Now that include/linux/kdb.h properly exports all the functions
required to dynamically add a kdb shell command, the reference to the
private kdb header can be removed.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
vfs: make no_llseek the default
vfs: don't use BKL in default_llseek
llseek: automatically add .llseek fop
libfs: use generic_file_llseek for simple_attr
mac80211: disallow seeks in minstrel debug code
lirc: make chardev nonseekable
viotape: use noop_llseek
raw: use explicit llseek file operations
ibmasmfs: use generic_file_llseek
spufs: use llseek in all file operations
arm/omap: use generic_file_llseek in iommu_debug
lkdtm: use generic_file_llseek in debugfs
net/wireless: use generic_file_llseek in debugfs
drm: use noop_llseek
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
BKL: introduce CONFIG_BKL.
dabusb: remove the BKL
sunrpc: remove the big kernel lock
init/main.c: remove BKL notations
blktrace: remove the big kernel lock
rtmutex-tester: make it build without BKL
dvb-core: kill the big kernel lock
dvb/bt8xx: kill the big kernel lock
tlclk: remove big kernel lock
fix rawctl compat ioctls breakage on amd64 and itanic
uml: kill big kernel lock
parisc: remove big kernel lock
cris: autoconvert trivial BKL users
alpha: kill big kernel lock
isapnp: BKL removal
s390/block: kill the big kernel lock
hpet: kill BKL, add compat_ioctl
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (278 commits)
arm: remove machine_desc.io_pg_offst and .phys_io
arm: use addruart macro to establish debug mappings
arm: return both physical and virtual addresses from addruart
arm/debug: consolidate addruart macros for CONFIG_DEBUG_ICEDCC
ARM: make struct machine_desc definition coherent with its comment
eukrea_mbimxsd-baseboard: Pass the correct GPIO to gpio_free
cpuimx27: fix compile when ULPI is selected
mach-pcm037_eet: fix compile errors
Fixing ethernet driver compilation error for i.MX31 ADS board
cpuimx51: update board support
mx5: add cpuimx51sd module and its baseboard
iomux-mx51: fix GPIO_1_xx 's IOMUX configuration
imx-esdhc: update devices registration
mx51: add resources for SD/MMC on i.MX51
iomux-mx51: fix SD1 and SD2's iomux configuration
clock-mx51: rename CLOCK1 to CLOCK_CCGR for better readability
clock-mx51: factorize clk_set_parent and clk_get_rate
eukrea_mbimxsd: add support for DVI displays
cpuimx25 & cpuimx35: fix OTG port registration in host mode
i.MX31 and i.MX35 : fix errate TLSbo65953 and ENGcm09472
...
The tracing per_cpu buffers were limited to 999 CPUs for a mear
savings in stack space of a char array. Up the array to 30 characters
which is more than enough to hold a 64 bit number.
Reported-by: Robin Holt <holt@sgi.com>
Suggested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
With the binding of time extends to events we no longer need to use
the macro RB_TIMESTAMPS_PER_PAGE. Remove it.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There's a condition to check if we should add a time extend or
not in the fast path. But this condition is racey (in the sense
that we can add a unnecessary time extend, but nothing that
can break anything). We later check if the time or event time
delta should be zero or have real data in it (not racey), making
this first check redundant.
This check may help save space once in a while, but really is
not worth the hassle to try to save some space that happens at
most 134 ms at a time.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When the time between two timestamps is greater than
2^27 nanosecs (~134 ms) a time extend event is added that extends
the time difference to 59 bits (~18 years). This is due to
events only having a 27 bit field to store time.
Currently this time extend is a separate event. We add it just before
the event data that is being written to the buffer. But before
the event data is committed, the event data can also be discarded (as
with the case of filters). But because the time extend has already been
committed, it will stay in the buffer.
If lots of events are being filtered and no event is being
written, then every 134ms a time extend can be added to the buffer
without any data attached. To keep from filling the entire buffer
with time extends, a time extend will never be the first event
in a page because the page timestamp can be used. Time extends can
only fill the rest of a page with some data at the beginning.
This patch binds the time extend with the data. The difference here
is that the time extend is not committed before the data is added.
Instead, when a time extend is needed, the space reserved on
the ring buffer is the time extend + the data event size. The
time extend is added to the first part of the reserved block and
the data is added to the second. The time extend event is passed
back to the reserver, but since the reserver also uses a function
to find the data portion of the reserved block, no changes to the
ring buffer interface need to be made.
When a commit is discarded, we now remove both the time extend and
the event. With this approach no more than one time extend can
be in the buffer in a row. Data must always follow a time extend.
Thanks to Mathieu Desnoyers for suggesting this idea.
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The delta between events is passed to the timestamp code by reference
and the timestamp code will reset the value. But it can be reset
from the caller. No need to pass it in by reference.
By changing the call to pass by value, lets gcc optimize the code
a bit more where it can store the delta in a register and not
worry about updating the reference.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The original code for the ring buffer had locations that modified
the timestamp and that change was used by the callers. Now,
the timestamp is not reused by the callers and there is no reason
to pass it by reference.
By changing the call to pass by value, lets gcc optimize the code
a bit more where it can store the timestamp in a register and not
worry about updating the reference.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Gcc inlines the slow path of the ring buffer write which can
hurt performance. This patch simply forces the slow path function
rb_move_tail() to always be a function.
The ring_buffer_benchmark module with reader_disabled=1 shows that
this patch changes the time to record an event from 135 ns to
132 ns. (3 ns or 2.22% improvement)
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The function start_func_tracer() was incorrectly added in the
#ifdef CONFIG_FUNCTION_TRACER condition, but is still used even
when function tracing is not enabled.
The calls to register_ftrace_function() and register_ftrace_graph()
become nops (and their arguments are even ignored), thus there is
no reason to hide start_func_tracer() when function tracing is
not enabled.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
According to Jens, this code does not need the BKL at all,
it is sufficiently serialized by bd_mutex.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Even though the parent is recorded with the normal function tracing
of the latency tracers (irqsoff and wakeup), the function graph
recording is bogus.
This is due to the function graph messing with the return stack.
The latency tracers pass in as the parent CALLER_ADDR0, which
works fine for plain function tracing. But this causes bogus output
with the graph tracer:
3) <idle>-0 | d.s3. 0.000 us | return_to_handler();
3) <idle>-0 | d.s3. 0.000 us | _raw_spin_unlock_irqrestore();
3) <idle>-0 | d.s3. 0.000 us | return_to_handler();
3) <idle>-0 | d.s3. 0.000 us | trace_hardirqs_on();
The "return_to_handle()" call is the trampoline of the
function graph tracer, and is meaningless in this context.
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The preempt and irqsoff tracers have three types of function tracers.
Normal function tracer, function graph entry, and function graph return.
Each of these use a complex dance to prevent recursion and whether
to trace the data or not (depending if interrupts are enabled or not).
This patch moves the duplicate code into a single routine, to
prevent future mistakes with modifying duplicate complex code.
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
