When more than one header is included under CREATE_TRACE_POINTS
the DECLARE_TRACE() macro is not defined back to its original meaning
and the second include will fail to initialize the TRACE_EVENT()
and DECLARE_TRACE() correctly.
To fix this the tracepoint.h file moves the define of DECLARE_TRACE()
out of the #ifdef _LINUX_TRACEPOINT_H protection (just like the
define of the TRACE_EVENT()). This way the define_trace.h will undef
the DECLARE_TRACE() at the end and allow new headers to start
from scratch.
This patch also requires fixing the include/events/napi.h
It currently uses DECLARE_TRACE() and should be converted to a TRACE_EVENT()
format. But I'll leave that change to the authors of that file.
But since the napi.h file depends on using the CREATE_TRACE_POINTS
and does not define its own DEFINE_TRACE() it must use the define_trace.h
method instead.
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ftrace.h file contains several functions as macros when the
functions are disabled due to config options. This patch converts
most of them to static inlines.
There are two exceptions:
register_ftrace_function() and unregister_ftrace_function()
This is because their parameter "ops" must not be evaluated since
code using the function is allowed to #ifdef out the creation of
the parameter.
This also fixes an error caused by recent changes:
kernel/trace/trace_irqsoff.c: In function 'start_irqsoff_tracer':
kernel/trace/trace_irqsoff.c:571: error: expected expression before 'do'
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When performing a non-consuming read, a synchronize_sched() is
performed once for every cpu which is actively tracing.
This is very expensive, and can make it take several seconds to open
up the 'trace' file with lots of cpus.
Only one synchronize_sched() call is actually necessary. What is
desired is for all cpus to see the disabling state change. So we
transform the existing sequence:
for_each_cpu() {
ring_buffer_read_start();
}
where each ring_buffer_start() call performs a synchronize_sched(),
into the following:
for_each_cpu() {
ring_buffer_read_prepare();
}
ring_buffer_read_prepare_sync();
for_each_cpu() {
ring_buffer_read_start();
}
wherein only the single ring_buffer_read_prepare_sync() call needs to
do the synchronize_sched().
The first phase, via ring_buffer_read_prepare(), allocates the 'iter'
memory and increments ->record_disabled.
In the second phase, ring_buffer_read_prepare_sync() makes sure this
->record_disabled state is visible fully to all cpus.
And in the final third phase, the ring_buffer_read_start() calls reset
the 'iter' objects allocated in the first phase since we now know that
none of the cpus are adding trace entries any more.
This makes openning the 'trace' file nearly instantaneous on a
sparc64 Niagara2 box with 128 cpus tracing.
Signed-off-by: David S. Miller <davem@davemloft.net>
LKML-Reference: <20100420.154711.11246950.davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ftrace_dump_on_oops kernel parameter, sysctl and sysrq let one
dump every cpu buffers when an oops or panic happens.
It's nice when you have few cpus but it may take ages if have many,
plus you miss the real origin of the problem in all the cpu traces.
Sometimes, all you need is to dump the cpu buffer that triggered the
opps, most of the time it is our main interest.
This patch modifies ftrace_dump_on_oops to handle this choice.
The ftrace_dump_on_oops kernel parameter, when it comes alone, has
the same behaviour than before. But ftrace_dump_on_oops=orig_cpu
will only dump the buffer of the cpu that oops'ed.
Similarly, sysctl kernel.ftrace_dump_on_oops=1 and
echo 1 > /proc/sys/kernel/ftrace_dump_on_oops keep their previous
behaviour. But setting 2 jumps into cpu origin dump mode.
v2: Fix double setup
v3: Fix spelling issues reported by Randy Dunlap
v4: Also update __ftrace_dump in the selftests
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: Make RCU lockdep check the lockdep_recursion variable
rcu: Update docs for rcu_access_pointer and rcu_dereference_protected
rcu: Better explain the condition parameter of rcu_dereference_check()
rcu: Add rcu_access_pointer and rcu_dereference_protected
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm/radeon/kms: add FireMV 2400 PCI ID.
drm/radeon/kms: allow R500 regs VAP_ALT_NUM_VERTICES and VAP_INDEX_OFFSET
drivers/gpu/radeon: Add MSPOS regs to safe list.
drm/radeon/kms: disable the tv encoder when tv/cv is not in use
drm/radeon/kms: adjust pll settings for tv
drm/radeon/kms: fix tv dac conflict resolver
drm/radeon/kms/evergreen: don't enable hdmi audio stuff
drm/radeon/kms/atom: fix dual-link DVI on DCE3.2/4.0
drm/radeon/kms: fix rs600 tlb flush
drm/radeon/kms: print GPU family and device id when loading
drm/radeon/kms: fix calculation of mipmapped 3D texture sizes
drm/radeon/kms: only change mode when coherent value changes.
drm/radeon/kms: more atom parser fixes (v2)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: wacom - switch mode upon system resume
Revert "Input: wacom - merge out and in prox events"
Input: matrix_keypad - allow platform to disable key autorepeat
Input: ALPS - add signature for HP Pavilion dm3 laptops
Input: i8042 - spelling fix
Input: sparse-keymap - implement safer freeing of the keymap
Input: update the status of the Multitouch X driver project
Input: clarify the no-finger event in multitouch protocol
Input: bcm5974 - retract efi-broken suspend_resume
Input: sparse-keymap - free the right keymap on error
Among else, this allows projects like libdc1394 to carry copies of the
ABI related header files without them or distributors having to worry
about effects on the project's overall license terms. Switch to MIT
license as suggested by Kristian. Also update the year in the
copyright statement according to source history.
Cc: Jay Fenlason <fenlason@redhat.com>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
This patch adds variants of rcu_dereference() that handle
situations where the RCU-protected data structure cannot change,
perhaps due to our holding the update-side lock, or where the
RCU-protected pointer is only to be fetched, not dereferenced.
These are needed due to some performance concerns with using
rcu_dereference() where it is not required, aside from the need
for lockdep/sparse checking.
The new rcu_access_pointer() primitive is for the case where the
pointer is be fetch and not dereferenced. This primitive may be
used without protection, RCU or otherwise, due to the fact that
it uses ACCESS_ONCE().
The new rcu_dereference_protected() primitive is for the case
where updates are prevented, for example, due to holding the
update-side lock. This primitive does neither ACCESS_ONCE() nor
smp_read_barrier_depends(), so can only be used when updates are
somehow prevented.
Suggested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
Cc: eric.dumazet@gmail.com
LKML-Reference: <1270852752-25278-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFSv4: fix delegated locking
NFS: Ensure that the WRITE and COMMIT RPC calls are always uninterruptible
NFS: Fix a race with the new commit code
NFS: Ensure that writeback_single_inode() calls write_inode() when syncing
NFS: Fix the mode calculation in nfs_find_open_context
NFSv4: Fall back to ordinary lookup if nfs4_atomic_open() returns EISDIR
Arnaud Giersch reports that NFSv4 locking is broken when we hold a
delegation since commit 8e469ebd6d (NFSv4:
Don't allow posix locking against servers that don't support it).
According to Arnaud, the lock succeeds the first time he opens the file
(since we cannot do a delegated open) but then fails after we start using
delegated opens.
The following patch fixes it by ensuring that locking behaviour is
governed by a per-filesystem capability flag that is initially set, but
gets cleared if the server ever returns an OPEN without the
NFS4_OPEN_RESULT_LOCKTYPE_POSIX flag being set.
Reported-by: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits)
cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch
loop: Update mtime when writing using aops
block: expose the statistics in blkio.time and blkio.sectors for the root cgroup
backing-dev: Handle class_create() failure
Block: Fix block/elevator.c elevator_get() off-by-one error
drbd: lc_element_by_index() never returns NULL
cciss: unlock on error path
cfq-iosched: Do not merge queues of BE and IDLE classes
cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging
i2o: Remove the dangerous kobj_to_i2o_device macro
block: remove 16 bytes of padding from struct request on 64bits
cfq-iosched: fix a kbuild regression
block: make CONFIG_BLK_CGROUP visible
Remove GENHD_FL_DRIVERFS
block: Export max number of segments and max segment size in sysfs
block: Finalize conversion of block limits functions
block: Fix overrun in lcm() and move it to lib
vfs: improve writeback_inodes_wb()
paride: fix off-by-one test
drbd: fix al-to-on-disk-bitmap for 4k logical_block_size
...
radix_tree_tag_get() is not safe to use concurrently with radix_tree_tag_set()
or radix_tree_tag_clear(). The problem is that the double tag_get() in
radix_tree_tag_get():
if (!tag_get(node, tag, offset))
saw_unset_tag = 1;
if (height == 1) {
int ret = tag_get(node, tag, offset);
may see the value change due to the action of set/clear. RCU is no protection
against this as no pointers are being changed, no nodes are being replaced
according to a COW protocol - set/clear alter the node directly.
The documentation in linux/radix-tree.h, however, says that
radix_tree_tag_get() is an exception to the rule that "any function modifying
the tree or tags (...) must exclude other modifications, and exclude any
functions reading the tree".
The problem is that the next statement in radix_tree_tag_get() checks that the
tag doesn't vary over time:
BUG_ON(ret && saw_unset_tag);
This has been seen happening in FS-Cache:
https://www.redhat.com/archives/linux-cachefs/2010-April/msg00013.html
To this end, remove the BUG_ON() from radix_tree_tag_get() and note in various
comments that the value of the tag may change whilst the RCU read lock is held,
and thus that the return value of radix_tree_tag_get() may not be relied upon
unless radix_tree_tag_set/clear() and radix_tree_delete() are excluded from
running concurrently with it.
Reported-by: Romain DEGEZ <romain.degez@smartjog.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most drives from Seagate, Hitachi, and possibly other brands,
do not allow LBA28 access to sector number 0x0fffffff (2^28 - 1).
So instead use LBA48 for such accesses.
This bug could bite a lot of systems, especially when the user has
taken care to align partitions to 4KB boundaries. On misaligned systems,
it is less likely to be encountered, since a 4KB read would end at
0x10000000 rather than at 0x0fffffff.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Steven Rostedt
David Miller
Jiri Olsa
Ingo Molnar
Frederic Weisbecker
Linus Torvalds
Dave Airlie
Paul E. McKenney
Stefan Richter
David Howells
Trond Myklebust
Clemens Ladisch
Pekka Enberg
Mark Lord