rcu: Fix deadlock with CPU hotplug, RCU GP init, and timer migration
In Steven Rostedt's words:
> I've been debugging the last couple of days why my tests have been
> locking up. One of my tracing tests, runs all available tracers. The
> lockup always happened with the mmiotrace, which is used to trace
> interactions between priority drivers and the kernel. But to do this
> easily, when the tracer gets registered, it disables all but the boot
> CPUs. The lockup always happened after it got done disabling the CPUs.
>
> Then I decided to try this:
>
> while :; do
> for i in 1 2 3; do
> echo 0 > /sys/devices/system/cpu/cpu$i/online
> done
> for i in 1 2 3; do
> echo 1 > /sys/devices/system/cpu/cpu$i/online
> done
> done
>
> Well, sure enough, that locked up too, with the same users. Doing a
> sysrq-w (showing all blocked tasks):
>
> [ 2991.344562] task PC stack pid father
> [ 2991.344562] rcu_preempt D ffff88007986fdf8 0 10 2 0x00000000
> [ 2991.344562] ffff88007986fc980000000000000002ffff88007986fc480000000000000908
> [ 2991.344562] ffff88007986c280ffff88007986ffd8ffff88007986ffd800000000001d3c80
> [ 2991.344562] ffff880079248a40ffff88007986c280000000000000000000000000fffd4295
> [ 2991.344562] Call Trace:
> [ 2991.344562] [<ffffffff815437ba>] schedule+0x64/0x66
> [ 2991.344562] [<ffffffff81541750>] schedule_timeout+0xbc/0xf9
> [ 2991.344562] [<ffffffff8154bec0>] ? ftrace_call+0x5/0x2f
> [ 2991.344562] [<ffffffff81049513>] ? cascade+0xa8/0xa8
> [ 2991.344562] [<ffffffff815417ab>] schedule_timeout_uninterruptible+0x1e/0x20
> [ 2991.344562] [<ffffffff810c980c>] rcu_gp_kthread+0x502/0x94b
> [ 2991.344562] [<ffffffff81062791>] ? __init_waitqueue_head+0x50/0x50
> [ 2991.344562] [<ffffffff810c930a>] ? rcu_gp_fqs+0x64/0x64
> [ 2991.344562] [<ffffffff81061cdb>] kthread+0xb1/0xb9
> [ 2991.344562] [<ffffffff81091e31>] ? lock_release_holdtime.part.23+0x4e/0x55
> [ 2991.344562] [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562] [<ffffffff8154c1dc>] ret_from_fork+0x7c/0xb0
> [ 2991.344562] [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562] kworker/0:1 D ffffffff81a30680 0 47 2 0x00000000
> [ 2991.344562] Workqueue: events cpuset_hotplug_workfn
> [ 2991.344562] ffff880078dbbb580000000000000002000000000000000600000000000000d8
> [ 2991.344562] ffff880078db8100ffff880078dbbfd8ffff880078dbbfd800000000001d3c80
> [ 2991.344562] ffff8800779ca5c0ffff880078db8100ffffffff81541fcf0000000000000000
> [ 2991.344562] Call Trace:
> [ 2991.344562] [<ffffffff81541fcf>] ? __mutex_lock_common+0x3d4/0x609
> [ 2991.344562] [<ffffffff815437ba>] schedule+0x64/0x66
> [ 2991.344562] [<ffffffff81543a39>] schedule_preempt_disabled+0x18/0x24
> [ 2991.344562] [<ffffffff81541fcf>] __mutex_lock_common+0x3d4/0x609
> [ 2991.344562] [<ffffffff8103d11b>] ? get_online_cpus+0x3c/0x50
> [ 2991.344562] [<ffffffff8103d11b>] ? get_online_cpus+0x3c/0x50
> [ 2991.344562] [<ffffffff815422ff>] mutex_lock_nested+0x3b/0x40
> [ 2991.344562] [<ffffffff8103d11b>] get_online_cpus+0x3c/0x50
> [ 2991.344562] [<ffffffff810af7e6>] rebuild_sched_domains_locked+0x6e/0x3a8
> [ 2991.344562] [<ffffffff810b0ec6>] rebuild_sched_domains+0x1c/0x2a
> [ 2991.344562] [<ffffffff810b109b>] cpuset_hotplug_workfn+0x1c7/0x1d3
> [ 2991.344562] [<ffffffff810b0ed9>] ? cpuset_hotplug_workfn+0x5/0x1d3
> [ 2991.344562] [<ffffffff81058e07>] process_one_work+0x2d4/0x4d1
> [ 2991.344562] [<ffffffff81058d3a>] ? process_one_work+0x207/0x4d1
> [ 2991.344562] [<ffffffff8105964c>] worker_thread+0x2e7/0x3b5
> [ 2991.344562] [<ffffffff81059365>] ? rescuer_thread+0x332/0x332
> [ 2991.344562] [<ffffffff81061cdb>] kthread+0xb1/0xb9
> [ 2991.344562] [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562] [<ffffffff8154c1dc>] ret_from_fork+0x7c/0xb0
> [ 2991.344562] [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562] bash D ffffffff81a4aa80 0 2618 2612 0x10000000
> [ 2991.344562] ffff8800379abb58000000000000000200000000000000060000000000000c2c
> [ 2991.344562] ffff880077fea140ffff8800379abfd8ffff8800379abfd800000000001d3c80
> [ 2991.344562] ffff8800779ca5c0ffff880077fea140ffffffff81541fcf0000000000000000
> [ 2991.344562] Call Trace:
> [ 2991.344562] [<ffffffff81541fcf>] ? __mutex_lock_common+0x3d4/0x609
> [ 2991.344562] [<ffffffff815437ba>] schedule+0x64/0x66
> [ 2991.344562] [<ffffffff81543a39>] schedule_preempt_disabled+0x18/0x24
> [ 2991.344562] [<ffffffff81541fcf>] __mutex_lock_common+0x3d4/0x609
> [ 2991.344562] [<ffffffff81530078>] ? rcu_cpu_notify+0x2f5/0x86e
> [ 2991.344562] [<ffffffff81530078>] ? rcu_cpu_notify+0x2f5/0x86e
> [ 2991.344562] [<ffffffff815422ff>] mutex_lock_nested+0x3b/0x40
> [ 2991.344562] [<ffffffff81530078>] rcu_cpu_notify+0x2f5/0x86e
> [ 2991.344562] [<ffffffff81091c99>] ? __lock_is_held+0x32/0x53
> [ 2991.344562] [<ffffffff81548912>] notifier_call_chain+0x6b/0x98
> [ 2991.344562] [<ffffffff810671fd>] __raw_notifier_call_chain+0xe/0x10
> [ 2991.344562] [<ffffffff8103cf64>] __cpu_notify+0x20/0x32
> [ 2991.344562] [<ffffffff8103cf8d>] cpu_notify_nofail+0x17/0x36
> [ 2991.344562] [<ffffffff815225de>] _cpu_down+0x154/0x259
> [ 2991.344562] [<ffffffff81522710>] cpu_down+0x2d/0x3a
> [ 2991.344562] [<ffffffff81526351>] store_online+0x4e/0xe7
> [ 2991.344562] [<ffffffff8134d764>] dev_attr_store+0x20/0x22
> [ 2991.344562] [<ffffffff811b3c5f>] sysfs_write_file+0x108/0x144
> [ 2991.344562] [<ffffffff8114c5ef>] vfs_write+0xfd/0x158
> [ 2991.344562] [<ffffffff8114c928>] SyS_write+0x5c/0x83
> [ 2991.344562] [<ffffffff8154c494>] tracesys+0xdd/0xe2
>
> As well as held locks:
>
> [ 3034.728033] Showing all locks held in the system:
> [ 3034.728033] 1 lock held by rcu_preempt/10:
> [ 3034.728033] #0: (rcu_preempt_state.onoff_mutex){+.+...}, at: [<ffffffff810c9471>] rcu_gp_kthread+0x167/0x94b
> [ 3034.728033] 4 locks held by kworker/0:1/47:
> [ 3034.728033] #0: (events){.+.+.+}, at: [<ffffffff81058d3a>] process_one_work+0x207/0x4d1
> [ 3034.728033] #1: (cpuset_hotplug_work){+.+.+.}, at: [<ffffffff81058d3a>] process_one_work+0x207/0x4d1
> [ 3034.728033] #2: (cpuset_mutex){+.+.+.}, at: [<ffffffff810b0ec1>] rebuild_sched_domains+0x17/0x2a
> [ 3034.728033] #3: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8103d11b>] get_online_cpus+0x3c/0x50
> [ 3034.728033] 1 lock held by mingetty/2563:
> [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2565:
> [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2569:
> [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2572:
> [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2575:
> [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 7 locks held by bash/2618:
> [ 3034.728033] #0: (sb_writers#5){.+.+.+}, at: [<ffffffff8114bc3f>] file_start_write+0x2a/0x2c
> [ 3034.728033] #1: (&buffer->mutex#2){+.+.+.}, at: [<ffffffff811b3b93>] sysfs_write_file+0x3c/0x144
> [ 3034.728033] #2: (s_active#54){.+.+.+}, at: [<ffffffff811b3c3e>] sysfs_write_file+0xe7/0x144
> [ 3034.728033] #3: (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff810217c2>] cpu_hotplug_driver_lock+0x17/0x19
> [ 3034.728033] #4: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff8103d196>] cpu_maps_update_begin+0x17/0x19
> [ 3034.728033] #5: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8103cfd8>] cpu_hotplug_begin+0x2c/0x6d
> [ 3034.728033] #6: (rcu_preempt_state.onoff_mutex){+.+...}, at: [<ffffffff81530078>] rcu_cpu_notify+0x2f5/0x86e
> [ 3034.728033] 1 lock held by bash/2980:
> [ 3034.728033] #0: (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
>
> Things looked a little weird. Also, this is a deadlock that lockdep did
> not catch. But what we have here does not look like a circular lock
> issue:
>
> Bash is blocked in rcu_cpu_notify():
>
> 1961 /* Exclude any attempts to start a new grace period. */
> 1962 mutex_lock(&rsp->onoff_mutex);
>
>
> kworker is blocked in get_online_cpus(), which makes sense as we are
> currently taking down a CPU.
>
> But rcu_preempt is not blocked on anything. It is simply sleeping in
> rcu_gp_kthread (really rcu_gp_init) here:
>
> 1453 #ifdef CONFIG_PROVE_RCU_DELAY
> 1454 if ((prandom_u32() % (rcu_num_nodes * 8)) == 0 &&
> 1455 system_state == SYSTEM_RUNNING)
> 1456 schedule_timeout_uninterruptible(2);
> 1457 #endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
>
> And it does this while holding the onoff_mutex that bash is waiting for.
>
> Doing a function trace, it showed me where it happened:
>
> [ 125.940066] rcu_pree-10 3.... 28384115273: schedule_timeout_uninterruptible <-rcu_gp_kthread
> [...]
> [ 125.940066] rcu_pree-10 3d..3 28384202439: sched_switch: prev_comm=rcu_preempt prev_pid=10 prev_prio=120 prev_state=D ==> next_comm=watchdog/3 next_pid=38 next_prio=120
>
> The watchdog ran, and then:
>
> [ 125.940066] watchdog-38 3d..3 28384692863: sched_switch: prev_comm=watchdog/3 prev_pid=38 prev_prio=120 prev_state=P ==> next_comm=modprobe next_pid=2848 next_prio=118
>
> Not sure what modprobe was doing, but shortly after that:
>
> [ 125.940066] modprobe-2848 3d..3 28385041749: sched_switch: prev_comm=modprobe prev_pid=2848 prev_prio=118 prev_state=R+ ==> next_comm=migration/3 next_pid=40 next_prio=0
>
> Where the migration thread took down the CPU:
>
> [ 125.940066] migratio-40 3d..3 28389148276: sched_switch: prev_comm=migration/3 prev_pid=40 prev_prio=0 prev_state=P ==> next_comm=swapper/3 next_pid=0 next_prio=120
>
> which finally did:
>
> [ 125.940066] <idle>-0 3...1 28389282142: arch_cpu_idle_dead <-cpu_startup_entry
> [ 125.940066] <idle>-0 3...1 28389282548: native_play_dead <-arch_cpu_idle_dead
> [ 125.940066] <idle>-0 3...1 28389282924: play_dead_common <-native_play_dead
> [ 125.940066] <idle>-0 3...1 28389283468: idle_task_exit <-play_dead_common
> [ 125.940066] <idle>-0 3...1 28389284644: amd_e400_remove_cpu <-play_dead_common
>
>
> CPU 3 is now offline, the rcu_preempt thread that ran on CPU 3 is still
> doing a schedule_timeout_uninterruptible() and it registered it's
> timeout to the timer base for CPU 3. You would think that it would get
> migrated right? The issue here is that the timer migration happens at
> the CPU notifier for CPU_DEAD. The problem is that the rcu notifier for
> CPU_DOWN is blocked waiting for the onoff_mutex to be released, which is
> held by the thread that just put itself into a uninterruptible sleep,
> that wont wake up until the CPU_DEAD notifier of the timer
> infrastructure is called, which wont happen until the rcu notifier
> finishes. Here's our deadlock!
This commit breaks this deadlock cycle by substituting a shorter udelay()
for the previous schedule_timeout_uninterruptible(), while at the same
time increasing the probability of the delay. This maintains the intensity
of the testing.
Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Steven Rostedt [Tue, 28 May 2013 21:32:53 +0000 (17:32 -0400)]
rcu: Don't call wakeup() with rcu_node structure ->lock held
This commit fixes a lockdep-detected deadlock by moving a wake_up()
call out from a rnp->lock critical section. Please see below for
the long version of this story.
On Tue, 2013-05-28 at 16:13 -0400, Dave Jones wrote:
rcu_start_future_gp() is called with the rnp->lock held. Then it calls
rcu_start_gp_advance, which does a wakeup.
You can't do wakeups while holding the rnp->lock, as that would mean
that you could not do a rcu_read_unlock() while holding the rq lock, or
any lock that was taken while holding the rq lock. This is because...
(See below).
perf took its own ctx->lock, which can be taken while holding the rq
lock. While holding this lock, it did a rcu_read_unlock(). The
perf_lock_task_context() basically looks like:
Now, what looks to have happened, is that we scheduled after taking that
first rcu_read_lock() but before taking the spin lock. When we scheduled
back in and took the ctx->lock, the following rcu_read_unlock()
triggered the "special" code.
The rcu_read_unlock_special() takes the rnp->lock, which gives us a
possible deadlock scenario.
This commit delays the wakeup via irq_work(), which is what
perf and ftrace use to perform wakeups in critical sections.
Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Wed, 22 May 2013 09:41:36 +0000 (02:41 -0700)]
trace: Allow idle-safe tracepoints to be called from irq
__DECLARE_TRACE_RCU() currently creates an _rcuidle() tracepoint which
may safely be invoked from what RCU considers to be an idle CPU.
However, these _rcuidle() tracepoints may -not- be invoked from the
handler of an irq taken from idle, because rcu_idle_enter() zeroes
RCU's nesting-level counter, so that the rcu_irq_exit() returning to
idle will trigger a WARN_ON_ONCE().
This commit therefore substitutes rcu_irq_enter() for rcu_idle_exit()
and rcu_irq_exit() for rcu_idle_enter() in order to make the _rcuidle()
tracepoints usable from irq handlers as well as from process context.
Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org>
Bjørn Mork [Tue, 14 May 2013 10:33:47 +0000 (03:33 -0700)]
rcu: Switch to exedited grace periods for suspend as well as hibernation
Commit 587ff2cf ("rcu: Expedite grace periods during suspend/resume")
enabled expedited grace periods for hibernation, but not for suspend.
The same issue applies to both cases, so this commit simply applies the
same logic by adding additional cases to the switch statement.
Note that this commit also switches from PM_POST_RESTORE to the
combination of PM_POST_HIBERNATION and PM_POST_SUSPEND. A separate
patch from Borislav Petkov corrects the documentation to indicate that
this is necessary.
Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
rcu: Eliminate unused APIs intended for adaptive ticks
The rcu_user_enter_after_irq() and rcu_user_exit_after_irq()
functions were intended for use by adaptive ticks, but changes
in implementation have rendered them unnecessary. This commit
therefore removes them.
Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Wed, 24 Apr 2013 00:05:42 +0000 (17:05 -0700)]
rcu: Add duplicate-callback tests to rcutorture
This commit adds a object_debug option to rcutorture to allow the
debug-object-based checks for duplicate call_rcu() invocations to
be deterministically tested.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Paul E. McKenney [Tue, 23 Apr 2013 20:20:57 +0000 (13:20 -0700)]
rcu: Make call_rcu() leak callbacks for debug-object errors
If someone does a duplicate call_rcu(), the worst thing the second
call_rcu() could do would be to actually queue the callback the second
time because doing so corrupts whatever list the callback was already
queued on. This commit therefore makes __call_rcu() check the new
return value from debug-objects and leak the callback upon error.
This commit also substitutes rcu_leak_callback() for whatever callback
function was previously in place in order to avoid freeing the callback
out from under any readers that might still be referencing it.
These changes increase the probability that the debug-objects error
messages will actually make it somewhere visible.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Paul E. McKenney [Tue, 23 Apr 2013 19:51:11 +0000 (12:51 -0700)]
debugobjects: Make debug_object_activate() return status
In order to better respond to things like duplicate invocations
of call_rcu(), RCU needs to see the status of a call to
debug_object_activate(). This would allow RCU to leak the callback in
order to avoid adding freelist-reuse mischief to the duplicate invoations.
This commit therefore makes debug_object_activate() return status,
zero for success and -EINVAL for failure.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Paul E. McKenney [Tue, 23 Apr 2013 18:31:50 +0000 (11:31 -0700)]
rcu: Simplify debug-objects fixups
The current debug-objects fixups are complex and heavyweight, and the
fixups are not complete: Even with the fixups, RCU's callback lists
can still be corrupted. This commit therefore strips the fixups down
to their minimal form, eliminating two of the three.
It would be even better if (for example) call_rcu() simply leaked
any problematic callbacks, but for that to happen, the debug-objects
system would need to inform its caller of suspicious situations.
This is the subject of a later commit in this series.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Paul E. McKenney [Mon, 22 Apr 2013 22:02:14 +0000 (15:02 -0700)]
rcu: Expedite during suspend and resume only on smallish systems
Expedited grace periods are of dubious benefit on very large systems,
so this commit restricts their automated use during suspend and resume
to systems of 256 or fewer CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CONFIG_RCU_FAST_NO_HZ can increase grace-period durations by up to
a factor of four, which can result in long suspend and resume times.
Thus, this commit temporarily switches to expedited grace periods when
suspending the box and return to normal settings when resuming.
[ paulmck: This also papers over an audio/irq bug, but hopefully that will
be fixed soon. ]
Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Thu, 18 Apr 2013 21:25:03 +0000 (14:25 -0700)]
rcu: Fix rcu_barrier() documentation
There was a time when rcu_barrier() was guaranteed to wait for at least
a grace period, but that time ended due to energy-efficiency concerns.
So now rcu_barrier() is a no-op if there are no RCU callbacks queued in
the system. This commit updates the documentation to reflect this change.
Now, rcu_barrier() often does wait for a grace period, so, one could
imagine some modification to rcu_barrier() to more efficiently handle
cases where both rcu_barrier() and a grace period are needed. But this
must wait until someone shows a real-world need for a change.
Reported-by: Bob Copeland <bob@cozybit.com> Reported-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Tue, 16 Apr 2013 14:49:22 +0000 (07:49 -0700)]
rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs
TINY_RCU's reset_cpu_stall_ticks() and check_cpu_stalls() functions
are defined unconditionally, and are empty functions if CONFIG_RCU_TRACE
is disabled (which in turns disables detection of RCU CPU stalls).
This commit saves a few lines of source code by defining these functions
only if CONFIG_RCU_TRACE=y.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Tue, 30 Apr 2013 17:48:35 +0000 (10:48 -0700)]
kthread: Add kworker kthreads to OS-jitter documentation
The kworker workqueue kthreads can also contribute to OS jitter.
The amount of jitter depends on their use, so this commit adds
documentation on avoiding OS jitter due to workqueue use.
Reported-by: Jonathan Clairembault <jonathan.clairembault@novasparks.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Mon, 13 May 2013 17:32:10 +0000 (10:32 -0700)]
nohz_full: Document additional restrictions
This commit calls out the potential for slowing the tick even when there
are multiple runnable processes per CPU, It also points out that current
mainlined version keeps the tick going on at least one CPU even when all
CPUs are otherwise idle. Finally, it notes the need for a 1-HZ tick in
order to calculate CPU load, maintain sched average, compute CFS entity
vruntime, compute avenrun, and carry out load balancing.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Thu, 11 Apr 2013 17:15:52 +0000 (10:15 -0700)]
rcu: Shrink TINY_RCU by moving exit_rcu()
Now that TINY_PREEMPT_RCU is no more, exit_rcu() is always an empty
function. But if TINY_RCU is going to have an empty function, it should
be in include/linux/rcutiny.h, where it does not bloat the kernel.
This commit therefore moves exit_rcu() out of kernel/rcupdate.c to
kernel/rcutree_plugin.h, and places a static inline empty function in
include/linux/rcutiny.h in order to shrink TINY_RCU a bit.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 27 Mar 2013 17:32:00 +0000 (10:32 -0700)]
rcu: Remove rcu_preempt_note_context_switch()
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_note_context_switch()
is now an empty function. This commit therefore eliminates it by inlining it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Mon, 15 Apr 2013 15:25:27 +0000 (08:25 -0700)]
rcu: Remove the CONFIG_TINY_RCU ifdefs in rcutiny.h
Now that CONFIG_TINY_PREEMPT_RCU is no more, this commit removes
the CONFIG_TINY_RCU ifdefs from include/linux/rcutiny.h in favor of
unconditionally compiling the CONFIG_TINY_RCU legs of those ifdefs.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Moved removal of #else to "Remove TINY_PREEMPT_RCU" as
suggested by Josh Triplett. ] Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 27 Mar 2013 17:11:15 +0000 (10:11 -0700)]
rcu: Simplify RCU_TINY RCU callback invocation
TINY_PREEMPT_RCU could use a kthread to handle RCU callback invocation,
which required an API to abstract kthread vs. softirq invocation.
Now that TINY_PREEMPT_RCU is no longer with us, this commit retires
this API in favor of direct use of the relevant softirq primitives.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 27 Mar 2013 16:11:12 +0000 (09:11 -0700)]
rcu: Remove rcu_preempt_process_callbacks()
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_process_callbacks()
is now an empty function. This commit therefore eliminates it by
inlining it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 27 Mar 2013 16:05:34 +0000 (09:05 -0700)]
rcu: Remove rcu_preempt_remove_callbacks()
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_remove_callbacks()
is now an empty function. This commit therefore eliminates it by
inlining it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 27 Mar 2013 16:02:40 +0000 (09:02 -0700)]
rcu: Remove rcu_preempt_check_callbacks()
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_check_callbacks()
is now an empty function. This commit therefore eliminates it by
inlining it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Wed, 27 Mar 2013 15:44:00 +0000 (08:44 -0700)]
rcu: Remove TINY_PREEMPT_RCU
TINY_PREEMPT_RCU adds significant code and complexity, but does not
offer commensurate benefits. People currently using TINY_PREEMPT_RCU
can get much better memory footprint with TINY_RCU, or, if they really
need preemptible RCU, they can use TREE_PREEMPT_RCU with a relatively
minor degradation in memory footprint. Please note that this move
has been widely publicized on LKML (https://lkml.org/lkml/2012/11/12/545)
and on LWN (http://lwn.net/Articles/541037/).
This commit therefore removes TINY_PREEMPT_RCU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Updated to eliminate #else in rcutiny.h as suggested by Josh ] Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 12 Mar 2013 23:54:14 +0000 (16:54 -0700)]
rcu: Remove srcu_read_lock_raw() and srcu_read_unlock_raw().
These interfaces never did get used, so this commit removes them,
their rcutorture tests, and documentation referencing them.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 30 Apr 2013 21:49:42 +0000 (14:49 -0700)]
rcu: Apply Dave Jones's NOCB Kconfig help feedback
The Kconfig help text for the RCU_NOCB_CPU_NONE, RCU_NOCB_CPU_ZERO,
and RCU_NOCB_CPU_ALL Kconfig options was unclear, so this commit
adds a bit more detail.
Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Systems with HZ=100 can have slow bootup times due to the default
three-jiffy delays between quiescent-state forcing attempts. This
commit therefore auto-tunes the RCU_JIFFIES_TILL_FORCE_QS value based
on the value of HZ. However, this would break very large systems that
require more time between quiescent-state forcing attempts. This
commit therefore also ups the default delay by one jiffy for each
256 CPUs that might be on the system (based off of nr_cpu_ids at
runtime, -not- NR_CPUS at build time).
Updated to collapse #ifdefs for RCU_JIFFIES_TILL_FORCE_QS into a
step-function definition as suggested by Josh Triplett.
Reported-by: Paul Mackerras <paulus@au1.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Paul E. McKenney [Fri, 29 Mar 2013 03:48:36 +0000 (20:48 -0700)]
rcu: Remove "Experimental" flags
After a release or two, features are no longer experimental. Therefore,
this commit removes the "Experimental" tag from them.
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 19 Mar 2013 19:38:24 +0000 (12:38 -0700)]
rcu: Move redundant call to note_gp_changes() into called function
The __rcu_process_callbacks() invokes note_gp_changes() immediately
before invoking rcu_check_quiescent_state(), which conditionally
invokes that same function. This commit therefore eliminates the
call to note_gp_changes() in __rcu_process_callbacks() in favor of
making unconditional to call from rcu_check_quiescent_state() to
note_gp_changes().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 19 Mar 2013 19:27:50 +0000 (12:27 -0700)]
rcu: Inline trivial wrapper function rcu_start_gp_per_cpu()
Given the changes that introduce note_gp_change(), rcu_start_gp_per_cpu()
is now a trivial wrapper function with only one caller. This commit
therefore inlines it into its sole call site.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 19 Mar 2013 19:21:29 +0000 (12:21 -0700)]
rcu: Eliminate check_for_new_grace_period() wrapper function
One of the calls to check_for_new_grace_period() is now redundant due to
an immediately preceding call to note_gp_changes(). Eliminating this
redundant call leaves a single caller, which is simpler if inlined.
This commit therefore eliminates the redundant call and inlines the
body of check_for_new_grace_period() into the single remaining call site.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 19 Mar 2013 18:32:11 +0000 (11:32 -0700)]
rcu: Switch callers from rcu_process_gp_end() to note_gp_changes()
Because note_gp_changes() now incorporates rcu_process_gp_end() function,
this commit switches to the former and eliminates the latter. In
addition, this commit changes external calls from __rcu_process_gp_end()
to __note_gp_changes().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 19 Mar 2013 18:10:43 +0000 (11:10 -0700)]
rcu: Rename note_new_gpnum() to note_gp_changes()
Because note_new_gpnum() now also checks for the ends of old grace periods,
this commit changes its name to note_gp_changes(). Later commits will merge
rcu_process_gp_end() into note_gp_changes().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 19 Mar 2013 17:53:14 +0000 (10:53 -0700)]
rcu: Make __note_new_gpnum() check for ends of prior grace periods
The current implementation can detect the beginning of a new grace period
before noting the end of a previous grace period. Although the current
implementation correctly handles this sort of nonsense, it would be
good to reduce RCU's state space by making such nonsense unnecessary,
which is now possible thanks to the fact that RCU's callback groups are
now numbered.
This commit therefore makes __note_new_gpnum() invoke
__rcu_process_gp_end() in order to note the ends of prior grace
periods before noting the beginnings of new grace periods.
Of course, this now means that note_new_gpnum() notes both the
beginnings and ends of grace periods, and could therefore be
used in place of rcu_process_gp_end(). But that is a job for
later commits.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Paul E. McKenney [Tue, 19 Mar 2013 17:08:37 +0000 (10:08 -0700)]
rcu: Move code to apply callback-numbering simplifications
The addition of callback numbering allows combining the detection of the
ends of old grace periods and the beginnings of new grace periods. This
commit moves code to set the stage for this combining.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Linus Torvalds [Mon, 20 May 2013 21:25:19 +0000 (14:25 -0700)]
Merge tag 'stable/for-linus-3.10-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen fixes from Konrad Rzeszutek Wilk:
- Regression fix in xen privcmd fixing a memory leak.
- Add Documentation for tmem driver.
- Simplify and remove code in the tmem driver.
- Cleanups.
* tag 'stable/for-linus-3.10-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen: Fixed assignment error in if statement
xen/xenbus: Fixed over 80 character limit issue
xen/xenbus: Fixed indentation error in switch case
xen/tmem: Don't use self[ballooning|shrinking] if frontswap is off.
xen/tmem: Remove the usage of '[no|]selfballoon' and use 'tmem.selfballooning' bool instead.
xen/tmem: Remove the usage of 'noselfshrink' and use 'tmem.selfshrink' bool instead.
xen/tmem: Remove the boot options and fold them in the tmem.X parameters.
xen/tmem: s/disable_// and change the logic.
xen/tmem: Fix compile warning.
xen/tmem: Split out the different module/boot options.
xen/tmem: Move all of the boot and module parameters to the top of the file.
xen/tmem: Cleanup. Remove the parts that say temporary.
xen/privcmd: fix condition in privcmd_close()
Linus Torvalds [Mon, 20 May 2013 18:36:52 +0000 (11:36 -0700)]
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon fixes from Guenter Roeck:
- Error path fixes for abituguru and iio_hwmon drivers.
- Drop erroneously created attributes from nct6775 driver.
- Drop redundant safety on cache lifetime for tmp401 driver.
- Add explicit maintainer for LM95234 and TMP401 drivers.
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
MAINTAINERS: Add myself as maintainer for LM95234 and TMP401 drivers
hwmon: (tmp401) Drop redundant safety on cache lifetime
hwmon: fix error return code in abituguru_probe()
hwmon: (iio_hwmon) Fix null pointer dereference
hwmon: (nct6775) Do not create non-existing attributes
hwmon: (iio_hwmon) Fix missing iio_channel_release_all call if devm_kzalloc fail
Linus Torvalds [Mon, 20 May 2013 18:36:03 +0000 (11:36 -0700)]
x86: Fix bit corruption at CPU resume time
In commit 78d77df71510 ("x86-64, init: Do not set NX bits on non-NX
capable hardware") we added the early_pmd_flags that gets the NX bit set
when a CPU supports NX. However, the new variable was marked __initdata,
because the main _use_ of this is in an __init routine.
However, the bit setting happens from secondary_startup_64(), which is
called not only at bootup, but on every secondary CPU start. Including
resuming from STR and at CPU hotplug time. So the value cannot be
__initdata.
Reported-bisected-and-tested-by: Michal Hocko <mhocko@suse.cz> Cc: stable@vger.kernel.org # v3.9 Acked-by: Peter Anvin <hpa@linux.intel.com> Cc: Fernando Luis Vázquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Mon, 20 May 2013 14:59:46 +0000 (07:59 -0700)]
Merge tag 'pinctrl-fixes-v3.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pinctrl fixes from Linus Walleij:
- Three fixes to make the boot path for device tree work properly on
the Nomadik pin controller.
- Compile warning fix for the vt8500 driver.
- Fix error path in pinctrl-single.
- Free mappings in error path of the Lantiq controller.
- Documentation fixes.
* tag 'pinctrl-fixes-v3.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl/lantiq: Free mapping configs for both pin and groups
pinctrl: single: fix error return code in pcs_parse_one_pinctrl_entry()
pinctrl: generic: Fix typos and clarify comments
pinctrl: vt8500: Fix incorrect data in WM8750 pinctrl table
pinctrl: abx500: Rejiggle platform data and DT initialisation
pinctrl: abx500: Specify failed sub-driver by ID instead of driver_data
Guenter Roeck [Mon, 20 May 2013 03:44:27 +0000 (20:44 -0700)]
MAINTAINERS: Add myself as maintainer for LM95234 and TMP401 drivers
I wrote the LM95234 driver and extended the TMP401 driver substantially,
and I have hardware to test both, so it makes sense to explicitly
maintain them.
Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Jean Delvare <khali@linux-fr.org>
Fix detection of the need to resize the dm thin metadata device.
The code incorrectly tried to extend the metadata device when it
didn't need to due to a merging error with patch 24347e9 ("dm thin:
detect metadata device resizing").
device-mapper: transaction manager: couldn't open metadata space map
device-mapper: thin metadata: tm_open_with_sm failed
device-mapper: thin: aborting transaction failed
device-mapper: thin: switching pool to failure mode
Jean Delvare [Sun, 19 May 2013 14:57:30 +0000 (16:57 +0200)]
hwmon: (tmp401) Drop redundant safety on cache lifetime
time_after (as opposed to time_after_equal) already ensures that the
cache lifetime is at least as much as requested. There is no point in
manually adding another jiffy to that value, and this can confuse the
reader into wrong interpretation.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Imre Deak <imre.deak@intel.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Linus Torvalds [Sat, 18 May 2013 18:35:28 +0000 (11:35 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"Miao Xie has been very busy, fixing races and enospc problems and many
other small but important pieces.
Alexandre Oliva discovered some problems with how our error handling
was interacting with the block layer and for now has disabled our
partial handling of sub-page writes. The real sub-page work is in a
series of patches from IBM that we still need to integrate and test.
The code Alexandre has turned off was really incomplete.
Josef has more error handling fixes and an important fix for the new
skinny extent format.
This also has my fix for the tracepoint crash from late in 3.9. It's
the first stage in a larger clean up to get rid of btrfs_bio and make
a proper bioset for all the items we need to tack into the bio. For
now the bioset only holds our mirror_num and stripe_index, but for the
next merge window I'll shuffle more in."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (25 commits)
Btrfs: use a btrfs bioset instead of abusing bio internals
Btrfs: make sure roots are assigned before freeing their nodes
Btrfs: explicitly use global_block_rsv for quota_tree
btrfs: do away with non-whole_page extent I/O
Btrfs: don't invoke btrfs_invalidate_inodes() in the spin lock context
Btrfs: remove BUG_ON() in btrfs_read_fs_tree_no_radix()
Btrfs: pause the space balance when remounting to R/O
Btrfs: fix unprotected root node of the subvolume's inode rb-tree
Btrfs: fix accessing a freed tree root
Btrfs: return errno if possible when we fail to allocate memory
Btrfs: update the global reserve if it is empty
Btrfs: don't steal the reserved space from the global reserve if their space type is different
Btrfs: optimize the error handle of use_block_rsv()
Btrfs: don't use global block reservation for inode cache truncation
Btrfs: don't abort the current transaction if there is no enough space for inode cache
Correct allowed raid levels on balance.
Btrfs: fix possible memory leak in replace_path()
Btrfs: fix possible memory leak in the find_parent_nodes()
Btrfs: don't allow device replace on RAID5/RAID6
Btrfs: handle running extent ops with skinny metadata
...
Linus Torvalds [Sat, 18 May 2013 17:54:54 +0000 (10:54 -0700)]
Merge branch 'devm_no_resource_check' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull devm usage cleanup from Wolfram Sang:
"Lately, I have been experimenting how to improve the devm interface to
make writing device drivers easier and less error prone while also
getting rid of its subtle issues. I think it has more potential but
still needs work and definately conistency, especiall in its usage.
The first thing I come up with is a low hanging fruit regarding
devm_ioremap_resouce(). This function already checks if the passed
resource is valid and gives an error message if not. So, we can
remove similar checks from the drivers and get rid of a bit of code
and a number of inconsistent error strings.
This series only removes the unneeded check iff devm_ioremap_resource
follows platform_get_resource directly. The previous version tried to
shuffle code if needed, too, what lead to an embarrasing bug. It
turned out to me that shuffling code for all cases found will make the
automated script too complex, so I am unsure if an automated cleanup
is the proper tool for this case. Removing the easy stuff seems
worthwhile to me, though.
Despite various architectures and platform dependencies, I managed to
compile test 45 out of 57 modified files locally using heuristics and
defconfigs."
Pulled because: 296 deletions, 0 additions.
* 'devm_no_resource_check' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (33 commits)
sound/soc/kirkwood: don't check resource with devm_ioremap_resource
sound/soc/fsl: don't check resource with devm_ioremap_resource
arch/mips/lantiq/xway: don't check resource with devm_ioremap_resource
arch/arm/plat-samsung: don't check resource with devm_ioremap_resource
arch/arm/mach-tegra: don't check resource with devm_ioremap_resource
drivers/watchdog: don't check resource with devm_ioremap_resource
drivers/w1/masters: don't check resource with devm_ioremap_resource
drivers/video/omap2/dss: don't check resource with devm_ioremap_resource
drivers/video/omap2: don't check resource with devm_ioremap_resource
drivers/usb/phy: don't check resource with devm_ioremap_resource
drivers/usb/host: don't check resource with devm_ioremap_resource
drivers/usb/gadget: don't check resource with devm_ioremap_resource
drivers/usb/chipidea: don't check resource with devm_ioremap_resource
drivers/thermal: don't check resource with devm_ioremap_resource
drivers/staging/nvec: don't check resource with devm_ioremap_resource
drivers/staging/dwc2: don't check resource with devm_ioremap_resource
drivers/spi: don't check resource with devm_ioremap_resource
drivers/rtc: don't check resource with devm_ioremap_resource
drivers/pwm: don't check resource with devm_ioremap_resource
drivers/pinctrl: don't check resource with devm_ioremap_resource
...
Linus Torvalds [Sat, 18 May 2013 17:46:50 +0000 (10:46 -0700)]
Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux
Pull device tree fixes from Grant Likely:
"Device tree bug fixes and documentation updates for v3.10
Nothing earth shattering here. A build failure fix, and fix for
releasing nodes and some documenation updates."
* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux:
Documentation/devicetree: make semantic of initrd-end more explicit
of/base: release the node correctly in of_parse_phandle_with_args()
of/documentation: move video device bindings to a common place
<linux/of_platform.h>: fix compilation warnings with DT disabled
Linus Torvalds [Sat, 18 May 2013 17:36:37 +0000 (10:36 -0700)]
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS fixes from Ralf Baechle:
"Patching up across the field. The reversion of the two ASID patches
is particularly important as it was breaking many platforms."
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: ralink: use the dwc2 driver for the rt305x USB controller
MIPS: Extract schedule_mfi info from __schedule
MIPS: Fix sibling call handling in get_frame_info
MIPS: MSP71xx: remove inline marking of EXPORT_SYMBOL functions
MIPS: Make virt_to_phys() work for all unmapped addresses.
MIPS: Fix build error for crash_dump.c in 3.10-rc1
MIPS: Xway: Fix clk leak
Revert "MIPS: Allow ASID size to be determined at boot time."
Revert "MIPS: microMIPS: Support dynamic ASID sizing."
Linus Torvalds [Sat, 18 May 2013 17:21:32 +0000 (10:21 -0700)]
Merge tag 'kmemleak-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64
Pull kmemleak patches from Catalin Marinas:
"Kmemleak now scans all the writable and non-executable module sections
to avoid false positives (previously it was only scanning specific
sections and missing .ref.data)."
* tag 'kmemleak-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
kmemleak: No need for scanning specific module sections
kmemleak: Scan all allocated, writeable and not executable module sections
Linus Torvalds [Sat, 18 May 2013 17:20:46 +0000 (10:20 -0700)]
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64
Pull arm64 fixes from Catalin Marinas:
"Fixes for duplicate definition of early_console, kernel/time/Kconfig
include, __flush_dcache_all() set/way computing, debug (locking, bit
testing). The of_platform_populate() was moved to an arch_init_call()
to allow subsys_init_call() drivers to probe the DT."
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
arm64: debug: fix mdscr.ss check when enabling debug exceptions
arm64: Do not source kernel/time/Kconfig explicitly
arm64: mm: Fix operands of clz in __flush_dcache_all
arm64: Invoke the of_platform_populate() at arch_initcall() level
arm64: debug: clear mdscr_el1 instead of taking the OS lock
arm64: Fix duplicate definition of early_console
Chris Mason [Fri, 17 May 2013 22:30:14 +0000 (18:30 -0400)]
Btrfs: use a btrfs bioset instead of abusing bio internals
Btrfs has been pointer tagging bi_private and using bi_bdev
to store the stripe index and mirror number of failed IOs.
As bios bubble back up through the call chain, we use these
to decide if and how to retry our IOs. They are also used
to count IO failures on a per device basis.
Recently a bio tracepoint was added lead to crashes because
we were abusing bi_bdev.
This commit adds a btrfs bioset, and creates explicit fields
for the mirror number and stripe index. The plan is to
extend this structure for all of the fields currently in
struct btrfs_bio, which will mean one less kmalloc in
our IO path.
Signed-off-by: Chris Mason <chris.mason@fusionio.com> Reported-by: Tejun Heo <tj@kernel.org>
Josef Bacik [Fri, 17 May 2013 18:06:51 +0000 (14:06 -0400)]
Btrfs: make sure roots are assigned before freeing their nodes
If we fail to load the chunk tree we'll call free_root_pointers, except we may
not have assigned the roots for the dev_root/extent_root/csum_root yet, so we
could NULL pointer deref at this point. Just add checks to make sure these
roots are set to keep us from panicing. Thanks,
projects / karo-tx-linux.git / log