22 Feb, 2015
1 commit
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Pull locking fixes from Ingo Molnar:
"Two fixes: the paravirt spin_unlock() corruption/crash fix, and an
rtmutex NULL dereference crash fix"* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/spinlocks/paravirt: Fix memory corruption on unlock
locking/rtmutex: Avoid a NULL pointer dereference on deadlock
18 Feb, 2015
1 commit
-
With task_blocks_on_rt_mutex() returning early -EDEADLK we never
add the waiter to the waitqueue. Later, we try to remove it via
remove_waiter() and go boom in rt_mutex_top_waiter() because
rb_entry() gives a NULL pointer.( Tested on v3.18-RT where rtmutex is used for regular mutex and I
tried to get one twice in a row. )Not sure when this started but I guess 397335f004f4 ("rtmutex: Fix
deadlock detector for real") or commit 3d5c9340d194 ("rtmutex:
Handle deadlock detection smarter").Signed-off-by: Sebastian Andrzej Siewior
Acked-by: Peter Zijlstra
Cc: Thomas Gleixner
Cc: # for v3.16 and later kernels
Link: http://lkml.kernel.org/r/1424187823-19600-1-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar
12 Feb, 2015
1 commit
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Pull s390 updates from Martin Schwidefsky:
- The remaining patches for the z13 machine support: kernel build
option for z13, the cache synonym avoidance, SMT support,
compare-and-delay for spinloops and the CES5S crypto adapater.- The ftrace support for function tracing with the gcc hotpatch option.
This touches common code Makefiles, Steven is ok with the changes.- The hypfs file system gets an extension to access diagnose 0x0c data
in user space for performance analysis for Linux running under z/VM.- The iucv hvc console gets wildcard spport for the user id filtering.
- The cacheinfo code is converted to use the generic infrastructure.
- Cleanup and bug fixes.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits)
s390/process: free vx save area when releasing tasks
s390/hypfs: Eliminate hypfs interval
s390/hypfs: Add diagnose 0c support
s390/cacheinfo: don't use smp_processor_id() in preemptible context
s390/zcrypt: fixed domain scanning problem (again)
s390/smp: increase maximum value of NR_CPUS to 512
s390/jump label: use different nop instruction
s390/jump label: add sanity checks
s390/mm: correct missing space when reporting user process faults
s390/dasd: cleanup profiling
s390/dasd: add locking for global_profile access
s390/ftrace: hotpatch support for function tracing
ftrace: let notrace function attribute disable hotpatching if necessary
ftrace: allow architectures to specify ftrace compile options
s390: reintroduce diag 44 calls for cpu_relax()
s390/zcrypt: Add support for new crypto express (CEX5S) adapter.
s390/zcrypt: Number of supported ap domains is not retrievable.
s390/spinlock: add compare-and-delay to lock wait loops
s390/tape: remove redundant if statement
s390/hvc_iucv: add simple wildcard matches to the iucv allow filter
...
11 Feb, 2015
1 commit
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Pull networking updates from David Miller:
1) More iov_iter conversion work from Al Viro.
[ The "crypto: switch af_alg_make_sg() to iov_iter" commit was
wrong, and this pull actually adds an extra commit on top of the
branch I'm pulling to fix that up, so that the pre-merge state is
ok. - Linus ]2) Various optimizations to the ipv4 forwarding information base trie
lookup implementation. From Alexander Duyck.3) Remove sock_iocb altogether, from CHristoph Hellwig.
4) Allow congestion control algorithm selection via routing metrics.
From Daniel Borkmann.5) Make ipv4 uncached route list per-cpu, from Eric Dumazet.
6) Handle rfs hash collisions more gracefully, also from Eric Dumazet.
7) Add xmit_more support to r8169, e1000, and e1000e drivers. From
Florian Westphal.8) Transparent Ethernet Bridging support for GRO, from Jesse Gross.
9) Add BPF packet actions to packet scheduler, from Jiri Pirko.
10) Add support for uniqu flow IDs to openvswitch, from Joe Stringer.
11) New NetCP ethernet driver, from Muralidharan Karicheri and Wingman
Kwok.12) More sanely handle out-of-window dupacks, which can result in
serious ACK storms. From Neal Cardwell.13) Various rhashtable bug fixes and enhancements, from Herbert Xu,
Patrick McHardy, and Thomas Graf.14) Support xmit_more in be2net, from Sathya Perla.
15) Group Policy extensions for vxlan, from Thomas Graf.
16) Remove Checksum Offload support for vxlan, from Tom Herbert.
17) Like ipv4, support lockless transmit over ipv6 UDP sockets. From
Vlad Yasevich.* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1494+1 commits)
crypto: fix af_alg_make_sg() conversion to iov_iter
ipv4: Namespecify TCP PMTU mechanism
i40e: Fix for stats init function call in Rx setup
tcp: don't include Fast Open option in SYN-ACK on pure SYN-data
openvswitch: Only set TUNNEL_VXLAN_OPT if VXLAN-GBP metadata is set
ipv6: Make __ipv6_select_ident static
ipv6: Fix fragment id assignment on LE arches.
bridge: Fix inability to add non-vlan fdb entry
net: Mellanox: Delete unnecessary checks before the function call "vunmap"
cxgb4: Add support in cxgb4 to get expansion rom version via ethtool
ethtool: rename reserved1 memeber in ethtool_drvinfo for expansion ROM version
net: dsa: Remove redundant phy_attach()
IB/mlx4: Reset flow support for IB kernel ULPs
IB/mlx4: Always use the correct port for mirrored multicast attachments
net/bonding: Fix potential bad memory access during bonding events
tipc: remove tipc_snprintf
tipc: nl compat add noop and remove legacy nl framework
tipc: convert legacy nl stats show to nl compat
tipc: convert legacy nl net id get to nl compat
tipc: convert legacy nl net id set to nl compat
...
10 Feb, 2015
1 commit
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Pull scheduler updates from Ingo Molnar:
"The main scheduler changes in this cycle were:- various sched/deadline fixes and enhancements
- rescheduling latency fixes/cleanups
- rework the rq->clock code to be more consistent and more robust.
- minor micro-optimizations
- ->avg.decay_count fixes
- add a stack overflow check to might_sleep()
- idle-poll handler fix, possibly resulting in power savings
- misc smaller updates and fixes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/Documentation: Remove unneeded word
sched/wait: Introduce wait_on_bit_timeout()
sched: Pull resched loop to __schedule() callers
sched/deadline: Remove cpu_active_mask from cpudl_find()
sched: Fix hrtick_start() on UP
sched/deadline: Avoid pointless __setscheduler()
sched/deadline: Fix stale yield state
sched/deadline: Fix hrtick for a non-leftmost task
sched/deadline: Modify cpudl::free_cpus to reflect rd->online
sched/idle: Add missing checks to the exit condition of cpu_idle_poll()
sched: Fix missing preemption opportunity
sched/rt: Reduce rq lock contention by eliminating locking of non-feasible target
sched/debug: Print rq->clock_task
sched/core: Rework rq->clock update skips
sched/core: Validate rq_clock*() serialization
sched/core: Remove check of p->sched_class
sched/fair: Fix sched_entity::avg::decay_count initialization
sched/debug: Fix potential call to __ffs(0) in sched_show_task()
sched/debug: Check for stack overflow in ___might_sleep()
sched/fair: Fix the dealing with decay_count in __synchronize_entity_decay()
04 Feb, 2015
4 commits
-
We explicitly mark the task running after returning from
a __rt_mutex_slowlock() call, which does the actual sleeping
via wait-wake-trylocking. As such, this patch does two things:(1) refactors the code so that setting current to TASK_RUNNING
is done by __rt_mutex_slowlock(), and not by the callers. The
downside to this is that it becomes a bit unclear when at what
point we block. As such I've added a comment that the task
blocks when calling __rt_mutex_slowlock() so readers can figure
out when it is running again.(2) relaxes setting current's state through __set_current_state(),
instead of it's more expensive barrier alternative. There was no
need for the implied barrier as we're obviously not planning on
blocking.Signed-off-by: Davidlohr Bueso
Signed-off-by: Peter Zijlstra (Intel)
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1422857784.18096.1.camel@stgolabs.net
Signed-off-by: Ingo Molnar -
Call __set_task_state() instead of assigning the new state
directly. These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP
environments, keeping track of who last changed the state.Signed-off-by: Davidlohr Bueso
Signed-off-by: Peter Zijlstra (Intel)
Cc: "Paul E. McKenney"
Cc: Jason Low
Cc: Michel Lespinasse
Cc: Tim Chen
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1422257769-14083-2-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar -
By the time we wake up and get the lock after being asleep
in the slowpath, we better be running. As good practice,
be explicit about this and avoid any mischief.Signed-off-by: Davidlohr Bueso
Signed-off-by: Peter Zijlstra (Intel)
Cc: "Paul E. McKenney"
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1421717961.4903.11.camel@stgolabs.net
Signed-off-by: Ingo Molnar -
The second 'mutex' shouldn't be there, it can't be about the mutex,
as the mutex can't be freed, but unlocked, the memory where the
mutex resides however, can be freed.Signed-off-by: Sharon Dvir
Signed-off-by: Peter Zijlstra (Intel)
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1422827252-31363-1-git-send-email-sharon.dvir1@mail.huji.ac.il
Signed-off-by: Ingo Molnar
29 Jan, 2015
1 commit
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If the kernel is compiled with function tracer support the -pg compile option
is passed to gcc to generate extra code into the prologue of each function.This patch replaces the "open-coded" -pg compile flag with a CC_FLAGS_FTRACE
makefile variable which architectures can override if a different option
should be used for code generation.Acked-by: Steven Rostedt
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
15 Jan, 2015
1 commit
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Conflicts:
drivers/net/xen-netfront.cMinor overlapping changes in xen-netfront.c, mostly to do
with some buffer management changes alongside the split
of stats into TX and RX.Signed-off-by: David S. Miller
14 Jan, 2015
5 commits
-
Both mutexes and rwsems took a performance hit when we switched
over from the original mcs code to the cancelable variant (osq).
The reason being the use of smp_load_acquire() when polling for
node->locked. This is not needed as reordering is not an issue,
as such, relax the barrier semantics. Paul describes the scenario
nicely: https://lkml.org/lkml/2013/11/19/405- If we start polling before the insertion is complete, all that
happens is that the first few polls have no chance of seeing a lock
grant.- Ordering the polling against the initialization -- the above
xchg() is already doing that for us.The smp_load_acquire() when unqueuing make sense. In addition,
we don't need to worry about leaking the critical region as
osq is only used internally.This impacts both regular and large levels of concurrency,
ie on a 40 core system with a disk intensive workload:disk-1 804.83 ( 0.00%) 828.16 ( 2.90%)
disk-61 8063.45 ( 0.00%) 18181.82 (125.48%)
disk-121 7187.41 ( 0.00%) 20119.17 (179.92%)
disk-181 6933.32 ( 0.00%) 20509.91 (195.82%)
disk-241 6850.81 ( 0.00%) 20397.80 (197.74%)
disk-301 6815.22 ( 0.00%) 20287.58 (197.68%)
disk-361 7080.40 ( 0.00%) 20205.22 (185.37%)
disk-421 7076.13 ( 0.00%) 19957.33 (182.04%)
disk-481 7083.25 ( 0.00%) 19784.06 (179.31%)
disk-541 7038.39 ( 0.00%) 19610.92 (178.63%)
disk-601 7072.04 ( 0.00%) 19464.53 (175.23%)
disk-661 7010.97 ( 0.00%) 19348.23 (175.97%)
disk-721 7069.44 ( 0.00%) 19255.33 (172.37%)
disk-781 7007.58 ( 0.00%) 19103.14 (172.61%)
disk-841 6981.18 ( 0.00%) 18964.22 (171.65%)
disk-901 6968.47 ( 0.00%) 18826.72 (170.17%)
disk-961 6964.61 ( 0.00%) 18708.02 (168.62%)Signed-off-by: Davidlohr Bueso
Signed-off-by: Peter Zijlstra (Intel)
Cc: "Paul E. McKenney"
Cc: Thomas Gleixner
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1420573509-24774-7-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar -
We have two flavors of the MCS spinlock: standard and cancelable (OSQ).
While each one is independent of the other, we currently mix and match
them. This patch:- Moves the OSQ code out of mcs_spinlock.h (which only deals with the traditional
version) into include/linux/osq_lock.h. No unnecessary code is added to the
more global header file, anything locks that make use of OSQ must include
it anyway.- Renames mcs_spinlock.c to osq_lock.c. This file only contains osq code.
- Introduces a CONFIG_LOCK_SPIN_ON_OWNER in order to only build osq_lock
if there is support for it.Signed-off-by: Davidlohr Bueso
Signed-off-by: Peter Zijlstra (Intel)
Cc: Thomas Gleixner
Cc: "Paul E. McKenney"
Cc: Jason Low
Cc: Linus Torvalds
Cc: Mikulas Patocka
Cc: Waiman Long
Link: http://lkml.kernel.org/r/1420573509-24774-5-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar -
... which is equivalent to the fastpath counter part.
This mainly allows getting some WW specific code out
of generic mutex paths.Signed-off-by: Davidlohr Bueso
Signed-off-by: Peter Zijlstra (Intel)
Cc: "Paul E. McKenney"
Cc: Thomas Gleixner
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1420573509-24774-4-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar -
It serves much better if the comments are right before the osq_lock() call.
Also delete a useless comment.Signed-off-by: Davidlohr Bueso
Signed-off-by: Peter Zijlstra (Intel)
Cc: "Paul E. McKenney"
Cc: Thomas Gleixner
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1420573509-24774-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar -
Mark it so by renaming __mutex_lock_check_stamp().
Signed-off-by: Davidlohr Bueso
Signed-off-by: Peter Zijlstra (Intel)
Cc: "Paul E. McKenney"
Cc: Thomas Gleixner
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1420573509-24774-2-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar
09 Jan, 2015
1 commit
-
Currently if DEBUG_MUTEXES is enabled, the mutex->owner field is only
cleared iff debug_locks is active. This exposes a race to other users of
the field where the mutex->owner may be still set to a stale value,
potentially upsetting mutex_spin_on_owner() among others.References: https://bugs.freedesktop.org/show_bug.cgi?id=87955
Signed-off-by: Chris Wilson
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Davidlohr Bueso
Cc: Daniel Vetter
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1420540175-30204-1-git-send-email-chris@chris-wilson.co.uk
Signed-off-by: Ingo Molnar
04 Jan, 2015
1 commit
-
Signed-off-by: Thomas Graf
Signed-off-by: David S. Miller
28 Oct, 2014
1 commit
-
We're going to make might_sleep() test for TASK_RUNNING, because
blocking without TASK_RUNNING will destroy the task state by setting
it to TASK_RUNNING.There are a few occasions where its 'valid' to call blocking
primitives (and mutex_lock in particular) and not have TASK_RUNNING,
typically such cases are right before we set TASK_RUNNING anyhow.Robustify the code by not assuming this; this has the beneficial side
effect of allowing optional code emission for fixing the above
might_sleep() false positives.Signed-off-by: Peter Zijlstra (Intel)
Cc: tglx@linutronix.de
Cc: ilya.dryomov@inktank.com
Cc: umgwanakikbuti@gmail.com
Cc: Oleg Nesterov
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/20140924082241.988560063@infradead.org
Signed-off-by: Ingo Molnar
13 Oct, 2014
1 commit
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Pull core locking updates from Ingo Molnar:
"The main updates in this cycle were:- mutex MCS refactoring finishing touches: improve comments, refactor
and clean up code, reduce debug data structure footprint, etc.- qrwlock finishing touches: remove old code, self-test updates.
- small rwsem optimization
- various smaller fixes/cleanups"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/lockdep: Revert qrwlock recusive stuff
locking/rwsem: Avoid double checking before try acquiring write lock
locking/rwsem: Move EXPORT_SYMBOL() lines to follow function definition
locking/rwlock, x86: Delete unused asm/rwlock.h and rwlock.S
locking/rwlock, x86: Clean up asm/spinlock*.h to remove old rwlock code
locking/semaphore: Resolve some shadow warnings
locking/selftest: Support queued rwlock
locking/lockdep: Restrict the use of recursive read_lock() with qrwlock
locking/spinlocks: Always evaluate the second argument of spin_lock_nested()
locking/Documentation: Update locking/mutex-design.txt disadvantages
locking/Documentation: Move locking related docs into Documentation/locking/
locking/mutexes: Use MUTEX_SPIN_ON_OWNER when appropriate
locking/mutexes: Refactor optimistic spinning code
locking/mcs: Remove obsolete comment
locking/mutexes: Document quick lock release when unlocking
locking/mutexes: Standardize arguments in lock/unlock slowpaths
locking: Remove deprecated smp_mb__() barriers
03 Oct, 2014
2 commits
-
Commit f0bab73cb539 ("locking/lockdep: Restrict the use of recursive
read_lock() with qrwlock") changed lockdep to try and conform to the
qrwlock semantics which differ from the traditional rwlock semantics.In particular qrwlock is fair outside of interrupt context, but in
interrupt context readers will ignore all fairness.The problem modeling this is that read and write side have different
lock state (interrupts) semantics but we only have a single
representation of these. Therefore lockdep will get confused, thinking
the lock can cause interrupt lock inversions.So revert it for now; the old rwlock semantics were already imperfectly
modeled and the qrwlock extra won't fit either.If we want to properly fix this, I think we need to resurrect the work
by Gautham did a few years ago that split the read and write state of
locks:http://lwn.net/Articles/332801/
FWIW the locking selftest that would've failed (and was reported by
Borislav earlier) is something like:RL(X1); /* IRQ-ON */
LOCK(A);
UNLOCK(A);
RU(X1);IRQ_ENTER();
RL(X1); /* IN-IRQ */
RU(X1);
IRQ_EXIT();At which point it would report that because A is an IRQ-unsafe lock we
can suffer the following inversion:CPU0 CPU1
lock(A)
lock(X1)
lock(A)
lock(X1)And this is 'wrong' because X1 can recurse (assuming the above lock are
in fact read-lock) but lockdep doesn't know about this.Signed-off-by: Peter Zijlstra (Intel)
Cc: Waiman Long
Cc: ego@linux.vnet.ibm.com
Cc: bp@alien8.de
Cc: Linus Torvalds
Cc: Paul E. McKenney
Link: http://lkml.kernel.org/r/20140930132600.GA7444@worktop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar -
Commit 9b0fc9c09f1b ("rwsem: skip initial trylock in rwsem_down_write_failed")
checks for if there are known active lockers in order to avoid write trylocking
using expensive cmpxchg() when it likely wouldn't get the lock.However, a subsequent patch was added such that we directly
check for sem->count == RWSEM_WAITING_BIAS right before trying
that cmpxchg().Thus, commit 9b0fc9c09f1b now just adds overhead.
This patch modifies it so that we only do a check for if
count == RWSEM_WAITING_BIAS.Also, add a comment on why we do an "extra check" of count
before the cmpxchg().Signed-off-by: Jason Low
Acked-by: Davidlohr Bueso
Signed-off-by: Peter Zijlstra (Intel)
Cc: Aswin Chandramouleeswaran
Cc: Chegu Vinod
Cc: Peter Hurley
Cc: Tim Chen
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1410913017.2447.22.camel@j-VirtualBox
Signed-off-by: Ingo Molnar
30 Sep, 2014
4 commits
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Remove some unnecessary ones and explicitly include rwsem.h
Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
... trigger an error if so.
Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
Its quite easy to get mixed up with the names -- 'torture_spinlock_irq'
is not actually a valid spinlock name.Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
Add a "rw_lock" torture test to stress kernel rwlocks and their irq
variant. Reader critical regions are 5x longer than writers. As such
a similar ratio of lock acquisitions is seen in the statistics. In the
case of massive contention, both hold the lock for 1/10 of a second.Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney
17 Sep, 2014
8 commits
-
The amount of global variables is getting pretty ugly. Group variables
related to the execution (ie: not parameters) in a new context structure.Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
We can easily do so with our new reader lock support. Just an arbitrary
design default: readers have higher (5x) critical region latencies than
writers: 50 ms and 10 ms, respectively.Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
Most of it is based on what we already have for writers. This allows
readers to be very independent (and thus configurable), enabling
future module parameters to control things such as rw distribution.
Furthermore, readers have their own delaying function, allowing us
to test different rw critical region latencies, and stress locking
internals. Similarly, statistics, for now will only serve for the
number of lock acquisitions -- as opposed to writers, readers have
no failure detection.In addition, introduce a new nreaders_stress module parameter. The
default number of readers will be the same number of writers threads.
Writer threads are interleaved with readers. Documentation is updated,
respectively.Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
When performing module cleanups by calling torture_cleanup() the
'torture_type' string in nullified However, callers are not necessarily
done, and might still need to reference the variable. This impacts
both rcutorture and locktorture, causing printing things like:[ 94.226618] (null)-torture: Stopping lock_torture_writer task
[ 94.226624] (null)-torture: Stopping lock_torture_stats taskThus delay this operation until the very end of the cleanup process.
The consequence (which shouldn't matter for this kid of program) is,
of course, that we delay the window between rmmod and modprobing,
for instance in module_torture_begin().Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
The statistics structure can serve well for both reader and writer
locks, thus simply rename some fields that mention 'write' and leave
the declaration of lwsa.Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
Regular locks are very different than locks with debugging. For instance
for mutexes, debugging forces to only take the slowpaths. As such, the
locktorture module should take this into account when printing related
information -- specifically when printing user passed parameters, it seems
the right place for such info.Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
Add a "mutex_lock" torture test. The main difference with the already
existing spinlock tests is that the latency of the critical region
is much larger. We randomly delay for (arbitrarily) either 500 ms or,
otherwise, 25 ms. While this can considerably reduce the amount of
writes compared to non blocking locks, if run long enough it can have
the same torturous effect. Furthermore it is more representative of
mutex hold times and can stress better things like thrashing.Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney -
... to just 'torture_runnable'. It follows other variable naming
and is shorter.Signed-off-by: Davidlohr Bueso
Signed-off-by: Paul E. McKenney
16 Sep, 2014
1 commit
-
rw-semaphore is the only type of lock doing this ugliness of
exporting at the end of the file.Signed-off-by: Davidlohr Bueso
Cc: dave@stgolabs.net
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1410500066-5909-1-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar
04 Sep, 2014
1 commit
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Resolve some shadow warnings resulting from using the name
jiffies, which is a well-known global. This is not a problem
of course, but it could be a trap for someone copying and
pasting code, and it just makes W=2 a little cleaner.Signed-off-by: Mark Rustad
Signed-off-by: Jeff Kirsher
Acked-by: Peter Zijlstra
Cc: Linus Torvalds
Cc: Andrew Morton
Cc: Thomas Gleixner
Cc: Paul E. McKenney
Link: http://lkml.kernel.org/r/1409739444-13635-1-git-send-email-jeffrey.t.kirsher@intel.com
Signed-off-by: Ingo Molnar
13 Aug, 2014
4 commits
-
Unlike the original unfair rwlock implementation, queued rwlock
will grant lock according to the chronological sequence of the lock
requests except when the lock requester is in the interrupt context.
Consequently, recursive read_lock calls will now hang the process if
there is a write_lock call somewhere in between the read_lock calls.This patch updates the lockdep implementation to look for recursive
read_lock calls. A new read state (3) is used to mark those read_lock
call that cannot be recursively called except in the interrupt
context. The new read state does exhaust the 2 bits available in
held_lock:read bit field. The addition of any new read state in the
future may require a redesign of how all those bits are squeezed
together in the held_lock structure.Signed-off-by: Waiman Long
Signed-off-by: Peter Zijlstra
Cc: Maarten Lankhorst
Cc: Rik van Riel
Cc: Scott J Norton
Cc: Fengguang Wu
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1407345722-61615-2-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar -
Specifically:
Documentation/locking/lockdep-design.txt
Documentation/locking/lockstat.txt
Documentation/locking/mutex-design.txt
Documentation/locking/rt-mutex-design.txt
Documentation/locking/rt-mutex.txt
Documentation/locking/spinlocks.txt
Documentation/locking/ww-mutex-design.txtSigned-off-by: Davidlohr Bueso
Acked-by: Randy Dunlap
Signed-off-by: Peter Zijlstra
Cc: jason.low2@hp.com
Cc: aswin@hp.com
Cc: Alexei Starovoitov
Cc: Al Viro
Cc: Andrew Morton
Cc: Chris Mason
Cc: Dan Streetman
Cc: David Airlie
Cc: Davidlohr Bueso
Cc: David S. Miller
Cc: Greg Kroah-Hartman
Cc: Heiko Carstens
Cc: Jason Low
Cc: Josef Bacik
Cc: Kees Cook
Cc: Linus Torvalds
Cc: Lubomir Rintel
Cc: Masanari Iida
Cc: Paul E. McKenney
Cc: Randy Dunlap
Cc: Tim Chen
Cc: Vineet Gupta
Cc: fengguang.wu@intel.com
Link: http://lkml.kernel.org/r/1406752916-3341-6-git-send-email-davidlohr@hp.com
Signed-off-by: Ingo Molnar -
4badad35 ("locking/mutex: Disable optimistic spinning on some
architectures") added a ARCH_SUPPORTS_ATOMIC_RMW flag to
disable the mutex optimistic feature on specific archs.Because CONFIG_MUTEX_SPIN_ON_OWNER only depended on DEBUG and
SMP, it was ok to have the ->owner field conditional a bit
flexible. However by adding a new variable to the matter,
we can waste space with the unused field, ie: CONFIG_SMP &&
(!CONFIG_MUTEX_SPIN_ON_OWNER && !CONFIG_DEBUG_MUTEX).Signed-off-by: Davidlohr Bueso
Acked-by: Jason Low
Signed-off-by: Peter Zijlstra
Cc: aswin@hp.com
Cc: Davidlohr Bueso
Cc: Heiko Carstens
Cc: Jason Low
Cc: Linus Torvalds
Cc: Paul E. McKenney
Cc: Tim Chen
Link: http://lkml.kernel.org/r/1406752916-3341-5-git-send-email-davidlohr@hp.com
Signed-off-by: Ingo Molnar -
When we fail to acquire the mutex in the fastpath, we end up calling
__mutex_lock_common(). A *lot* goes on in this function. Move out the
optimistic spinning code into mutex_optimistic_spin() and simplify
the former a bit. Furthermore, this is similar to what we have in
rwsems. No logical changes.Signed-off-by: Davidlohr Bueso
Acked-by: Jason Low
Signed-off-by: Peter Zijlstra
Cc: aswin@hp.com
Cc: mingo@kernel.org
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/1406752916-3341-4-git-send-email-davidlohr@hp.com
Signed-off-by: Ingo Molnar
