_crosslock(&self->parked.map.map,
> + "(kthread completion)->parked",
> + create->parked_key, 0);
> + init_completion_map(&self->parked, &self->exited.map.map);
> +
> current->vfork_done = &self->exited;
>
> /* OK, tell user we're spawned, wait for stop or wakeup */
> @@ -272,9 +282,11 @@ static void create_kthread(struct kthread_create_info *create)
> }
> }
>
> -static __printf(4, 0)
> +static __printf(6, 0)
> struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
> void *data, int node,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> const char namefmt[],
> va_list args)
> {
> @@ -289,6 +301,8 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
> create->data = data;
> create->node = node;
> create->done = &done;
> + create->exited_key = exited_key;
> + create->parked_key = parked_key;
>
> spin_lock(&kthread_create_lock);
> list_add_tail(&create->list, &kthread_create_list);
> @@ -353,21 +367,24 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
> *
> * Returns a task_struct or ERR_PTR(-ENOMEM) or ERR_PTR(-EINTR).
> */
> -struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
> - void *data, int node,
> - const char namefmt[],
> - ...)
> +struct task_struct *_kthread_create_on_node(int (*threadfn)(void *data),
> + void *data, int node,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> + const char namefmt[],
> + ...)
> {
> struct task_struct *task;
> va_list args;
>
> va_start(args, namefmt);
> - task = __kthread_create_on_node(threadfn, data, node, namefmt, args);
> + task = __kthread_create_on_node(threadfn, data, node,
> + exited_key, parked_key, namefmt, args);
> va_end(args);
>
> return task;
> }
> -EXPORT_SYMBOL(kthread_create_on_node);
> +EXPORT_SYMBOL(_kthread_create_on_node);
>
> static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mask, long state)
> {
> @@ -421,14 +438,16 @@ EXPORT_SYMBOL(kthread_bind);
> * Description: This helper function creates and names a kernel thread
> * The thread will be woken and put into park mode.
> */
> -struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
> +struct task_struct *_kthread_create_on_cpu(int (*threadfn)(void *data),
> void *data, unsigned int cpu,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> const char *namefmt)
> {
> struct task_struct *p;
>
> - p = kthread_create_on_node(threadfn, data, cpu_to_node(cpu), namefmt,
> - cpu);
> + p = _kthread_create_on_node(threadfn, data, cpu_to_node(cpu),
> + exited_key, parked_key, namefmt, cpu);
> if (IS_ERR(p))
> return p;
> kthread_bind(p, cpu);
> @@ -649,8 +668,10 @@ int kthread_worker_fn(void *worker_ptr)
> }
> EXPORT_SYMBOL_GPL(kthread_worker_fn);
>
> -static __printf(3, 0) struct kthread_worker *
> +static __printf(5, 0) struct kthread_worker *
> __kthread_create_worker(int cpu, unsigned int flags,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> const char namefmt[], va_list args)
> {
> struct kthread_worker *worker;
> @@ -666,8 +687,8 @@ __kthread_create_worker(int cpu, unsigned int flags,
> if (cpu >= 0)
> node = cpu_to_node(cpu);
>
> - task = __kthread_create_on_node(kthread_worker_fn, worker,
> - node, namefmt, args);
> + task = __kthread_create_on_node(kthread_worker_fn, worker, node,
> + exited_key, parked_key, namefmt, args);
> if (IS_ERR(task))
> goto fail_task;
>
> @@ -694,18 +715,22 @@ __kthread_create_worker(int cpu, unsigned int flags,
> * when the worker was SIGKILLed.
> */
> struct kthread_worker *
> -kthread_create_worker(unsigned int flags, const char namefmt[], ...)
> +_kthread_create_worker(unsigned int flags,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> + const char namefmt[], ...)
> {
> struct kthread_worker *worker;
> va_list args;
>
> va_start(args, namefmt);
> - worker = __kthread_create_worker(-1, flags, namefmt, args);
> + worker = __kthread_create_worker(-1, flags, exited_key, parked_key,
> + namefmt, args);
> va_end(args);
>
> return worker;
> }
> -EXPORT_SYMBOL(kthread_create_worker);
> +EXPORT_SYMBOL(_kthread_create_worker);
>
> /**
> * kthread_create_worker_on_cpu - create a kthread worker and bind it
> @@ -725,19 +750,22 @@ EXPORT_SYMBOL(kthread_create_worker);
> * when the worker was SIGKILLed.
> */
> struct kthread_worker *
> -kthread_create_worker_on_cpu(int cpu, unsigned int flags,
> +_kthread_create_worker_on_cpu(int cpu, unsigned int flags,
> + struct lock_class_key *exited_key,
> + struct lock_class_key *parked_key,
> const char namefmt[], ...)
> {
> struct kthread_worker *worker;
> va_list args;
>
> va_start(args, namefmt);
> - worker = __kthread_create_worker(cpu, flags, namefmt, args);
> + worker = __kthread_create_worker(cpu, flags, exited_key, parked_key,
> + namefmt, args);
> va_end(args);
>
> return worker;
> }
> -EXPORT_SYMBOL(kthread_create_worker_on_cpu);
> +EXPORT_SYMBOL(_kthread_create_worker_on_cpu);
>
> /*
> * Returns true when the work could not be queued at the moment.
> --
> 2.15.0
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-12-04 8:16 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-11-29 15:41 [PATCH 0/2] lockdep cross-release fallout from -rc1 Daniel Vetter
2017-11-29 15:41 ` [PATCH 1/2] lockdep: finer-grained completion key for kthread Daniel Vetter
2017-12-04 8:16 ` Daniel Vetter
2017-11-29 15:41 ` [PATCH 2/2] lockdep: Up MAX_LOCKDEP_CHAINS Daniel Vetter
2017-11-30 7:47 ` Peter Zijlstra
2017-11-30 8:08 ` Daniel Vetter
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