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9156e54576
30482 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Kobe Wu
|
9156e54576 |
locking/lockdep: increase size of counters for lockdep statistics
When system has been running for a long time, signed integer counters are not enough for some lockdep statistics. Using unsigned long counters can satisfy the requirement. Besides, most of lockdep statistics are unsigned. It is better to use unsigned int instead of int. Remove unused variables. - max_recursion_depth - nr_cyclic_check_recursions - nr_find_usage_forwards_recursions - nr_find_usage_backwards_recursions Signed-off-by: Kobe Wu <kobe-cp.wu@mediatek.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <linux-mediatek@lists.infradead.org> Cc: <wsd_upstream@mediatek.com> Cc: Eason Lin <eason-yh.lin@mediatek.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/1561365348-16050-1-git-send-email-kobe-cp.wu@mediatek.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Arnd Bergmann
|
886532aee3 |
locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING
The last cleanup patch triggered another issue, as now another function
should be moved into the same section:
kernel/locking/lockdep.c:3580:12: error: 'mark_lock' defined but not used [-Werror=unused-function]
static int mark_lock(struct task_struct *curr, struct held_lock *this,
Move mark_lock() into the same #ifdef section as its only caller, and
remove the now-unused mark_lock_irq() stub helper.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yuyang Du <duyuyang@gmail.com>
Fixes:
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Peter Zijlstra
|
8dc2d993cf |
x86/percpu, sched/fair: Avoid local_clock()
Nadav reported that code-gen changed because of the this_cpu_*() constraints, avoid this for select_idle_cpu() because that runs with preemption (and IRQs) disabled anyway. Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Waiman Long
|
a15ea1a35f |
locking/rwsem: Guard against making count negative
The upper bits of the count field is used as reader count. When sufficient number of active readers are present, the most significant bit will be set and the count becomes negative. If the number of active readers keep on piling up, we may eventually overflow the reader counts. This is not likely to happen unless the number of bits reserved for reader count is reduced because those bits are need for other purpose. To prevent this count overflow from happening, the most significant bit is now treated as a guard bit (RWSEM_FLAG_READFAIL). Read-lock attempts will now fail for both the fast and slow paths whenever this bit is set. So all those extra readers will be put to sleep in the wait list. Wakeup will not happen until the reader count reaches 0. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Link: https://lkml.kernel.org/r/20190520205918.22251-17-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Waiman Long
|
5cfd92e12e |
locking/rwsem: Adaptive disabling of reader optimistic spinning
Reader optimistic spinning is helpful when the reader critical section
is short and there aren't that many readers around. It makes readers
relatively more preferred than writers. When a writer times out spinning
on a reader-owned lock and set the nospinnable bits, there are two main
reasons for that.
1) The reader critical section is long, perhaps the task sleeps after
acquiring the read lock.
2) There are just too many readers contending the lock causing it to
take a while to service all of them.
In the former case, long reader critical section will impede the progress
of writers which is usually more important for system performance.
In the later case, reader optimistic spinning tends to make the reader
groups that contain readers that acquire the lock together smaller
leading to more of them. That may hurt performance in some cases. In
other words, the setting of nonspinnable bits indicates that reader
optimistic spinning may not be helpful for those workloads that cause it.
Therefore, any writers that have observed the setting of the writer
nonspinnable bit for a given rwsem after they fail to acquire the lock
via optimistic spinning will set the reader nonspinnable bit once they
acquire the write lock. Similarly, readers that observe the setting
of reader nonspinnable bit at slowpath entry will also set the reader
nonspinnable bit when they acquire the read lock via the wakeup path.
Once the reader nonspinnable bit is on, it will only be reset when
a writer is able to acquire the rwsem in the fast path or somehow a
reader or writer in the slowpath doesn't observe the nonspinable bit.
This is to discourage reader optmistic spinning on that particular
rwsem and make writers more preferred. This adaptive disabling of reader
optimistic spinning will alleviate some of the negative side effect of
this feature.
In addition, this patch tries to make readers in the spinning queue
follow the phase-fair principle after quitting optimistic spinning
by checking if another reader has somehow acquired a read lock after
this reader enters the optimistic spinning queue. If so and the rwsem
is still reader-owned, this reader is in the right read-phase and can
attempt to acquire the lock.
On a 2-socket 40-core 80-thread Skylake system, the page_fault1 test of
the will-it-scale benchmark was run with various number of threads. The
number of operations done before reader optimistic spinning patches,
this patch and after this patch were:
Threads Before rspin Before patch After patch %change
------- ------------ ------------ ----------- -------
20 5541068
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Waiman Long
|
7d43f1ce9d |
locking/rwsem: Enable time-based spinning on reader-owned rwsem
When the rwsem is owned by reader, writers stop optimistic spinning
simply because there is no easy way to figure out if all the readers
are actively running or not. However, there are scenarios where
the readers are unlikely to sleep and optimistic spinning can help
performance.
This patch provides a simple mechanism for spinning on a reader-owned
rwsem by a writer. It is a time threshold based spinning where the
allowable spinning time can vary from 10us to 25us depending on the
condition of the rwsem.
When the time threshold is exceeded, the nonspinnable bits will be set
in the owner field to indicate that no more optimistic spinning will
be allowed on this rwsem until it becomes writer owned again. Not even
readers is allowed to acquire the reader-locked rwsem by optimistic
spinning for fairness.
We also want a writer to acquire the lock after the readers hold the
lock for a relatively long time. In order to give preference to writers
under such a circumstance, the single RWSEM_NONSPINNABLE bit is now split
into two - one for reader and one for writer. When optimistic spinning
is disabled, both bits will be set. When the reader count drop down
to 0, the writer nonspinnable bit will be cleared to allow writers to
spin on the lock, but not the readers. When a writer acquires the lock,
it will write its own task structure pointer into sem->owner and clear
the reader nonspinnable bit in the process.
The time taken for each iteration of the reader-owned rwsem spinning
loop varies. Below are sample minimum elapsed times for 16 iterations
of the loop.
System Time for 16 Iterations
------ ----------------------
1-socket Skylake ~800ns
4-socket Broadwell ~300ns
2-socket ThunderX2 (arm64) ~250ns
When the lock cacheline is contended, we can see up to almost 10X
increase in elapsed time. So 25us will be at most 500, 1300 and 1600
iterations for each of the above systems.
With a locking microbenchmark running on 5.1 based kernel, the total
locking rates (in kops/s) on a 8-socket IvyBridge-EX system with
equal numbers of readers and writers before and after this patch were
as follows:
# of Threads Pre-patch Post-patch
------------ --------- ----------
2 1,759 6,684
4 1,684 6,738
8 1,074 7,222
16 900 7,163
32 458 7,316
64 208 520
128 168 425
240 143 474
This patch gives a big boost in performance for mixed reader/writer
workloads.
With 32 locking threads, the rwsem lock event data were:
rwsem_opt_fail=79850
rwsem_opt_nospin=5069
rwsem_opt_rlock=597484
rwsem_opt_wlock=957339
rwsem_sleep_reader=57782
rwsem_sleep_writer=55663
With 64 locking threads, the data looked like:
rwsem_opt_fail=346723
rwsem_opt_nospin=6293
rwsem_opt_rlock=1127119
rwsem_opt_wlock=1400628
rwsem_sleep_reader=308201
rwsem_sleep_writer=72281
So a lot more threads acquired the lock in the slowpath and more threads
went to sleep.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Link: https://lkml.kernel.org/r/20190520205918.22251-15-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Waiman Long
|
94a9717b3c |
locking/rwsem: Make rwsem->owner an atomic_long_t
The rwsem->owner contains not just the task structure pointer, it also holds some flags for storing the current state of the rwsem. Some of the flags may have to be atomically updated. To reflect the new reality, the owner is now changed to an atomic_long_t type. New helper functions are added to properly separate out the task structure pointer and the embedded flags. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Link: https://lkml.kernel.org/r/20190520205918.22251-14-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Waiman Long
|
cf69482d62 |
locking/rwsem: Enable readers spinning on writer
This patch enables readers to optimistically spin on a
rwsem when it is owned by a writer instead of going to sleep
directly. The rwsem_can_spin_on_owner() function is extracted
out of rwsem_optimistic_spin() and is called directly by
rwsem_down_read_slowpath() and rwsem_down_write_slowpath().
With a locking microbenchmark running on 5.1 based kernel, the total
locking rates (in kops/s) on a 8-socket IvyBrige-EX system with equal
numbers of readers and writers before and after the patch were as
follows:
# of Threads Pre-patch Post-patch
------------ --------- ----------
4 1,674 1,684
8 1,062 1,074
16 924 900
32 300 458
64 195 208
128 164 168
240 149 143
The performance change wasn't significant in this case, but this change
is required by a follow-on patch.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Link: https://lkml.kernel.org/r/20190520205918.22251-13-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Waiman Long
|
02f1082b00 |
locking/rwsem: Clarify usage of owner's nonspinaable bit
Bit 1 of sem->owner (RWSEM_ANONYMOUSLY_OWNED) is used to designate an anonymous owner - readers or an anonymous writer. The setting of this anonymous bit is used as an indicator that optimistic spinning cannot be done on this rwsem. With the upcoming reader optimistic spinning patches, a reader-owned rwsem can be spinned on for a limit period of time. We still need this bit to indicate a rwsem is nonspinnable, but not setting this bit loses its meaning that the owner is known. So rename the bit to RWSEM_NONSPINNABLE to clarify its meaning. This patch also fixes a DEBUG_RWSEMS_WARN_ON() bug in __up_write(). Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Link: https://lkml.kernel.org/r/20190520205918.22251-12-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Waiman Long
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d3681e269f |
locking/rwsem: Wake up almost all readers in wait queue
When the front of the wait queue is a reader, other readers
immediately following the first reader will also be woken up at the
same time. However, if there is a writer in between. Those readers
behind the writer will not be woken up.
Because of optimistic spinning, the lock acquisition order is not FIFO
anyway. The lock handoff mechanism will ensure that lock starvation
will not happen.
Assuming that the lock hold times of the other readers still in the
queue will be about the same as the readers that are being woken up,
there is really not much additional cost other than the additional
latency due to the wakeup of additional tasks by the waker. Therefore
all the readers up to a maximum of 256 in the queue are woken up when
the first waiter is a reader to improve reader throughput. This is
somewhat similar in concept to a phase-fair R/W lock.
With a locking microbenchmark running on 5.1 based kernel, the total
locking rates (in kops/s) on a 8-socket IvyBridge-EX system with
equal numbers of readers and writers before and after this patch were
as follows:
# of Threads Pre-Patch Post-patch
------------ --------- ----------
4 1,641 1,674
8 731 1,062
16 564 924
32 78 300
64 38 195
240 50 149
There is no performance gain at low contention level. At high contention
level, however, this patch gives a pretty decent performance boost.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Link: https://lkml.kernel.org/r/20190520205918.22251-11-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Waiman Long
|
990fa7384a |
locking/rwsem: More optimal RT task handling of null owner
An RT task can do optimistic spinning only if the lock holder is
actually running. If the state of the lock holder isn't known, there
is a possibility that high priority of the RT task may block forward
progress of the lock holder if it happens to reside on the same CPU.
This will lead to deadlock. So we have to make sure that an RT task
will not spin on a reader-owned rwsem.
When the owner is temporarily set to NULL, there are two cases
where we may want to continue spinning:
1) The lock owner is in the process of releasing the lock, sem->owner
is cleared but the lock has not been released yet.
2) The lock was free and owner cleared, but another task just comes
in and acquire the lock before we try to get it. The new owner may
be a spinnable writer.
So an RT task is now made to retry one more time to see if it can
acquire the lock or continue spinning on the new owning writer.
When testing on a 8-socket IvyBridge-EX system, the one additional retry
seems to improve locking performance of RT write locking threads under
heavy contentions. The table below shows the locking rates (in kops/s)
with various write locking threads before and after the patch.
Locking threads Pre-patch Post-patch
--------------- --------- -----------
4 2,753 2,608
8 2,529 2,520
16 1,727 1,918
32 1,263 1,956
64 889 1,343
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Link: https://lkml.kernel.org/r/20190520205918.22251-10-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Waiman Long
|
00f3c5a3df |
locking/rwsem: Always release wait_lock before waking up tasks
With the use of wake_q, we can do task wakeups without holding the wait_lock. There is one exception in the rwsem code, though. It is when the writer in the slowpath detects that there are waiters ahead but the rwsem is not held by a writer. This can lead to a long wait_lock hold time especially when a large number of readers are to be woken up. Remediate this situation by releasing the wait_lock before waking up tasks and re-acquiring it afterward. The rwsem_try_write_lock() function is also modified to read the rwsem count directly to avoid stale count value. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Link: https://lkml.kernel.org/r/20190520205918.22251-9-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Waiman Long
|
4f23dbc1e6 |
locking/rwsem: Implement lock handoff to prevent lock starvation
Because of writer lock stealing, it is possible that a constant stream of incoming writers will cause a waiting writer or reader to wait indefinitely leading to lock starvation. This patch implements a lock handoff mechanism to disable lock stealing and force lock handoff to the first waiter or waiters (for readers) in the queue after at least a 4ms waiting period unless it is a RT writer task which doesn't need to wait. The waiting period is used to avoid discouraging lock stealing too much to affect performance. The setting and clearing of the handoff bit is serialized by the wait_lock. So racing is not possible. A rwsem microbenchmark was run for 5 seconds on a 2-socket 40-core 80-thread Skylake system with a v5.1 based kernel and 240 write_lock threads with 5us sleep critical section. Before the patch, the min/mean/max numbers of locking operations for the locking threads were 1/7,792/173,696. After the patch, the figures became 5,842/6,542/7,458. It can be seen that the rwsem became much more fair, though there was a drop of about 16% in the mean locking operations done which was a tradeoff of having better fairness. Making the waiter set the handoff bit right after the first wakeup can impact performance especially with a mixed reader/writer workload. With the same microbenchmark with short critical section and equal number of reader and writer threads (40/40), the reader/writer locking operation counts with the current patch were: 40 readers, Iterations Min/Mean/Max = 1,793/1,794/1,796 40 writers, Iterations Min/Mean/Max = 1,793/34,956/86,081 By making waiter set handoff bit immediately after wakeup: 40 readers, Iterations Min/Mean/Max = 43/44/46 40 writers, Iterations Min/Mean/Max = 43/1,263/3,191 Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Link: https://lkml.kernel.org/r/20190520205918.22251-8-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Waiman Long
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3f6d517a3e |
locking/rwsem: Make rwsem_spin_on_owner() return owner state
This patch modifies rwsem_spin_on_owner() to return four possible values to better reflect the state of lock holder which enables us to make a better decision of what to do next. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Link: https://lkml.kernel.org/r/20190520205918.22251-7-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Waiman Long
|
6cef7ff6e4 |
locking/rwsem: Code cleanup after files merging
After merging all the relevant rwsem code into one single file, there
are a number of optimizations and cleanups that can be done:
1) Remove all the EXPORT_SYMBOL() calls for functions that are not
accessed elsewhere.
2) Remove all the __visible tags as none of the functions will be
called from assembly code anymore.
3) Make all the internal functions static.
4) Remove some unneeded blank lines.
5) Remove the intermediate rwsem_down_{read|write}_failed*() functions
and rename __rwsem_down_{read|write}_failed_common() to
rwsem_down_{read|write}_slowpath().
6) Remove "__" prefix of __rwsem_mark_wake().
7) Use atomic_long_try_cmpxchg_acquire() as much as possible.
8) Remove the rwsem_rtrylock and rwsem_wtrylock lock events as they
are not that useful.
That enables the compiler to do better optimization and reduce code
size. The text+data size of rwsem.o on an x86-64 machine with gcc8 was
reduced from 10237 bytes to 5030 bytes with this change.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Link: https://lkml.kernel.org/r/20190520205918.22251-6-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
||
|
Waiman Long
|
5dec94d492 |
locking/rwsem: Merge rwsem.h and rwsem-xadd.c into rwsem.c
Now we only have one implementation of rwsem. Even though we still use xadd to handle reader locking, we use cmpxchg for writer instead. So the filename rwsem-xadd.c is not strictly correct. Also no one outside of the rwsem code need to know the internal implementation other than function prototypes for two internal functions that are called directly from percpu-rwsem.c. So the rwsem-xadd.c and rwsem.h files are now merged into rwsem.c in the following order: <upper part of rwsem.h> <rwsem-xadd.c> <lower part of rwsem.h> <rwsem.c> The rwsem.h file now contains only 2 function declarations for __up_read() and __down_read(). This is a code relocation patch with no code change at all except making __up_read() and __down_read() non-static functions so they can be used by percpu-rwsem.c. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Link: https://lkml.kernel.org/r/20190520205918.22251-5-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Waiman Long
|
64489e7800 |
locking/rwsem: Implement a new locking scheme
The current way of using various reader, writer and waiting biases
in the rwsem code are confusing and hard to understand. I have to
reread the rwsem count guide in the rwsem-xadd.c file from time to
time to remind myself how this whole thing works. It also makes the
rwsem code harder to be optimized.
To make rwsem more sane, a new locking scheme similar to the one in
qrwlock is now being used. The atomic long count has the following
bit definitions:
Bit 0 - writer locked bit
Bit 1 - waiters present bit
Bits 2-7 - reserved for future extension
Bits 8-X - reader count (24/56 bits)
The cmpxchg instruction is now used to acquire the write lock. The read
lock is still acquired with xadd instruction, so there is no change here.
This scheme will allow up to 16M/64P active readers which should be
more than enough. We can always use some more reserved bits if necessary.
With that change, we can deterministically know if a rwsem has been
write-locked. Looking at the count alone, however, one cannot determine
for certain if a rwsem is owned by readers or not as the readers that
set the reader count bits may be in the process of backing out. So we
still need the reader-owned bit in the owner field to be sure.
With a locking microbenchmark running on 5.1 based kernel, the total
locking rates (in kops/s) of the benchmark on a 8-socket 120-core
IvyBridge-EX system before and after the patch were as follows:
Before Patch After Patch
# of Threads wlock rlock wlock rlock
------------ ----- ----- ----- -----
1 30,659 31,341 31,055 31,283
2 8,909 16,457 9,884 17,659
4 9,028 15,823 8,933 20,233
8 8,410 14,212 7,230 17,140
16 8,217 25,240 7,479 24,607
The locking rates of the benchmark on a Power8 system were as follows:
Before Patch After Patch
# of Threads wlock rlock wlock rlock
------------ ----- ----- ----- -----
1 12,963 13,647 13,275 13,601
2 7,570 11,569 7,902 10,829
4 5,232 5,516 5,466 5,435
8 5,233 3,386 5,467 3,168
The locking rates of the benchmark on a 2-socket ARM64 system were
as follows:
Before Patch After Patch
# of Threads wlock rlock wlock rlock
------------ ----- ----- ----- -----
1 21,495 21,046 21,524 21,074
2 5,293 10,502 5,333 10,504
4 5,325 11,463 5,358 11,631
8 5,391 11,712 5,470 11,680
The performance are roughly the same before and after the patch. There
are run-to-run variations in performance. Runs with higher variances
usually have higher throughput.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Link: https://lkml.kernel.org/r/20190520205918.22251-4-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
||
|
Waiman Long
|
5c1ec49b60 |
locking/rwsem: Remove rwsem_wake() wakeup optimization
After the following commit: |
||
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Waiman Long
|
c71fd893f6 |
locking/rwsem: Make owner available even if !CONFIG_RWSEM_SPIN_ON_OWNER
The owner field in the rw_semaphore structure is used primarily for optimistic spinning. However, identifying the rwsem owner can also be helpful in debugging as well as tracing locking related issues when analyzing crash dump. The owner field may also store state information that can be important to the operation of the rwsem. So the owner field is now made a permanent member of the rw_semaphore structure irrespective of CONFIG_RWSEM_SPIN_ON_OWNER. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Link: https://lkml.kernel.org/r/20190520205918.22251-2-longman@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Kobe Wu
|
dd471efe34 |
locking/lockdep: Remove unnecessary DEBUG_LOCKS_WARN_ON()
DEBUG_LOCKS_WARN_ON() will turn off debug_locks and makes print_unlock_imbalance_bug() return directly. Remove a redundant whitespace. Signed-off-by: Kobe Wu <kobe-cp.wu@mediatek.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <linux-mediatek@lists.infradead.org> Cc: <wsd_upstream@mediatek.com> Cc: Eason Lin <eason-yh.lin@mediatek.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/1559217575-30298-1-git-send-email-kobe-cp.wu@mediatek.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Daniel Bristot de Oliveira
|
c2ba8a15f3 |
jump_label: Batch updates if arch supports it
If the architecture supports the batching of jump label updates, use it!
An easy way to see the benefits of this patch is switching the
schedstats on and off. For instance:
-------------------------- %< ----------------------------
#!/bin/sh
while [ true ]; do
sysctl -w kernel.sched_schedstats=1
sleep 2
sysctl -w kernel.sched_schedstats=0
sleep 2
done
-------------------------- >% ----------------------------
while watching the IPI count:
-------------------------- %< ----------------------------
# watch -n1 "cat /proc/interrupts | grep Function"
-------------------------- >% ----------------------------
With the current mode, it is possible to see +- 168 IPIs each 2 seconds,
while with this patch the number of IPIs goes to 3 each 2 seconds.
Regarding the performance impact of this patch set, I made two measurements:
The time to update a key (the task that is causing the change)
The time to run the int3 handler (the side effect on a thread that
hits the code being changed)
The schedstats static key was chosen as the key to being switched on and off.
The reason being is that it is used in more than 56 places, in a hot path. The
change in the schedstats static key will be done with the following command:
while [ true ]; do
sysctl -w kernel.sched_schedstats=1
usleep 500000
sysctl -w kernel.sched_schedstats=0
usleep 500000
done
In this way, they key will be updated twice per second. To force the hit of the
int3 handler, the system will also run a kernel compilation with two jobs per
CPU. The test machine is a two nodes/24 CPUs box with an Intel Xeon processor
@2.27GHz.
Regarding the update part, on average, the regular kernel takes 57 ms to update
the schedstats key, while the kernel with the batch updates takes just 1.4 ms
on average. Although it seems to be too good to be true, it makes sense: the
schedstats key is used in 56 places, so it was expected that it would take
around 56 times to update the keys with the current implementation, as the
IPIs are the most expensive part of the update.
Regarding the int3 handler, the non-batch handler takes 45 ns on average, while
the batch version takes around 180 ns. At first glance, it seems to be a high
value. But it is not, considering that it is doing 56 updates, rather than one!
It is taking four times more, only. This gain is possible because the patch
uses a binary search in the vector: log2(56)=5.8. So, it was expected to have
an overhead within four times.
(voice of tv propaganda) But, that is not all! As the int3 handler keeps on for
a shorter period (because the update part is on for a shorter time), the number
of hits in the int3 handler decreased by 10%.
The question then is: Is it worth paying the price of "135 ns" more in the int3
handler?
Considering that, in this test case, we are saving the handling of 53 IPIs,
that takes more than these 135 ns, it seems to be a meager price to be paid.
Moreover, the test case was forcing the hit of the int3, in practice, it
does not take that often. While the IPI takes place on all CPUs, hitting
the int3 handler or not!
For instance, in an isolated CPU with a process running in user-space
(nohz_full use-case), the chances of hitting the int3 handler is barely zero,
while there is no way to avoid the IPIs. By bounding the IPIs, we are improving
a lot this scenario.
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris von Recklinghausen <crecklin@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Wood <swood@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/acc891dbc2dbc9fd616dd680529a2337b1d1274c.1560325897.git.bristot@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
||
|
Daniel Bristot de Oliveira
|
0f133021bd |
jump_label: Sort entries of the same key by the code
In the batching mode, all the entries of a given key are updated at once. During the update of a key, a hit in the int3 handler will check if the hitting code address belongs to one of these keys. To optimize the search of a given code in the vector of entries being updated, a binary search is used. The binary search relies on the order of the entries of a key by its code. Hence the keys need to be sorted by the code too, so sort the entries of a given key by the code. Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris von Recklinghausen <crecklin@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott Wood <swood@redhat.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/f57ae83e0592418ba269866bb7ade570fc8632e0.1560325897.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Daniel Bristot de Oliveira
|
e1aacb3f4a |
jump_label: Add a jump_label_can_update() helper
Move the check if a jump_entry is valid to a function. No functional change. Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris von Recklinghausen <crecklin@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott Wood <swood@redhat.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/56b69bd3f8e644ed64f2dbde7c088030b8cbe76b.1560325897.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Ingo Molnar
|
410df0c574 |
Linux 5.2-rc5
-----BEGIN PGP SIGNATURE----- iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAl0Gj1MeHHRvcnZhbGRz QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGctkH/0At3+SQPY2JJSy8 i6+TDeytFx9OggeGLPHChRfehkAlvMb/kd34QHnuEvDqUuCAMU6HZQJFKoK9mvFI sDJVayPGDSqpm+iv8qLpMBPShiCXYVnGZeVfOdv36jUswL0k6wHV1pz4avFkDeZa 1F4pmI6O2XRkNTYQawbUaFkAngWUCBG9ECLnHJnuIY6ohShBvjI4+E2JUaht+8gO M2h2b9ieddWmjxV3LTKgsK1v+347RljxdZTWnJ62SCDSEVZvsgSA9W2wnebVhBkJ drSmrFLxNiM+W45mkbUFmQixRSmjv++oRR096fxAnodBxMw0TDxE1RiMQWE6rVvG N6MC6xA= =+B0P -----END PGP SIGNATURE----- Merge tag 'v5.2-rc5' into locking/core, to pick up fixes Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Linus Torvalds
|
efba92d58f |
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"A set of small fixes:
- Repair the ktime_get_coarse() functions so they actually deliver
what they are supposed to: tick granular time stamps. The current
code missed to add the accumulated nanoseconds part of the
timekeeper so the resulting granularity was 1 second.
- Prevent the tracer from infinitely recursing into time getter
functions in the arm architectured timer by marking these functions
notrace
- Fix a trivial compiler warning caused by wrong qualifier ordering"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Repair ktime_get_coarse*() granularity
clocksource/drivers/arm_arch_timer: Don't trace count reader functions
clocksource/drivers/timer-ti-dm: Change to new style declaration
|
||
|
Linus Torvalds
|
6a71398c6a |
This includes the following fixes:
- Out of range read of stack trace output - Fix for NULL pointer dereference in trace_uprobe_create() - Fix to a livepatching / ftrace permission race in the module code - Fix for NULL pointer dereference in free_ftrace_func_mapper() - A couple of build warning clean ups -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXQToxhQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qusmAP4/mmJPgsDchnu5ui0wB8BByzJlsPn8 luXFDuqI4f34zgD+JCmeYbj5LLh98D9XkaaEgP4yz3yKsWeSdwWPCU0vTgo= =M/+E -----END PGP SIGNATURE----- Merge tag 'trace-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: - Out of range read of stack trace output - Fix for NULL pointer dereference in trace_uprobe_create() - Fix to a livepatching / ftrace permission race in the module code - Fix for NULL pointer dereference in free_ftrace_func_mapper() - A couple of build warning clean ups * tag 'trace-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Fix NULL pointer dereference in free_ftrace_func_mapper() module: Fix livepatch/ftrace module text permissions race tracing/uprobe: Fix obsolete comment on trace_uprobe_create() tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create() tracing: Make two symbols static tracing: avoid build warning with HAVE_NOP_MCOUNT tracing: Fix out-of-range read in trace_stack_print() |
||
|
Linus Torvalds
|
0011572c88 |
Merge branch 'for-5.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
"This has an unusually high density of tricky fixes:
- task_get_css() could deadlock when it races against a dying cgroup.
- cgroup.procs didn't list thread group leaders with live threads.
This could mislead readers to think that a cgroup is empty when
it's not. Fixed by making PROCS iterator include dead tasks. I made
a couple mistakes making this change and this pull request contains
a couple follow-up patches.
- When cpusets run out of online cpus, it updates cpusmasks of member
tasks in bizarre ways. Joel improved the behavior significantly"
* 'for-5.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: restore sanity to cpuset_cpus_allowed_fallback()
cgroup: Fix css_task_iter_advance_css_set() cset skip condition
cgroup: css_task_iter_skip()'d iterators must be advanced before accessed
cgroup: Include dying leaders with live threads in PROCS iterations
cgroup: Implement css_task_iter_skip()
cgroup: Call cgroup_release() before __exit_signal()
docs cgroups: add another example size for hugetlb
cgroup: Use css_tryget() instead of css_tryget_online() in task_get_css()
|
||
|
Wei Li
|
04e03d9a61 |
ftrace: Fix NULL pointer dereference in free_ftrace_func_mapper()
The mapper may be NULL when called from register_ftrace_function_probe() with probe->data == NULL. This issue can be reproduced as follow (it may be covered by compiler optimization sometime): / # cat /sys/kernel/debug/tracing/set_ftrace_filter #### all functions enabled #### / # echo foo_bar:dump > /sys/kernel/debug/tracing/set_ftrace_filter [ 206.949100] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 206.952402] Mem abort info: [ 206.952819] ESR = 0x96000006 [ 206.955326] Exception class = DABT (current EL), IL = 32 bits [ 206.955844] SET = 0, FnV = 0 [ 206.956272] EA = 0, S1PTW = 0 [ 206.956652] Data abort info: [ 206.957320] ISV = 0, ISS = 0x00000006 [ 206.959271] CM = 0, WnR = 0 [ 206.959938] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000419f3a000 [ 206.960483] [0000000000000000] pgd=0000000411a87003, pud=0000000411a83003, pmd=0000000000000000 [ 206.964953] Internal error: Oops: 96000006 [#1] SMP [ 206.971122] Dumping ftrace buffer: [ 206.973677] (ftrace buffer empty) [ 206.975258] Modules linked in: [ 206.976631] Process sh (pid: 281, stack limit = 0x(____ptrval____)) [ 206.978449] CPU: 10 PID: 281 Comm: sh Not tainted 5.2.0-rc1+ #17 [ 206.978955] Hardware name: linux,dummy-virt (DT) [ 206.979883] pstate: 60000005 (nZCv daif -PAN -UAO) [ 206.980499] pc : free_ftrace_func_mapper+0x2c/0x118 [ 206.980874] lr : ftrace_count_free+0x68/0x80 [ 206.982539] sp : ffff0000182f3ab0 [ 206.983102] x29: ffff0000182f3ab0 x28: ffff8003d0ec1700 [ 206.983632] x27: ffff000013054b40 x26: 0000000000000001 [ 206.984000] x25: ffff00001385f000 x24: 0000000000000000 [ 206.984394] x23: ffff000013453000 x22: ffff000013054000 [ 206.984775] x21: 0000000000000000 x20: ffff00001385fe28 [ 206.986575] x19: ffff000013872c30 x18: 0000000000000000 [ 206.987111] x17: 0000000000000000 x16: 0000000000000000 [ 206.987491] x15: ffffffffffffffb0 x14: 0000000000000000 [ 206.987850] x13: 000000000017430e x12: 0000000000000580 [ 206.988251] x11: 0000000000000000 x10: cccccccccccccccc [ 206.988740] x9 : 0000000000000000 x8 : ffff000013917550 [ 206.990198] x7 : ffff000012fac2e8 x6 : ffff000012fac000 [ 206.991008] x5 : ffff0000103da588 x4 : 0000000000000001 [ 206.991395] x3 : 0000000000000001 x2 : ffff000013872a28 [ 206.991771] x1 : 0000000000000000 x0 : 0000000000000000 [ 206.992557] Call trace: [ 206.993101] free_ftrace_func_mapper+0x2c/0x118 [ 206.994827] ftrace_count_free+0x68/0x80 [ 206.995238] release_probe+0xfc/0x1d0 [ 206.995555] register_ftrace_function_probe+0x4a8/0x868 [ 206.995923] ftrace_trace_probe_callback.isra.4+0xb8/0x180 [ 206.996330] ftrace_dump_callback+0x50/0x70 [ 206.996663] ftrace_regex_write.isra.29+0x290/0x3a8 [ 206.997157] ftrace_filter_write+0x44/0x60 [ 206.998971] __vfs_write+0x64/0xf0 [ 206.999285] vfs_write+0x14c/0x2f0 [ 206.999591] ksys_write+0xbc/0x1b0 [ 206.999888] __arm64_sys_write+0x3c/0x58 [ 207.000246] el0_svc_common.constprop.0+0x408/0x5f0 [ 207.000607] el0_svc_handler+0x144/0x1c8 [ 207.000916] el0_svc+0x8/0xc [ 207.003699] Code: aa0003f8 a9025bf5 aa0103f5 f946ea80 (f9400303) [ 207.008388] ---[ end trace 7b6d11b5f542bdf1 ]--- [ 207.010126] Kernel panic - not syncing: Fatal exception [ 207.011322] SMP: stopping secondary CPUs [ 207.013956] Dumping ftrace buffer: [ 207.014595] (ftrace buffer empty) [ 207.015632] Kernel Offset: disabled [ 207.017187] CPU features: 0x002,20006008 [ 207.017985] Memory Limit: none [ 207.019825] ---[ end Kernel panic - not syncing: Fatal exception ]--- Link: http://lkml.kernel.org/r/20190606031754.10798-1-liwei391@huawei.com Signed-off-by: Wei Li <liwei391@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> |
||
|
Josh Poimboeuf
|
9f255b632b |
module: Fix livepatch/ftrace module text permissions race
It's possible for livepatch and ftrace to be toggling a module's text
permissions at the same time, resulting in the following panic:
BUG: unable to handle page fault for address: ffffffffc005b1d9
#PF: supervisor write access in kernel mode
#PF: error_code(0x0003) - permissions violation
PGD 3ea0c067 P4D 3ea0c067 PUD 3ea0e067 PMD 3cc13067 PTE 3b8a1061
Oops: 0003 [#1] PREEMPT SMP PTI
CPU: 1 PID: 453 Comm: insmod Tainted: G O K 5.2.0-rc1-a188339ca5 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014
RIP: 0010:apply_relocate_add+0xbe/0x14c
Code: fa 0b 74 21 48 83 fa 18 74 38 48 83 fa 0a 75 40 eb 08 48 83 38 00 74 33 eb 53 83 38 00 75 4e 89 08 89 c8 eb 0a 83 38 00 75 43 <89> 08 48 63 c1 48 39 c8 74 2e eb 48 83 38 00 75 32 48 29 c1 89 08
RSP: 0018:ffffb223c00dbb10 EFLAGS: 00010246
RAX: ffffffffc005b1d9 RBX: 0000000000000000 RCX: ffffffff8b200060
RDX: 000000000000000b RSI: 0000004b0000000b RDI: ffff96bdfcd33000
RBP: ffffb223c00dbb38 R08: ffffffffc005d040 R09: ffffffffc005c1f0
R10: ffff96bdfcd33c40 R11: ffff96bdfcd33b80 R12: 0000000000000018
R13: ffffffffc005c1f0 R14: ffffffffc005e708 R15: ffffffff8b2fbc74
FS: 00007f5f447beba8(0000) GS:ffff96bdff900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc005b1d9 CR3: 000000003cedc002 CR4: 0000000000360ea0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
klp_init_object_loaded+0x10f/0x219
? preempt_latency_start+0x21/0x57
klp_enable_patch+0x662/0x809
? virt_to_head_page+0x3a/0x3c
? kfree+0x8c/0x126
patch_init+0x2ed/0x1000 [livepatch_test02]
? 0xffffffffc0060000
do_one_initcall+0x9f/0x1c5
? kmem_cache_alloc_trace+0xc4/0xd4
? do_init_module+0x27/0x210
do_init_module+0x5f/0x210
load_module+0x1c41/0x2290
? fsnotify_path+0x3b/0x42
? strstarts+0x2b/0x2b
? kernel_read+0x58/0x65
__do_sys_finit_module+0x9f/0xc3
? __do_sys_finit_module+0x9f/0xc3
__x64_sys_finit_module+0x1a/0x1c
do_syscall_64+0x52/0x61
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The above panic occurs when loading two modules at the same time with
ftrace enabled, where at least one of the modules is a livepatch module:
CPU0 CPU1
klp_enable_patch()
klp_init_object_loaded()
module_disable_ro()
ftrace_module_enable()
ftrace_arch_code_modify_post_process()
set_all_modules_text_ro()
klp_write_object_relocations()
apply_relocate_add()
*patches read-only code* - BOOM
A similar race exists when toggling ftrace while loading a livepatch
module.
Fix it by ensuring that the livepatch and ftrace code patching
operations -- and their respective permissions changes -- are protected
by the text_mutex.
Link: http://lkml.kernel.org/r/ab43d56ab909469ac5d2520c5d944ad6d4abd476.1560474114.git.jpoimboe@redhat.com
Reported-by: Johannes Erdfelt <johannes@erdfelt.com>
Fixes:
|
||
|
Eiichi Tsukata
|
a4158345ec |
tracing/uprobe: Fix obsolete comment on trace_uprobe_create()
Commit
|
||
|
Eiichi Tsukata
|
f01098c74b |
tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create()
Just like the case of commit |
||
|
YueHaibing
|
ff585c5b9a |
tracing: Make two symbols static
Fix sparse warnings: kernel/trace/trace.c:6927:24: warning: symbol 'get_tracing_log_err' was not declared. Should it be static? kernel/trace/trace.c:8196:15: warning: symbol 'trace_instance_dir' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20190614153210.24424-1-yuehaibing@huawei.com Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> |
||
|
Vasily Gorbik
|
cbdaeaf050 |
tracing: avoid build warning with HAVE_NOP_MCOUNT
Selecting HAVE_NOP_MCOUNT enables -mnop-mcount (if gcc supports it)
and sets CC_USING_NOP_MCOUNT. Reuse __is_defined (which is suitable for
testing CC_USING_* defines) to avoid conditional compilation and fix
the following gcc 9 warning on s390:
kernel/trace/ftrace.c:2514:1: warning: ‘ftrace_code_disable’ defined
but not used [-Wunused-function]
Link: http://lkml.kernel.org/r/patch.git-1a82d13f33ac.your-ad-here.call-01559732716-ext-6629@work.hours
Fixes:
|
||
|
Eiichi Tsukata
|
becf33f694 |
tracing: Fix out-of-range read in trace_stack_print()
Puts range check before dereferencing the pointer.
Reproducer:
# echo stacktrace > trace_options
# echo 1 > events/enable
# cat trace > /dev/null
KASAN report:
==================================================================
BUG: KASAN: use-after-free in trace_stack_print+0x26b/0x2c0
Read of size 8 at addr ffff888069d20000 by task cat/1953
CPU: 0 PID: 1953 Comm: cat Not tainted 5.2.0-rc3+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
Call Trace:
dump_stack+0x8a/0xce
print_address_description+0x60/0x224
? trace_stack_print+0x26b/0x2c0
? trace_stack_print+0x26b/0x2c0
__kasan_report.cold+0x1a/0x3e
? trace_stack_print+0x26b/0x2c0
kasan_report+0xe/0x20
trace_stack_print+0x26b/0x2c0
print_trace_line+0x6ea/0x14d0
? tracing_buffers_read+0x700/0x700
? trace_find_next_entry_inc+0x158/0x1d0
s_show+0xea/0x310
seq_read+0xaa7/0x10e0
? seq_escape+0x230/0x230
__vfs_read+0x7c/0x100
vfs_read+0x16c/0x3a0
ksys_read+0x121/0x240
? kernel_write+0x110/0x110
? perf_trace_sys_enter+0x8a0/0x8a0
? syscall_slow_exit_work+0xa9/0x410
do_syscall_64+0xb7/0x390
? prepare_exit_to_usermode+0x165/0x200
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f867681f910
Code: b6 fe ff ff 48 8d 3d 0f be 08 00 48 83 ec 08 e8 06 db 01 00 66 0f 1f 44 00 00 83 3d f9 2d 2c 00 00 75 10 b8 00 00 00 00 04
RSP: 002b:00007ffdabf23488 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f867681f910
RDX: 0000000000020000 RSI: 00007f8676cde000 RDI: 0000000000000003
RBP: 00007f8676cde000 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000871 R11: 0000000000000246 R12: 00007f8676cde000
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000000ec0
Allocated by task 1214:
save_stack+0x1b/0x80
__kasan_kmalloc.constprop.0+0xc2/0xd0
kmem_cache_alloc+0xaf/0x1a0
getname_flags+0xd2/0x5b0
do_sys_open+0x277/0x5a0
do_syscall_64+0xb7/0x390
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Freed by task 1214:
save_stack+0x1b/0x80
__kasan_slab_free+0x12c/0x170
kmem_cache_free+0x8a/0x1c0
putname+0xe1/0x120
do_sys_open+0x2c5/0x5a0
do_syscall_64+0xb7/0x390
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff888069d20000
which belongs to the cache names_cache of size 4096
The buggy address is located 0 bytes inside of
4096-byte region [ffff888069d20000, ffff888069d21000)
The buggy address belongs to the page:
page:ffffea0001a74800 refcount:1 mapcount:0 mapping:ffff88806ccd1380 index:0x0 compound_mapcount: 0
flags: 0x100000000010200(slab|head)
raw: 0100000000010200 dead000000000100 dead000000000200 ffff88806ccd1380
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888069d1ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888069d1ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888069d20000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888069d20080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888069d20100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Link: http://lkml.kernel.org/r/20190610040016.5598-1-devel@etsukata.com
Fixes:
|
||
|
Thomas Gleixner
|
e3ff9c3678 |
timekeeping: Repair ktime_get_coarse*() granularity
Jason reported that the coarse ktime based time getters advance only once
per second and not once per tick as advertised.
The code reads only the monotonic base time, which advances once per
second. The nanoseconds are accumulated on every tick in xtime_nsec up to
a second and the regular time getters take this nanoseconds offset into
account, but the ktime_get_coarse*() implementation fails to do so.
Add the accumulated xtime_nsec value to the monotonic base time to get the
proper per tick advancing coarse tinme.
Fixes:
|
||
|
Dan Williams
|
50f44ee724 |
mm/devm_memremap_pages: fix final page put race
Logan noticed that devm_memremap_pages_release() kills the percpu_ref
drops all the page references that were acquired at init and then
immediately proceeds to unplug, arch_remove_memory(), the backing pages
for the pagemap. If for some reason device shutdown actually collides
with a busy / elevated-ref-count page then arch_remove_memory() should
be deferred until after that reference is dropped.
As it stands the "wait for last page ref drop" happens *after*
devm_memremap_pages_release() returns, which is obviously too late and
can lead to crashes.
Fix this situation by assigning the responsibility to wait for the
percpu_ref to go idle to devm_memremap_pages() with a new ->cleanup()
callback. Implement the new cleanup callback for all
devm_memremap_pages() users: pmem, devdax, hmm, and p2pdma.
Link: http://lkml.kernel.org/r/155727339156.292046.5432007428235387859.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes:
|
||
|
Dan Williams
|
2e3f139e8e |
mm/devm_memremap_pages: introduce devm_memunmap_pages
Use the new devm_release_action() facility to allow devm_memremap_pages_release() to be manually triggered. Link: http://lkml.kernel.org/r/155727337088.292046.5774214552136776763.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Joel Savitz
|
d477f8c202 |
cpuset: restore sanity to cpuset_cpus_allowed_fallback()
In the case that a process is constrained by taskset(1) (i.e. sched_setaffinity(2)) to a subset of available cpus, and all of those are subsequently offlined, the scheduler will set tsk->cpus_allowed to the current value of task_cs(tsk)->effective_cpus. This is done via a call to do_set_cpus_allowed() in the context of cpuset_cpus_allowed_fallback() made by the scheduler when this case is detected. This is the only call made to cpuset_cpus_allowed_fallback() in the latest mainline kernel. However, this is not sane behavior. I will demonstrate this on a system running the latest upstream kernel with the following initial configuration: # grep -i cpu /proc/$$/status Cpus_allowed: ffffffff,fffffff Cpus_allowed_list: 0-63 (Where cpus 32-63 are provided via smt.) If we limit our current shell process to cpu2 only and then offline it and reonline it: # taskset -p 4 $$ pid 2272's current affinity mask: ffffffffffffffff pid 2272's new affinity mask: 4 # echo off > /sys/devices/system/cpu/cpu2/online # dmesg | tail -3 [ 2195.866089] process 2272 (bash) no longer affine to cpu2 [ 2195.872700] IRQ 114: no longer affine to CPU2 [ 2195.879128] smpboot: CPU 2 is now offline # echo on > /sys/devices/system/cpu/cpu2/online # dmesg | tail -1 [ 2617.043572] smpboot: Booting Node 0 Processor 2 APIC 0x4 We see that our current process now has an affinity mask containing every cpu available on the system _except_ the one we originally constrained it to: # grep -i cpu /proc/$$/status Cpus_allowed: ffffffff,fffffffb Cpus_allowed_list: 0-1,3-63 This is not sane behavior, as the scheduler can now not only place the process on previously forbidden cpus, it can't even schedule it on the cpu it was originally constrained to! Other cases result in even more exotic affinity masks. Take for instance a process with an affinity mask containing only cpus provided by smt at the moment that smt is toggled, in a configuration such as the following: # taskset -p f000000000 $$ # grep -i cpu /proc/$$/status Cpus_allowed: 000000f0,00000000 Cpus_allowed_list: 36-39 A double toggle of smt results in the following behavior: # echo off > /sys/devices/system/cpu/smt/control # echo on > /sys/devices/system/cpu/smt/control # grep -i cpus /proc/$$/status Cpus_allowed: ffffff00,ffffffff Cpus_allowed_list: 0-31,40-63 This is even less sane than the previous case, as the new affinity mask excludes all smt-provided cpus with ids less than those that were previously in the affinity mask, as well as those that were actually in the mask. With this patch applied, both of these cases end in the following state: # grep -i cpu /proc/$$/status Cpus_allowed: ffffffff,ffffffff Cpus_allowed_list: 0-63 The original policy is discarded. Though not ideal, it is the simplest way to restore sanity to this fallback case without reinventing the cpuset wheel that rolls down the kernel just fine in cgroup v2. A user who wishes for the previous affinity mask to be restored in this fallback case can use that mechanism instead. This patch modifies scheduler behavior by instead resetting the mask to task_cs(tsk)->cpus_allowed by default, and cpu_possible mask in legacy mode. I tested the cases above on both modes. Note that the scheduler uses this fallback mechanism if and only if _every_ other valid avenue has been traveled, and it is the last resort before calling BUG(). Suggested-by: Waiman Long <longman@redhat.com> Suggested-by: Phil Auld <pauld@redhat.com> Signed-off-by: Joel Savitz <jsavitz@redhat.com> Acked-by: Phil Auld <pauld@redhat.com> Acked-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org> |
||
|
Linus Torvalds
|
aa7235483a |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ptrace fixes from Eric Biederman:
"This is just two very minor fixes:
- prevent ptrace from reading unitialized kernel memory found twice
by syzkaller
- restore a missing smp_rmb in ptrace_may_access and add comment tp
it so it is not removed by accident again.
Apologies for being a little slow about getting this to you, I am
still figuring out how to develop with a little baby in the house"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ptrace: restore smp_rmb() in __ptrace_may_access()
signal/ptrace: Don't leak unitialized kernel memory with PTRACE_PEEK_SIGINFO
|
||
|
Jann Horn
|
f6581f5b55 |
ptrace: restore smp_rmb() in __ptrace_may_access()
Restore the read memory barrier in __ptrace_may_access() that was deleted
a couple years ago. Also add comments on this barrier and the one it pairs
with to explain why they're there (as far as I understand).
Fixes:
|
||
|
Tejun Heo
|
c596687a00 |
cgroup: Fix css_task_iter_advance_css_set() cset skip condition
While adding handling for dying task group leaders |
||
|
Jens Axboe
|
cf8929885d |
cgroup/bfq: revert bfq.weight symlink change
There's some discussion on how to do this the best, and Tejun prefers that BFQ just create the file itself instead of having cgroups support a symlink feature. Hence revert commit |
||
|
Linus Torvalds
|
9331b6740f |
SPDX update for 5.2-rc4
Another round of SPDX header file fixes for 5.2-rc4 These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being added, based on the text in the files. We are slowly chipping away at the 700+ different ways people tried to write the license text. All of these were reviewed on the spdx mailing list by a number of different people. We now have over 60% of the kernel files covered with SPDX tags: $ ./scripts/spdxcheck.py -v 2>&1 | grep Files Files checked: 64533 Files with SPDX: 40392 Files with errors: 0 I think the majority of the "easy" fixups are now done, it's now the start of the longer-tail of crazy variants to wade through. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXPuGTg8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+ykBvQCg2SG+HmDH+tlwKLT/q7jZcLMPQigAoMpt9Uuy sxVEiFZo8ZU9v1IoRb1I =qU++ -----END PGP SIGNATURE----- Merge tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull yet more SPDX updates from Greg KH: "Another round of SPDX header file fixes for 5.2-rc4 These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being added, based on the text in the files. We are slowly chipping away at the 700+ different ways people tried to write the license text. All of these were reviewed on the spdx mailing list by a number of different people. We now have over 60% of the kernel files covered with SPDX tags: $ ./scripts/spdxcheck.py -v 2>&1 | grep Files Files checked: 64533 Files with SPDX: 40392 Files with errors: 0 I think the majority of the "easy" fixups are now done, it's now the start of the longer-tail of crazy variants to wade through" * tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (159 commits) treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 450 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 449 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 448 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 446 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 445 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 444 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 443 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 442 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 436 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 435 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 434 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 433 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 432 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 431 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 430 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 429 ... |
||
|
Linus Torvalds
|
1ce2c85137 |
Char/Misc driver fixes for 5.2-rc4
Here are some small char and misc driver fixes for 5.2-rc4 to resolve a
number of reported issues.
The most "notable" one here is the kernel headers in proc^Wsysfs fixes.
Those changes move the header file info into sysfs and fixes the build
issues that you reported.
Other than that, a bunch of small habanalabs driver fixes, some fpga
driver fixes, and a few other tiny driver fixes.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
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aC5jb20ACgkQMUfUDdst+yma0QCfVPa7r1rHqljz1UgvjKJTzVg8g9wAn1W1mddx
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=0LJD
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Merge tag 'char-misc-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
"Here are some small char and misc driver fixes for 5.2-rc4 to resolve
a number of reported issues.
The most "notable" one here is the kernel headers in proc^Wsysfs
fixes. Those changes move the header file info into sysfs and fixes
the build issues that you reported.
Other than that, a bunch of small habanalabs driver fixes, some fpga
driver fixes, and a few other tiny driver fixes.
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
habanalabs: Read upper bits of trace buffer from RWPHI
habanalabs: Fix virtual address access via debugfs for 2MB pages
fpga: zynqmp-fpga: Correctly handle error pointer
habanalabs: fix bug in checking huge page optimization
habanalabs: Avoid using a non-initialized MMU cache mutex
habanalabs: fix debugfs code
uapi/habanalabs: add opcode for enable/disable device debug mode
habanalabs: halt debug engines on user process close
test_firmware: Use correct snprintf() limit
genwqe: Prevent an integer overflow in the ioctl
parport: Fix mem leak in parport_register_dev_model
fpga: dfl: expand minor range when registering chrdev region
fpga: dfl: Add lockdep classes for pdata->lock
fpga: dfl: afu: Pass the correct device to dma_mapping_error()
fpga: stratix10-soc: fix use-after-free on s10_init()
w1: ds2408: Fix typo after
|
||
|
Linus Torvalds
|
8d72e5bd86 |
for-linus-20190608
-----BEGIN PGP SIGNATURE----- iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAlz7bn4QHGF4Ym9lQGtl cm5lbC5kawAKCRD301j7KXHgpiYlEADG5BaOEqmhRlwFB5slR8b4aOcrQQzjKclZ cgPxOCnINPKRWarR1LSjkCotMZDSZtnsOflbkdKorWebPVqFnmRo8EzK/cPCHhbF w3y/xwMZNU0KWz3KzSOegMgb7cJIj5ryN/4xmTg/4kYWVwMWyuEPaqF83NtGnujR TQmecOjk93IoaOl+YRqYnxqvztqHyRRQdzn/qazkblg5JM3WfrICqDSGdKNRoHzE oOLqVRkLDUO9JWnpqA6n3ZNcksSe80vLbt/syWLqt/XmJJzHJQAjxh8ikVR9cX7R LLyFg/s5cuDVhlZPtIfVyYoGvxenaLMB839UOwt5/PDw4wSLMSnVpw49VM4pz8WJ GMYXBsSzZgpKztf8hzax+3SOX7B5FaV7GV/Hqryt2PxxDJr521Njj29RQz0lwYEe R38zn9VjKABofiC1kGDUYrZ7LVsvcT/dKcZsyIICpzfkKE1OHAWAqgyOHXp+V8uc b4Z4dQONuXL///DcrT7FiZjyq4P3an4wmEuMqEsvH6XO6zo6ndCkw4OXxOzzihXI SYDmKQs92MkTuNxJJFBnEGrfKTOIy/MJDpzrqdFIy/JM6DOtG4pKahIhqD1dwWmw 7a6MZ5AZWZpZ7P7+uQbtl56aC5vby974wax5pfcf061ICNFztgV1ws6wjVnsskRF fPnBMPeYVQ== =vG32 -----END PGP SIGNATURE----- Merge tag 'for-linus-20190608' of git://git.kernel.dk/linux-block Pull block fixes from Jens Axboe: - Allow symlink from the bfq.weight cgroup parameter to the general weight (Angelo) - Damien is new skd maintainer (Bart) - NVMe pull request from Sagi, with a few small fixes. - Ensure we set DMA segment size properly, dma-debug is now tripping on these (Christoph) - Remove useless debugfs_create() return check (Greg) - Remove redundant unlikely() check on IS_ERR() (Kefeng) - Fixup request freeing on exit (Ming) * tag 'for-linus-20190608' of git://git.kernel.dk/linux-block: block, bfq: add weight symlink to the bfq.weight cgroup parameter cgroup: let a symlink too be created with a cftype file block: free sched's request pool in blk_cleanup_queue nvme-rdma: use dynamic dma mapping per command nvme: Fix u32 overflow in the number of namespace list calculation mmc: also set max_segment_size in the device mtip32xx: also set max_segment_size in the device rsxx: don't call dma_set_max_seg_size nvme-pci: don't limit DMA segement size block: Drop unlikely before IS_ERR(_OR_NULL) block: aoe: no need to check return value of debugfs_create functions nvmet: fix data_len to 0 for bdev-backed write_zeroes MAINTAINERS: Hand over skd maintainership nvme-tcp: fix queue mapping when queue count is limited nvme-rdma: fix queue mapping when queue count is limited |
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Linus Torvalds
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a373ec23ab |
Power management fixes for 5.2-rc4
- Fix a crash that occurs when a kernel with 'nosmt' in the command
line is used to resume the system from hibernation (as the "restore"
kernel), because memory mapping differences between the restore and
image kernels cause SMT siblings to be woken up from idle states
and subsequently they try to fetch instructions from incorrect
memory locations (Jiri Kosina).
- Cause the new Performance and Energy Bias Hint (EPB) code to be
built only if CONFIG_PM is set, because that code is not really
necessary otherwise (Rafael Wysocki).
- Add kerneldoc comments to documents some helper functions related
to system-wide suspend to avoid possible confusion regarding their
purpose (Rafael Wysocki).
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Merge tag 'pm-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These fix a crash during resume from hibernation introduced during the
4.19 cycle, cause the new Performance and Energy Bias Hint (EPB) code
to be built only if CONFIG_PM is set and add a few missing kerneldoc
comments.
Specifics:
- Fix a crash that occurs when a kernel with 'nosmt' in the command
line is used to resume the system from hibernation (as the
"restore" kernel), because memory mapping differences between the
restore and image kernels cause SMT siblings to be woken up from
idle states and subsequently they try to fetch instructions from
incorrect memory locations (Jiri Kosina).
- Cause the new Performance and Energy Bias Hint (EPB) code to be
built only if CONFIG_PM is set, because that code is not really
necessary otherwise (Rafael Wysocki).
- Add kerneldoc comments to documents some helper functions related
to system-wide suspend to avoid possible confusion regarding their
purpose (Rafael Wysocki)"
* tag 'pm-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
x86/power: Fix 'nosmt' vs hibernation triple fault during resume
PM: sleep: Add kerneldoc comments to some functions
x86: intel_epb: Do not build when CONFIG_PM is unset
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Rafael J. Wysocki
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a964d23c94 |
Merge branch 'pm-x86'
* pm-x86: x86/power: Fix 'nosmt' vs hibernation triple fault during resume x86: intel_epb: Do not build when CONFIG_PM is unset |
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Angelo Ruocco
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54b7b868e8 |
cgroup: let a symlink too be created with a cftype file
This commit enables a cftype to have a symlink (of any name) that points to the file associated with the cftype. Signed-off-by: Angelo Ruocco <angeloruocco90@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
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Tejun Heo
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cee0c33c54 |
cgroup: css_task_iter_skip()'d iterators must be advanced before accessed
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Thomas Gleixner
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b886d83c5b |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |