Impact: cleanup
Move the power tracer headers to trace/power.h to keep ftrace.h and power bits
more easy to maintain as separated topics.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rename the async_*_special() functions to async_*_domain(), which
describes the purpose of these functions much better.
[Broke up long lines to silence checkpatch]
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Impact: clean up
Fixed several typos in the comments.
Signed-off-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: clean up
Now that a generic in_nmi is available, this patch removes the
special code in the ring_buffer and implements the in_nmi generic
version instead.
With this change, I was also able to rename the "arch_ftrace_nmi_enter"
back to "ftrace_nmi_enter" and remove the code from the ring buffer.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This code adds an in_nmi() macro that uses the current tasks preempt count
to track when it is in NMI context. Other parts of the kernel can
use this to determine if the context is in NMI context or not.
This code was inspired by the -rt patch in_nmi version that was
written by Peter Zijlstra, who borrowed that code from
Mathieu Desnoyers.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
tracing_off() is the fastest way to stop recording to the ring buffers.
This may be used in places like panic and die, just before the
ftrace_dump is called.
This patch adds the appropriate CPP conditionals to make it a stub
function when the ring buffer is not configured it.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: prevent deadlock in NMI
The ring buffers are not yet totally lockless with writing to
the buffer. When a writer crosses a page, it grabs a per cpu spinlock
to protect against a reader. The spinlocks taken by a writer are not
to protect against other writers, since a writer can only write to
its own per cpu buffer. The spinlocks protect against readers that
can touch any cpu buffer. The writers are made to be reentrant
with the spinlocks disabling interrupts.
The problem arises when an NMI writes to the buffer, and that write
crosses a page boundary. If it grabs a spinlock, it can be racing
with another writer (since disabling interrupts does not protect
against NMIs) or with a reader on the same CPU. Luckily, most of the
users are not reentrant and protects against this issue. But if a
user of the ring buffer becomes reentrant (which is what the ring
buffers do allow), if the NMI also writes to the ring buffer then
we risk the chance of a deadlock.
This patch moves the ftrace_nmi_enter called by nmi_enter() to the
ring buffer code. It replaces the current ftrace_nmi_enter that is
used by arch specific code to arch_ftrace_nmi_enter and updates
the Kconfig to handle it.
When an NMI is called, it will set a per cpu variable in the ring buffer
code and will clear it when the NMI exits. If a write to the ring buffer
crosses page boundaries inside an NMI, a trylock is used on the spin
lock instead. If the spinlock fails to be acquired, then the entry
is discarded.
This bug appeared in the ftrace work in the RT tree, where event tracing
is reentrant. This workaround solved the deadlocks that appeared there.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: fix spurious BUG_ON() triggered under load
module_refcount() isn't reliable outside stop_machine(), as demonstrated
by Karsten Keil <kkeil@suse.de>, networking can trigger it under load
(an inc on one cpu and dec on another while module_refcount() is tallying
can give false results, for example).
Almost noone should be using __module_get, but that's another issue.
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With exclusive waiters, every process woken up through the wait queue must
ensure that the next waiter down the line is woken when it has finished.
Interruptible waiters don't do that when aborting due to a signal. And if
an aborting waiter is concurrently woken up through the waitqueue, noone
will ever wake up the next waiter.
This has been observed with __wait_on_bit_lock() used by
lock_page_killable(): the first contender on the queue was aborting when
the actual lock holder woke it up concurrently. The aborted contender
didn't acquire the lock and therefor never did an unlock followed by
waking up the next waiter.
Add abort_exclusive_wait() which removes the process' wait descriptor from
the waitqueue, iff still queued, or wakes up the next waiter otherwise.
It does so under the waitqueue lock. Racing with a wake up means the
aborting process is either already woken (removed from the queue) and will
wake up the next waiter, or it will remove itself from the queue and the
concurrent wake up will apply to the next waiter after it.
Use abort_exclusive_wait() in __wait_event_interruptible_exclusive() and
__wait_on_bit_lock() when they were interrupted by other means than a wake
up through the queue.
[akpm@linux-foundation.org: coding-style fixes]
Reported-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Mentored-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Chuck Lever <cel@citi.umich.edu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org> ["after some testing"]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Avoid calling copy_from/to_user() with fb_info->lock mutex held in fbmem
ioctl().
fb_mmap() is called under mm->mmap_sem (A) held, that also acquires
fb_info->lock (B); fb_ioctl() takes fb_info->lock (B) and does
copy_from/to_user() that might acquire mm->mmap_sem (A), causing a
deadlock.
NOTE: it doesn't push down the fb_info->lock in each own driver's
fb_ioctl(), so there are still potential deadlocks elsewhere.
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The swap() macro is accidentally retuning the value of its first argument.
Change it into a doesn't-return-anything macro before someone goes and
relies upon this behaviour.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wu Fengguang <wfg@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes the ROM reading code return an error to user space if
the size of the ROM read is equal to 0.
The patch also emits a warnings if the contents of the ROM are invalid,
and documents the effects of the "enable" file on ROM reading.
Signed-off-by: Timothy S. Nelson <wayland@wayland.id.au>
Acked-by: Alex Villacis-Lasso <a_villacis@palosanto.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Add kernel-doc notation for @lock:
include/linux/sched.h:457: No description found for parameter 'lock'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
3Gbps is often much more prone to transmission failures. It's usually
okay to let EH handle speed down after transmission failures but some
WD My Book drives completely shutdown after certain transmission
failures and after it only power cycling can revive them. Combined
with the fact that external drives often end up with cable assembly
which is longer than usual and more likely to have intervening gender,
this makes these drives very likely to shutdown under certain
configurations virtually rendering them unusable.
This patch implements HOARKGE_1_5_GBPS and applies it to WD My Book
such that 1.5Gbps is forced once the device is identified.
Please take a look at the following bz for related reports.
http://bugzilla.kernel.org/show_bug.cgi?id=9913
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
dev->ering used to be cleared together with the rest of ata_device in
ata_dev_init() which is called whenever a probing event occurs.
dev->ering is about to be used to track probing failures so it needs
to remain persistent over multiple porbing events. This patch
achieves this by doing the following.
* Instead of CLEAR_OFFSET, define CLEAR_BEGIN and CLEAR_END and only
clear between BEGIN and END. ering is moved after END. The split
of persistent area is to allow hotter items remain at the head.
* ering is explicitly cleared on ata_dev_disable() and when device
attach succeeds. So, ering is persistent throug a device's life
time (unless explicitly cleared of course) and also through periods
inbetween disablement of an attached device and successful detection
of the next one.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
When checking for the CFA feature set support, ata_id_is_cfa() tests bit 2 in
word 82 of the identify data instead the word 83; it also checks the ATA/PI
version support in the word 80 (which the CompactFlash specifications have as
reserved), this having no slightest chance to work on the modern CF cards that
don't have 0x848A in the word 0...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Current refcounting for modules (done if CONFIG_MODULE_UNLOAD=y) is
using a lot of memory.
Each 'struct module' contains an [NR_CPUS] array of full cache lines.
This patch uses existing infrastructure (percpu_modalloc() &
percpu_modfree()) to allocate percpu space for the refcount storage.
Instead of wasting NR_CPUS*128 bytes (on i386), we now use
nr_cpu_ids*sizeof(local_t) bytes.
On a typical distro, where NR_CPUS=8, shiping 2000 modules, we reduce
size of module files by about 2 Mbytes. (1Kb per module)
Instead of having all refcounters in the same memory node - with TLB misses
because of vmalloc() - this new implementation permits to have better
NUMA properties, since each CPU will use storage on its preferred node,
thanks to percpu storage.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported by Andrew Walrond <andrew@walrond.org>
Changeset c19e654ddb
("gre: Add netlink interface") added an include
of linux/ip.h to linux/if_tunnel.h
We can't really let that get exposed to userspace
because this conflicts with types defined in netinet/ip.h
which userland is almost certainly going to have included
either explicitly or implicitly.
So guard this include with a __KERNEL__ ifdef.
Signed-off-by: David S. Miller <davem@davemloft.net>
bvec_kmap_irq() and bvec_kunmap_irq() comments say they MUST be inlined,
so mark them as __always_inline.
Signed-off-by: Alberto Bertogli <albertito@blitiri.com.ar>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The comment says "remember to add offset!", but the function already adds
it.
Signed-off-by: Alberto Bertogli <albertito@blitiri.com.ar>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Impact: fix CPU hotplug hang on Power6 testbox
On architectures that support offlining all cpus (at least powerpc/pseries),
hot-unpluging the tick_do_timer_cpu can result in a system hang.
This comes from the fact that if the cpu going down happens to be the
cpu doing the tick, then as the tick_do_timer_cpu handover happens after the
cpu is dead (via the CPU_DEAD notification), we're left without ticks,
jiffies are frozen and any task relying on timers (msleep, ...) is stuck.
That's particularly the case for the cpu looping in __cpu_die() waiting
for the dying cpu to be dead.
This patch addresses this by having the tick_do_timer_cpu handover happen
earlier during the CPU_DYING notification. For this, a new clockevent
notification type is introduced (CLOCK_EVT_NOTIFY_CPU_DYING) which is triggered
in hrtimer_cpu_notify().
Signed-off-by: Sebastien Dugue <sebastien.dugue@bull.net>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix the following 'make headers_check' warning:
usr/include/linux/rtnetlink.h:328: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/nubus.h:232: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/virtio_net.h:28: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/virtio_console.h:15: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/virtio_blk.h:21: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/videodev.h:53: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/video_encoder.h:5: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/video_decoder.h:7: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/taskstats.h:44: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/synclink.h:209: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warnings:
usr/include/linux/sound.h:33: extern's make no sense in userspace
usr/include/linux/sound.h:34: extern's make no sense in userspace
usr/include/linux/sound.h:35: extern's make no sense in userspace
usr/include/linux/sound.h:36: extern's make no sense in userspace
usr/include/linux/sound.h:37: extern's make no sense in userspace
usr/include/linux/sound.h:39: extern's make no sense in userspace
usr/include/linux/sound.h:40: extern's make no sense in userspace
usr/include/linux/sound.h:41: extern's make no sense in userspace
usr/include/linux/sound.h:42: extern's make no sense in userspace
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/signalfd.h:19: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/random.h:39: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/ppp_defs.h:50: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/pkt_sched.h:32: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
linux/pkt_cls.h:122: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/phonet.h:50: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/nfs_idmap.h:55: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/neighbour.h:8: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/msdos_fs.h💯 found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/minix_fs.h:34: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/irda.h:127: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/ipx.h:13: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/ipv6_route.h:42: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/ipv6.h:26: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
include/linux/ip6_tunnel.h:21: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
fix the following 'make headers_check' warning:
usr/include/linux/inet_diag.h:16: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Frederic Weisbecker