Dave Hansen [Thu, 18 Sep 2014 19:33:34 +0000 (12:33 -0700)]
x86, sched: Add new topology for multi-NUMA-node CPUs
I'm getting the spew below when booting with Haswell (Xeon
E5-2699 v3) CPUs and the "Cluster-on-Die" (CoD) feature enabled
in the BIOS. It seems similar to the issue that some folks from
AMD ran in to on their systems and addressed in this commit:
161270fc1f9d ("x86/smp: Fix topology checks on AMD MCM CPUs")
Both these Intel and AMD systems break an assumption which is
being enforced by topology_sane(): a socket may not contain more
than one NUMA node.
AMD special-cased their system by looking for a cpuid flag. The
Intel mode is dependent on BIOS options and I do not know of a
way which it is enumerated other than the tables being parsed
during the CPU bringup process. In other words, we have to trust
the ACPI tables <shudder>.
This detects the situation where a NUMA node occurs at a place in
the middle of the "CPU" sched domains. It replaces the default
topology with one that relies on the NUMA information from the
firmware (SRAT table) for all levels of sched domains above the
hyperthreads.
This also fixes a sysfs bug. We used to freak out when we saw
the "mc" group cross a node boundary, so we stopped building the
MC group. MC gets exported as the 'core_siblings_list' in
/sys/devices/system/cpu/cpu*/topology/ and this caused CPUs with
the same 'physical_package_id' to not be listed together in
'core_siblings_list'. This violates a statement from
Documentation/ABI/testing/sysfs-devices-system-cpu:
core_siblings: internal kernel map of cpu#'s hardware threads
within the same physical_package_id.
core_siblings_list: human-readable list of the logical CPU
numbers within the same physical_package_id as cpu#.
The sysfs effects here cause an issue with the hwloc tool where
it gets confused and thinks there are more sockets than are
physically present.
Kirill found that there's a subtle race in the
__ARCH_WANT_UNLOCKED_CTXSW code, and instead of fixing it, remove the
entire exception because neither arch that uses it seems to actually
still require it.
read_lock_irqsave(tasklist_lock) in print_rq() looks strange. We do
not need to disable irqs, and they are already disabled by the caller.
And afaics this lock buys nothing, we can rely on rcu_read_lock().
In this case it makes sense to also move rcu_read_lock/unlock from
the caller to print_rq().
Nicolas Pitre [Thu, 4 Sep 2014 15:32:10 +0000 (11:32 -0400)]
sched/fair: Leverage the idle state info when choosing the "idlest" cpu
The code in find_idlest_cpu() looks for the CPU with the smallest load.
However, if multiple CPUs are idle, the first idle CPU is selected
irrespective of the depth of its idle state.
Among the idle CPUs we should pick the one with with the shallowest idle
state, or the latest to have gone idle if all idle CPUs are in the same
state. The later applies even when cpuidle is configured out.
This patch doesn't cover the following issues:
- The idle exit latency of a CPU might be larger than the time needed
to migrate the waking task to an already running CPU with sufficient
capacity, and therefore performance would benefit from task packing
in such case (in most cases task packing is about power saving).
- Some idle states have a non negligible and non abortable entry latency
which needs to run to completion before the exit latency can start.
A concurrent patch series is making this info available to the cpuidle
core. Once available, the entry latency with the idle timestamp could
determine when the exit latency may be effective.
Those issues will be handled in due course. In the mean time, what
is implemented here should improve things already compared to the current
state of affairs.
Based on an initial patch from Daniel Lezcano.
Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-pm@vger.kernel.org Cc: linaro-kernel@lists.linaro.org Link: http://lkml.kernel.org/n/tip-@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Lezcano [Thu, 4 Sep 2014 15:32:09 +0000 (11:32 -0400)]
sched: Let the scheduler see CPU idle states
When the cpu enters idle, it stores the cpuidle state pointer in its
struct rq instance which in turn could be used to make a better decision
when balancing tasks.
As soon as the cpu exits its idle state, the struct rq reference is
cleared.
There are a couple of situations where the idle state pointer could be changed
while it is being consulted:
1. For x86/acpi with dynamic c-states, when a laptop switches from battery
to AC that could result on removing the deeper idle state. The acpi driver
triggers:
'acpi_processor_cst_has_changed'
'cpuidle_pause_and_lock'
'cpuidle_uninstall_idle_handler'
'kick_all_cpus_sync'.
All cpus will exit their idle state and the pointed object will be set to
NULL.
2. The cpuidle driver is unloaded. Logically that could happen but not
in practice because the drivers are always compiled in and 95% of them are
not coded to unregister themselves. In any case, the unloading code must
call 'cpuidle_unregister_device', that calls 'cpuidle_pause_and_lock'
leading to 'kick_all_cpus_sync' as mentioned above.
A race can happen if we use the pointer and then one of these two scenarios
occurs at the same moment.
In order to be safe, the idle state pointer stored in the rq must be
used inside a rcu_read_lock section where we are protected with the
'rcu_barrier' in the 'cpuidle_uninstall_idle_handler' function. The
idle_get_state() and idle_put_state() accessors should be used to that
effect.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org Cc: linaro-kernel@lists.linaro.org Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Users can perform clustered scheduling using the cpuset facility.
After an exclusive cpuset is created, task migrations happen only
between CPUs belonging to the same cpuset. Inter- cpuset migrations
can only happen when the user requires so, moving a task between
different cpusets. This behaviour is broken in SCHED_DEADLINE, as
currently spurious inter- cpuset migration may happen without user
intervention.
This patch fix the problem (and shuffles the code a bit to improve
clarity).
Juri Lelli [Fri, 19 Sep 2014 09:22:39 +0000 (10:22 +0100)]
sched/deadline: Clear dl_entity params when setscheduling to different class
When a task is using SCHED_DEADLINE and the user setschedules it to a
different class its sched_dl_entity static parameters are not cleaned
up. This causes a bug if the user sets it back to SCHED_DEADLINE with
the same parameters again. The problem resides in the check we
perform at the very beginning of dl_overflow():
if (new_bw == p->dl.dl_bw)
return 0;
This condition is met in the case depicted above, so the function
returns and dl_b->total_bw is not updated (the p->dl.dl_bw is not
added to it). After this, admission control is broken.
This patch fixes the thing, properly clearing static parameters for a
task that ceases to use SCHED_DEADLINE.
Reported-by: Daniele Alessandrelli <daniele.alessandrelli@gmail.com> Reported-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Reported-by: Vincent Legout <vincent@legout.info> Tested-by: Luca Abeni <luca.abeni@unitn.it> Tested-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Tested-by: Vincent Legout <vincent@legout.info> Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Fabio Checconi <fchecconi@gmail.com> Cc: Dario Faggioli <raistlin@linux.it> Cc: Michael Trimarchi <michael@amarulasolutions.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1411118561-26323-2-git-send-email-juri.lelli@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vincent Guittot [Tue, 26 Aug 2014 11:06:50 +0000 (13:06 +0200)]
sched: Test the CPU's capacity in wake_affine()
Currently the task always wakes affine on this_cpu if the latter is idle.
Before waking up the task on this_cpu, we check that this_cpu capacity is not
significantly reduced because of RT tasks or irq activity.
Use case where the number of irq and/or the time spent under irq is important
will take benefit of this because the task that is woken up by irq or softirq
will not use the same CPU than irq (and softirq) but a idle one.
Vincent Guittot [Tue, 26 Aug 2014 11:06:48 +0000 (13:06 +0200)]
ARM: topology: Use the new cpu_capacity interface
Use the new arch_scale_cpu_capacity() scheduler facility in order to reflect
the original capacity of a CPU instead of arch_scale_freq_capacity() which is
more linked to a scaling of the capacity linked to the frequency.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: preeti@linux.vnet.ibm.com Cc: riel@redhat.com Cc: Morten.Rasmussen@arm.com Cc: efault@gmx.de Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: Grant Likely <grant.likely@linaro.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Brown <broonie@linaro.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: devicetree@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1409051215-16788-6-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vincent Guittot [Tue, 26 Aug 2014 11:06:47 +0000 (13:06 +0200)]
sched: Allow all architectures to set 'capacity_orig'
'capacity_orig' is only changed for systems with an SMT sched_domain level in order
to reflect the lower capacity of CPUs. Heterogenous systems also have to reflect an
original capacity that is different from the default value.
Create a more generic function arch_scale_cpu_capacity that can be also used by
non SMT platforms to set capacity_orig.
The __weak implementation of arch_scale_cpu_capacity() is the previous SMT variant,
in order to keep backward compatibility with the use of capacity_orig.
arch_scale_smt_capacity() and default_scale_smt_capacity() have been removed as
they were not used elsewhere than in arch_scale_cpu_capacity().
Vincent Guittot [Tue, 26 Aug 2014 11:06:46 +0000 (13:06 +0200)]
sched: Fix avg_load computation
The computation of avg_load and avg_load_per_task should only take into
account the number of CFS tasks. The non-CFS tasks are already taken into
account by decreasing the CPU's capacity and they will be tracked in the
CPU's utilization (group_utilization) of the next patches.
It implies that runnable_load_avg == 0 and nr_running <= 1 in order to match the
condition. This implies that runnable_load_avg == 0 too because of the
condition: this_load <= load.
but if this _load is null, 'balanced' is already set and the test is redundant.
If sync is set, it's not as straight forward as above (especially if cgroup
are involved) but the policy should be similar as we have removed a task that's
going to sleep in order to get a more accurate load and this_load values.
The current conclusion is that these additional condition don't give any benefit
so we can remove them.
Vincent Guittot [Tue, 26 Aug 2014 11:06:44 +0000 (13:06 +0200)]
sched: Fix imbalance flag reset
The imbalance flag can stay set whereas there is no imbalance.
Let assume that we have 3 tasks that run on a dual cores /dual cluster system.
We will have some idle load balance which are triggered during tick.
Unfortunately, the tick is also used to queue background work so we can reach
the situation where short work has been queued on a CPU which already runs a
task. The load balance will detect this imbalance (2 tasks on 1 CPU and an idle
CPU) and will try to pull the waiting task on the idle CPU. The waiting task is
a worker thread that is pinned on a CPU so an imbalance due to pinned task is
detected and the imbalance flag is set.
Then, we will not be able to clear the flag because we have at most 1 task on
each CPU but the imbalance flag will trig to useless active load balance
between the idle CPU and the busy CPU.
We need to reset of the imbalance flag as soon as we have reached a balanced
state. If all tasks are pinned, we don't consider that as a balanced state and
let the imbalance flag set.
sched: Add default-disabled option to BUG() when stack end location is overwritten
Currently in the event of a stack overrun a call to schedule()
does not check for this type of corruption. This corruption is
often silent and can go unnoticed. However once the corrupted
region is examined at a later stage, the outcome is undefined
and often results in a sporadic page fault which cannot be
handled.
This patch checks for a stack overrun and takes appropriate
action since the damage is already done, there is no point
in continuing.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: aneesh.kumar@linux.vnet.ibm.com Cc: dzickus@redhat.com Cc: bmr@redhat.com Cc: jcastillo@redhat.com Cc: oleg@redhat.com Cc: riel@redhat.com Cc: prarit@redhat.com Cc: jgh@redhat.com Cc: minchan@kernel.org Cc: mpe@ellerman.id.au Cc: tglx@linutronix.de Cc: rostedt@goodmis.org Cc: hannes@cmpxchg.org Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: David S. Miller <davem@davemloft.net> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lubomir Rintel <lkundrak@v3.sk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1410527779-8133-4-git-send-email-atomlin@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tasks get their end of stack set to STACK_END_MAGIC with the
aim to catch stack overruns. Currently this feature does not
apply to init_task. This patch removes this restriction.
Note that a similar patch was posted by Prarit Bhargava
some time ago but was never merged:
sched, time: Fix lock inversion in thread_group_cputime()
The sig->stats_lock nests inside the tasklist_lock and the
sighand->siglock in __exit_signal and wait_task_zombie.
However, both of those locks can be taken from irq context,
which means we need to use the interrupt safe variant of
read_seqbegin_or_lock. This blocks interrupts when the "lock"
branch is taken (seq is odd), preventing the lock inversion.
On the first (lockless) pass through the loop, irqs are not
blocked.
seqlock: Add irqsave variant of read_seqbegin_or_lock()
There are cases where read_seqbegin_or_lock() needs to block irqs,
because the seqlock in question nests inside a lock that is also
be taken from irq context.
Add read_seqbegin_or_lock_irqsave() and done_seqretry_irqrestore(), which
are almost identical to read_seqbegin_or_lock() and done_seqretry().
Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: prarit@redhat.com Cc: oleg@redhat.com Cc: sgruszka@redhat.com Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Link: http://lkml.kernel.org/r/1410527535-9814-2-git-send-email-riel@redhat.com
[ Improved the readability of the code a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Chuansheng Liu [Thu, 4 Sep 2014 07:17:54 +0000 (15:17 +0800)]
smp: Add new wake_up_all_idle_cpus() function
Currently kick_all_cpus_sync() can break non-polling idle cpus
thru IPI interrupts.
But sometimes we need to break the polling idle cpus immediately
to reselect the suitable c-state, also for non-idle cpus, we need
to do nothing if we try to wake up them.
Here adding one new function wake_up_all_idle_cpus() to let all cpus
out of idle based on function wake_up_if_idle().
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: daniel.lezcano@linaro.org Cc: rjw@rjwysocki.net Cc: linux-pm@vger.kernel.org Cc: changcheng.liu@intel.com Cc: xiaoming.wang@intel.com Cc: souvik.k.chakravarty@intel.com Cc: luto@amacapital.net Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1409815075-4180-2-git-send-email-chuansheng.liu@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/numa: Use select_idle_sibling() to select a destination for task_numa_move()
The code in task_numa_compare() will only examine at most one idle CPU per node,
because they all have the same score. However, some idle CPUs are better
candidates than others, due to busy or idle SMT siblings, etc...
The scheduler has logic to find the best CPU within an LLC to place a
task. The NUMA code should probably use it.
This seems to reduce the standard deviation for single instance SPECjbb2005
with a low warehouse count on my 4 node test system.
Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: mgorman@suse.de Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140904163530.189d410a@cuia.bos.redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Juri Lelli [Tue, 9 Sep 2014 09:57:15 +0000 (10:57 +0100)]
Documentation/scheduler/sched-deadline.txt: Add tests suite appendix
Add an appendix briefly describing tools that can be used to
test SCHED_DEADLINE (and the scheduler in general). Links to
where source code of the tools is hosted are also provided.
Signed-off-by: Juri Lelli <juri.lelli@arm.com> Reviewed-by: Henrik Austad <henrik@austad.us> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dario Faggioli <raistlin@linux.it> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1410256636-26171-5-git-send-email-juri.lelli@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Documentation/scheduler/sched-deadline.txt: Improve and clarify AC bits
Admission control is of key importance for SCHED_DEADLINE, since
it guarantees system schedulability (or tells us something about
the degree of guarantees we can provide to the user).
This patch improves and clarifies bits and pieces regarding AC,
both for UP and SMP systems.
Signed-off-by: Luca Abeni <luca.abeni@unitn.it> Signed-off-by: Juri Lelli <juri.lelli@arm.com> Reviewed-by: Henrik Austad <henrik@austad.us> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dario Faggioli <raistlin@linux.it> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1410256636-26171-4-git-send-email-juri.lelli@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Jason Low [Tue, 2 Sep 2014 07:41:24 +0000 (00:41 -0700)]
sched: Reduce contention in update_cfs_rq_blocked_load()
When running workloads on 2+ socket systems, based on perf profiles, the
update_cfs_rq_blocked_load() function often shows up as taking up a
noticeable % of run time.
Much of the contention is in __update_cfs_rq_tg_load_contrib() when we
update the tg load contribution stats. However, it turns out that in many
cases, they don't need to be updated and "tg_contrib" is 0.
This patch adds a check in __update_cfs_rq_tg_load_contrib() to skip updating
tg load contribution stats when nothing needs to be updated. This reduces the
cacheline contention that would be unnecessary.
Reviewed-by: Ben Segall <bsegall@google.com> Reviewed-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Jason Low <jason.low2@hp.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Paul Turner <pjt@google.com> Cc: jason.low2@hp.com Cc: Yuyang Du <yuyang.du@intel.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Chegu Vinod <chegu_vinod@hp.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1409643684.19197.15.camel@j-VirtualBox Signed-off-by: Ingo Molnar <mingo@kernel.org>
Lai Jiangshan [Wed, 4 Jun 2014 08:25:15 +0000 (16:25 +0800)]
sched: Migrate waking tasks
Current code can fail to migrate a waking task (silently) when TTWU_QUEUE is
enabled.
When a task is waking, it is pending on the wake_list of the rq, but it is not
queued (task->on_rq == 0). In this case, set_cpus_allowed_ptr() and
__migrate_task() will not migrate it because its invisible to them.
This behavior is incorrect, because the task has been already woken, it will be
running on the wrong CPU without correct placement until the next wake-up or
update for cpus_allowed.
To fix this problem, we need to finish the wakeup (so they appear on
the runqueue) before we migrate them.
Reported-by: Sasha Levin <sasha.levin@oracle.com> Reported-by: Jason J. Herne <jjherne@linux.vnet.ibm.com> Tested-by: Jason J. Herne <jjherne@linux.vnet.ibm.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/538ED7EB.5050303@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Rik van Riel [Fri, 15 Aug 2014 20:05:38 +0000 (16:05 -0400)]
sched, time: Atomically increment stime & utime
The functions task_cputime_adjusted and thread_group_cputime_adjusted()
can be called locklessly, as well as concurrently on many different CPUs.
This can occasionally lead to the utime and stime reported by times(), and
other syscalls like it, going backward. The cause for this appears to be
multiple threads racing in cputime_adjust(), both with values for utime or
stime that is larger than the original, but each with a different value.
Sometimes the larger value gets saved first, only to be immediately
overwritten with a smaller value by another thread.
Using atomic exchange prevents that problem, and ensures time
progresses monotonically.
Rik van Riel [Sat, 16 Aug 2014 17:40:10 +0000 (13:40 -0400)]
time, signal: Protect resource use statistics with seqlock
Both times() and clock_gettime(CLOCK_PROCESS_CPUTIME_ID) have scalability
issues on large systems, due to both functions being serialized with a
lock.
The lock protects against reporting a wrong value, due to a thread in the
task group exiting, its statistics reporting up to the signal struct, and
that exited task's statistics being counted twice (or not at all).
Protecting that with a lock results in times() and clock_gettime() being
completely serialized on large systems.
This can be fixed by using a seqlock around the events that gather and
propagate statistics. As an additional benefit, the protection code can
be moved into thread_group_cputime(), slightly simplifying the calling
functions.
In the case of posix_cpu_clock_get_task() things can be simplified a
lot, because the calling function already ensures that the task sticks
around, and the rest is now taken care of in thread_group_cputime().
This way the statistics reporting code can run lockless.
Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Daeseok Youn <daeseok.youn@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guillaume Morin <guillaume@morinfr.org> Cc: Ionut Alexa <ionut.m.alexa@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Michal Schmidt <mschmidt@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: umgwanakikbuti@gmail.com Cc: fweisbec@gmail.com Cc: srao@redhat.com Cc: lwoodman@redhat.com Cc: atheurer@redhat.com Link: http://lkml.kernel.org/r/20140816134010.26a9b572@annuminas.surriel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Rik van Riel [Fri, 15 Aug 2014 20:05:36 +0000 (16:05 -0400)]
exit: Always reap resource stats in __exit_signal()
Oleg pointed out that wait_task_zombie adds a task's usage statistics
to the parent's signal struct, but the task's own signal struct should
also propagate the statistics at exit time.
This allows thread_group_cputime(reaped_zombie) to get the statistics
after __unhash_process() has made the task invisible to for_each_thread,
but before the thread has actually been rcu freed, making sure no
non-monotonic results are returned inside that window.
Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Guillaume Morin <guillaume@morinfr.org> Cc: Ionut Alexa <ionut.m.alexa@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Michal Schmidt <mschmidt@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: umgwanakikbuti@gmail.com Cc: fweisbec@gmail.com Cc: srao@redhat.com Cc: lwoodman@redhat.com Cc: atheurer@redhat.com Link: http://lkml.kernel.org/r/1408133138-22048-2-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Paul Bolle [Sun, 7 Sep 2014 18:25:55 +0000 (11:25 -0700)]
Documentation: NFS/RDMA: Document separate Kconfig symbols
The NFS/RDMA Kconfig symbol was split into separate options for client
and server in commit 2e8c12e1b765 ("xprtrdma: add separate Kconfig
options for NFSoRDMA client and server support").
Update the documentation to reflect this split.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: "J. Bruce Fields" <bfields@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Despite the fact that these functions have been around for years, they
are little used (only 15 uses in 13 files at the preseht time) even
though many other files use work-arounds to achieve the same result.
By documenting them, hopefully they will become more widely used.
Signed-off-by: Rob Jones <rob.jones@codethink.co.uk> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'pm+acpi-3.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management fixes from Rafael Wysocki:
"These are regression fixes (ACPI sysfs, ACPI video, suspend test),
ACPI cpuidle deadlock fix, missing runtime validation of ACPI _DSD
output, a fix and a new CPU ID for the RAPL driver, new blacklist
entry for the ACPI EC driver and a couple of trivial cleanups
(intel_pstate and generic PM domains).
Specifics:
- Fix for recently broken test_suspend= command line argument (Rafael
Wysocki).
- Fixes for regressions related to the ACPI video driver caused by
switching the default to native backlight handling in 3.16 from
Hans de Goede.
- Fix for a sysfs attribute of ACPI device objects that returns stale
values sometimes due to the fact that they are cached instead of
executing the appropriate method (_SUN) every time (broken in
3.14). From Yasuaki Ishimatsu.
- Fix for a deadlock between cpuidle_lock and cpu_hotplug.lock in the
ACPI processor driver from Jiri Kosina.
- Runtime output validation for the ACPI _DSD device configuration
object missing from the support for it that has been introduced
recently. From Mika Westerberg.
- Fix for an unuseful and misleading RAPL (Running Average Power
Limit) domain detection message in the RAPL driver from Jacob Pan.
- New Intel Haswell CPU ID for the RAPL driver from Jason Baron.
- New Clevo W350etq blacklist entry for the ACPI EC driver from Lan
Tianyu.
- Cleanup for the intel_pstate driver and the core generic PM domains
code from Gabriele Mazzotta and Geert Uytterhoeven"
* tag 'pm+acpi-3.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / cpuidle: fix deadlock between cpuidle_lock and cpu_hotplug.lock
ACPI / scan: not cache _SUN value in struct acpi_device_pnp
cpufreq: intel_pstate: Remove unneeded variable
powercap / RAPL: change domain detection message
powercap / RAPL: add support for CPU model 0x3f
PM / domains: Make generic_pm_domain.name const
PM / sleep: Fix test_suspend= command line option
ACPI / EC: Add msi quirk for Clevo W350etq
ACPI / video: Disable native_backlight on HP ENVY 15 Notebook PC
ACPI / video: Add a disable_native_backlight quirk
ACPI / video: Fix use_native_backlight selection logic
ACPICA: ACPI 5.1: Add support for runtime validation of _DSD package.
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull filesystem fixes from Al Viro:
"Several bugfixes (all of them -stable fodder).
Alexey's one deals with double mutex_lock() in UFS (apparently, nobody
has tried to test "ufs: sb mutex merge + mutex_destroy" on something
like file creation/removal on ufs). Mine deal with two kinds of
umount bugs, in umount propagation and in handling of automounted
submounts, both resulting in bogus transient EBUSY from umount"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ufs: fix deadlocks introduced by sb mutex merge
fix EBUSY on umount() from MNT_SHRINKABLE
get rid of propagate_umount() mistakenly treating slaves as busy.
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU fix from Ingo Molnar:
"A boot hang fix for the offloaded callback RCU model (RCU_NOCB_CPU=y
&& (TREE_CPU=y || TREE_PREEMPT_RC)) in certain bootup scenarios"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcu: Make nocb leader kthreads process pending callbacks after spawning
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"Three fixlets from the timer departement:
- Update the timekeeper before updating vsyscall and pvclock. This
fixes the kvm-clock regression reported by Chris and Paolo.
- Use the proper irq work interface from NMI. This fixes the
regression reported by Catalin and Dave.
- Clarify the compat_nanosleep error handling mechanism to avoid
future confusion"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Update timekeeper before updating vsyscall and pvclock
compat: nanosleep: Clarify error handling
nohz: Restore NMI safe local irq work for local nohz kick
Commit 0244756edc4b ("ufs: sb mutex merge + mutex_destroy") introduces
deadlocks in ufs_new_inode() and ufs_free_inode().
Most callers of that functions acqure the mutex by themselves and
ufs_{new,free}_inode() do that via lock_ufs(),
i.e we have an unavoidable double lock.
The patch proposes to resolve the issue by making sure that
ufs_{new,free}_inode() are not called with the mutex held.
Found by Linux Driver Verification project (linuxtesting.org).
The correct runtime should be less than or equal to 200us at some point.
The problem is caused by a conditional judgment "delta > 10000"
in function start_hrtick_dl().
Because no hrtimer start up to control the rest of runtime
when the reset of runtime is less than 10us.
So the process will continue to run until tick-period is coming.
Move the code with the limit of the least time slice
from hrtick_start_fair() to hrtick_start() because the
EDF schedule class also needs this function in start_hrtick_dl().
To fix this problem, we call hrtimer_start() unconditionally in
start_hrtick_dl(), and make sure the scheduling slice won't be smaller
than 10us in hrtimer_start().
Signed-off-by: Xiaofeng Yan <xiaofeng.yan@huawei.com> Reviewed-by: Li Zefan <lizefan@huawei.com> Acked-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1409022941-5880-1-git-send-email-xiaofeng.yan@huawei.com
[ Massaged the changelog and the code. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"A smattering of bug fixes across most architectures"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
powerpc/kvm/cma: Fix panic introduces by signed shift operation
KVM: s390/mm: Fix guest storage key corruption in ptep_set_access_flags
KVM: s390/mm: Fix storage key corruption during swapping
arm/arm64: KVM: Complete WFI/WFE instructions
ARM/ARM64: KVM: Nuke Hyp-mode tlbs before enabling MMU
KVM: s390/mm: try a cow on read only pages for key ops
KVM: s390: Fix user triggerable bug in dead code
Merge tag 'xfs-for-linus-3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs
Pull xfs fixes from Dave Chinner:
"The fixes all address recently discovered data corruption issues.
The original Direct IO issue was discovered by Chris Mason @ Facebook
on a production workload which mixed buffered reads with direct reads
and writes IO to the same file. The fix for that exposed other issues
with page invalidation (exposed by millions of fsx operations) failing
due to dirty buffers beyond EOF.
Finally, the collapse_range code could also cause problems due to
racing writeback changing the extent map while it was being shifted
around. The commits for that problem are simple mitigation fixes that
prevent the problem from occuring. A more robust fix for 3.18 that
addresses the underlying problem is currently being worked on by
Brian.
Summary of fixes:
- a direct IO read/buffered read data corruption
- the associated fallout from the DIO data corruption fix
- collapse range bugs that are potential data corruption issues"
* tag 'xfs-for-linus-3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
xfs: trim eofblocks before collapse range
xfs: xfs_file_collapse_range is delalloc challenged
xfs: don't log inode unless extent shift makes extent modifications
xfs: use ranged writeback and invalidation for direct IO
xfs: don't zero partial page cache pages during O_DIRECT writes
xfs: don't zero partial page cache pages during O_DIRECT writes
xfs: don't dirty buffers beyond EOF
Merge tag 'for-linus-20140905' of git://git.infradead.org/linux-mtd
Pull mtd fixes from Brian Norris:
"Two trivial MTD updates for 3.17-rc4:
- a tiny comment tweak, to kill a bunch of DocBook warnings added
during the merge window
- a small fixup to the OTP routines' error handling"
* tag 'for-linus-20140905' of git://git.infradead.org/linux-mtd:
mtd: nand: fix DocBook warnings on nand_sdr_timings doc
mtd: cfi_cmdset_0002: check return code for get_chip()
Thomas Gleixner [Sat, 6 Sep 2014 10:24:49 +0000 (12:24 +0200)]
timekeeping: Update timekeeper before updating vsyscall and pvclock
The update_walltime() code works on the shadow timekeeper to make the
seqcount protected region as short as possible. But that update to the
shadow timekeeper does not update all timekeeper fields because it's
sufficient to do that once before it becomes life. One of these fields
is tkr.base_mono. That stays stale in the shadow timekeeper unless an
operation happens which copies the real timekeeper to the shadow.
The update function is called after the update calls to vsyscall and
pvclock. While not correct, it did not cause any problems because none
of the invoked update functions used base_mono.
commit cbcf2dd3b3d4 (x86: kvm: Make kvm_get_time_and_clockread()
nanoseconds based) changed that in the kvm pvclock update function, so
the stale mono_base value got used and caused kvm-clock to malfunction.
Put the update where it belongs and fix the issue.
Reported-by: Chris J Arges <chris.j.arges@canonical.com> Reported-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1409050000570.3333@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Thomas Gleixner [Sat, 6 Sep 2014 10:18:07 +0000 (12:18 +0200)]
compat: nanosleep: Clarify error handling
The error handling in compat_sys_nanosleep() is correct, but
completely non obvious. Document it and restrict it to the
-ERESTART_RESTARTBLOCK return value for clarity.
Reported-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c bugfixes from Wolfram Sang:
"I2C driver bugfixes for the 3.17 release. Details can be found in the
commit messages, yet I think this is typical driver stuff"
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
Revert "i2c: rcar: remove spinlock"
i2c: at91: add bound checking on SMBus block length bytes
i2c: rk3x: fix bug that cause transfer fails in master receive mode
i2c: at91: Fix a race condition during signal handling in at91_do_twi_xfer.
i2c: mv64xxx: continue probe when clock-frequency is missing
i2c: rcar: fix MNR interrupt handling
The function cleaning up an initialized event
was called from the "event_del" handler, instead
of being used as the "destroy" callback. In case of
events group allocation this caused NULL pointer
dereference (as events are added and deleted
multiple times then). Fixed now.
Signed-off-by: Pawel Moll <mail@pawelmoll.com> Signed-off-by: Kevin Hilman <khilman@linaro.org>
Actually register clocks from device tree when using the common clock
framework.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[nicolas.ferre@atmel.com: add at91 to function name] Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Johannes Weiner [Fri, 5 Sep 2014 12:43:57 +0000 (08:43 -0400)]
mm: memcontrol: revert use of root_mem_cgroup res_counter
Dave Hansen reports a massive scalability regression in an uncontained
page fault benchmark with more than 30 concurrent threads, which he
bisected down to 05b843012335 ("mm: memcontrol: use root_mem_cgroup
res_counter") and pin-pointed on res_counter spinlock contention.
That change relied on the per-cpu charge caches to mostly swallow the
res_counter costs, but it's apparent that the caches don't scale yet.
Revert memcg back to bypassing res_counters on the root level in order
to restore performance for uncontained workloads.
Reported-by: Dave Hansen <dave@sr71.net> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Dave Hansen <dave.hansen@intel.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Export sync_filesystem() for modular ->remount_fs() use
This patch changes sync_filesystem() to be EXPORT_SYMBOL().
The reason this is needed is that starting with 3.15 kernel, due to
Theodore Ts'o's commit 02b9984d6408 ("fs: push sync_filesystem() down to
the file system's remount_fs()"), all file systems that have dirty data
to be written out need to call sync_filesystem() from their
->remount_fs() method when remounting read-only.
As this is now a generically required function rather than an internal
only function it should be EXPORT_SYMBOL() so that all file systems can
call it.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'regulator-v3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator documentation fixes from Mark Brown:
"All the fixes people have found for the regulator API have been
documentation fixes, avoiding warnings while building the kerneldoc,
fixing some errors in one of the DT bindings documents and fixing some
typos in the header"
* tag 'regulator-v3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: fix kernel-doc warnings in header files
regulator: Proofread documentation
regulator: tps65090: Fix tps65090 typos in example
Kevin Hilman [Fri, 5 Sep 2014 15:01:52 +0000 (08:01 -0700)]
Merge tag 'omap-fixes-against-v3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes
Merge "omap fixes against v3.17-rc3" from Tony Lindgren:
Few fixes for omaps mostly for various devices to get them working
properly on the new am437x and dra7 hardware for several devices
such as I2C, NAND, DDR3 and USB. There's also a clock fix for omap3.
And also included are two minor cosmetic fixes that are not
stictly fixes for the new hardware support added recently to
downgrade a GPMC warning into a debug statement, and fix the
confusing comments for dra7-evm spi1 mux.
Note that these are all .dts changes except for a GPMC change.
* tag 'omap-fixes-against-v3.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (255 commits)
ARM: dts: dra7-evm: Add vtt regulator support
ARM: dts: dra7-evm: Fix spi1 mux documentation
ARM: dts: am43x-epos-evm: Disable QSPI to prevent conflict with GPMC-NAND
ARM: OMAP2+: gpmc: Don't complain if wait pin is used without r/w monitoring
ARM: dts: am43xx-epos-evm: Don't use read/write wait monitoring
ARM: dts: am437x-gp-evm: Don't use read/write wait monitoring
ARM: dts: am437x-gp-evm: Use BCH16 ECC scheme instead of BCH8
ARM: dts: am43x-epos-evm: Use BCH16 ECC scheme instead of BCH8
ARM: dts: am4372: fix USB regs size
ARM: dts: am437x-gp: switch i2c0 to 100KHz
ARM: dts: dra7-evm: Fix 8th NAND partition's name
ARM: dts: dra7-evm: Fix i2c3 pinmux and frequency
Linux 3.17-rc3
...
Merge tag 'gpio-v3.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO fixes from Linus Walleij:
- some documentation sync
- resource leak in the bt8xx driver
- again fix the way varargs are used to handle the optional flags on
the gpiod_* accessors. Now hopefully nailed the entire problem.
* tag 'gpio-v3.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
gpio: move varargs hack outside #ifdef GPIOLIB
gpio: bt8xx: fix release of managed resources
Documentation: gpio: documentation for optional getters functions
aio: block exit_aio() until all context requests are completed
It seems that exit_aio() also needs to wait for all iocbs to complete (like
io_destroy), but we missed the wait step in current implemention, so fix
it in the same way as we did in io_destroy.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Cc: stable@vger.kernel.org
nohz: Restore NMI safe local irq work for local nohz kick
The local nohz kick is currently used by perf which needs it to be
NMI-safe. Recent commit though (7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9)
changed its implementation to fire the local kick using the remote kick
API. It was convenient to make the code more generic but the remote kick
isn't NMI-safe.
Lets fix this by restoring the use of local irq work for the nohz local
kick.
Reported-by: Catalin Iacob <iacobcatalin@gmail.com> Reported-and-tested-by: Dave Jones <davej@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Merge tag 'davinci-fixes-for-v3.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci into fixes
This patch fixes setup of second EDMA channel controller
on DA850.
* tag 'davinci-fixes-for-v3.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci:
ARM: edma: Fix configuration parsing for SoCs with multiple eDMA3 CC
DRA7 evm REV G and later boards uses a vtt regulator for DDR3
termination and this is controlled by gpio7_11. This gpio is
configured in boot loader. gpio7_11, which is only available only on
Pad A22, in previous boards, is connected only to an unused pad on
expansion connector EXP_P3 and is safe to be muxed as GPIO on all
DRA7-evm versions (without a need to spin off another dts file).
Since gpio7_11 is used to control VTT and should not be reset or kept
in idle state during boot up else VTT will be disconnected and DDR
gets corrupted. So, as part of this change, mark gpio7 as no-reset and
no-idle on init.
While auditing the various pin ctrl configurations using the following
command:
grep PIN_ arch/arm/boot/dts/dra7-evm.dts|(while read line;
do
v=`echo "$line" | sed -e "s/\s\s*/|/g" | cut -d '|' -f1 |
cut -d 'x' -f2|tr [a-z] [A-Z]`;
HEX=`echo "obase=16;ibase=16;4A003400+$v"| bc`;
echo "$HEX ===> $line";
done)
against DRA75x/74x NDA TRM revision S(SPRUHI2S August 2014),
documentation errors were found for spi1 pinctrl. Fix the same.
Fixes: 6e58b8f1daaf1af ("ARM: dts: DRA7: Add the dts files for dra7 SoC and dra7-evm board") Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
Roger Quadros [Tue, 2 Sep 2014 13:57:06 +0000 (16:57 +0300)]
ARM: OMAP2+: gpmc: Don't complain if wait pin is used without r/w monitoring
For NAND read & write wait pin monitoring must be kept disabled as the
wait pin is only used to indicate NAND device ready status and not to
extend each read/write cycle.
So don't print a warning if wait pin is specified while read/write
monitoring is not in the device tree.
Sanity check wait pin number irrespective if read/write monitoring is
set or not.
Signed-off-by: Roger Quadros <rogerq@ti.com> Reviewed-by: Pekon Gupta <pekon@pek-sem.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
Roger Quadros [Tue, 2 Sep 2014 13:57:05 +0000 (16:57 +0300)]
ARM: dts: am43xx-epos-evm: Don't use read/write wait monitoring
NAND uses wait pin only to indicate device readiness after
a block/page operation. It is not use to extend individual
read/write cycle and so read/write wait pin monitoring must
be disabled for NAND.
Add gpmc wait pin information as the NAND uses wait pin 0
for device ready indication.
Signed-off-by: Roger Quadros <rogerq@ti.com> Reviewed-by: Pekon Gupta <pekon@pek-sem.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
Roger Quadros [Tue, 2 Sep 2014 13:57:04 +0000 (16:57 +0300)]
ARM: dts: am437x-gp-evm: Don't use read/write wait monitoring
NAND uses wait pin only to indicate device readiness after
a block/page operation. It is not use to extend individual
read/write cycle and so read/write wait pin monitoring must
be disabled for NAND.
This patch also gets rid of the below warning when NAND is
accessed for the first time.
Roger Quadros [Tue, 2 Sep 2014 13:57:03 +0000 (16:57 +0300)]
ARM: dts: am437x-gp-evm: Use BCH16 ECC scheme instead of BCH8
am437x-gp-evm uses a NAND chip with page size 4096 bytes
and spare area of 225 bytes per page.
For such a setup it is preferrable to use BCH16 ECC scheme over
BCH8. This also makes it compatible with ROM code ECC scheme so
we can boot with NAND after flashing from kernel.
Signed-off-by: Roger Quadros <rogerq@ti.com> Reviewed-by: Pekon Gupta <pekon@pek-sem.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
Roger Quadros [Tue, 2 Sep 2014 13:57:02 +0000 (16:57 +0300)]
ARM: dts: am43x-epos-evm: Use BCH16 ECC scheme instead of BCH8
am43x-epos-evm uses a NAND chip with page size 4096 bytes
and spare area of 225 bytes per page.
For such a setup it is preferrable to use BCH16 ECC scheme over
BCH8. This also makes it compatible with ROM code ECC scheme so
we can boot with NAND after flashing from kernel.
Signed-off-by: Roger Quadros <rogerq@ti.com> Reviewed-by: Pekon Gupta <pekon@pek-sem.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
projects / linux-beck.git / log