This patch adds back the sysctl ftrace_enabled. This time it is
defaulted to on, if DYNAMIC_FTRACE is configured. When ftrace_enabled
is disabled, the ftrace function is set to the stub return.
If DYNAMIC_FTRACE is also configured, on ftrace_enabled = 0,
the registered ftrace functions will all be set to jmps, but no more
new calls to ftrace recording (used to find the ftrace calling sites)
will be called.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds a feature to dynamically replace the ftrace code
with the jmps to allow a kernel with ftrace configured to run
as fast as it can without it configured.
The way this works, is on bootup (if ftrace is enabled), a ftrace
function is registered to record the instruction pointer of all
places that call the function.
Later, if there's still any code to patch, a kthread is awoken
(rate limited to at most once a second) that performs a stop_machine,
and replaces all the code that was called with a jmp over the call
to ftrace. It only replaces what was found the previous time. Typically
the system reaches equilibrium quickly after bootup and there's no code
patching needed at all.
e.g.
call ftrace /* 5 bytes */
is replaced with
jmp 3f /* jmp is 2 bytes and we jump 3 forward */
3:
When we want to enable ftrace for function tracing, the IP recording
is removed, and stop_machine is called again to replace all the locations
of that were recorded back to the call of ftrace. When it is disabled,
we replace the code back to the jmp.
Allocation is done by the kthread. If the ftrace recording function is
called, and we don't have any record slots available, then we simply
skip that call. Once a second a new page (if needed) is allocated for
recording new ftrace function calls. A large batch is allocated at
boot up to get most of the calls there.
Because we do this via stop_machine, we don't have to worry about another
CPU executing a ftrace call as we modify it. But we do need to worry
about NMI's so all functions that might be called via nmi must be
annotated with notrace_nmi. When this code is configured in, the NMI code
will not call notrace.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add preempt off timings. A lot of kernel core code is taken from the RT patch
latency trace that was written by Ingo Molnar.
This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers
Now instead of just tracing irqs off, preemption off can be selected
to be recorded.
When this is selected, it shares the same files as irqs off timings.
One can either trace preemption off, irqs off, or one or the other off.
By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording
of preempt off only is performed. "irqsoff" will only record the time
irqs are disabled, but "preemptirqsoff" will take the total time irqs
or preemption are disabled. Runtime switching of these options is now
supported by simpling echoing in the appropriate trace name into
/debugfs/tracing/current_tracer.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If CONFIG_FTRACE is selected and /proc/sys/kernel/ftrace_enabled is
set to a non-zero value the ftrace routine will be called everytime
we enter a kernel function that is not marked with the "notrace"
attribute.
The ftrace routine will then call a registered function if a function
happens to be registered.
[ This code has been highly hacked by Steven Rostedt and Ingo Molnar,
so don't blame Arnaldo for all of this ;-) ]
Update:
It is now possible to register more than one ftrace function.
If only one ftrace function is registered, that will be the
function that ftrace calls directly. If more than one function
is registered, then ftrace will call a function that will loop
through the functions to call.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
notrace signals that a function should not be traced. Most of the
time this is used by tracers to annotate code that cannot be
traced - it's in a volatile state (such as in user vdso context
or NMI context) or it's in the tracer internals.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The tracer may need to call preempt_enable and disable functions
for time keeping and such. The trace gets ugly when we see these
functions show up for all traces. To make the output cleaner
this patch adds preempt_enable_notrace and preempt_disable_notrace
to be used by tracer (and debugging) functions.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The tracer wants to be able to convert the state number
into a user visible character. This patch pulls that conversion
string out the scheduler into the header. This way if it were to
ever change, other parts of the kernel will know.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
add 3 lightweight callbacks to the tracer backend.
zero impact if tracing is turned off.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
net: The world is not perfect patch.
tcp: Make prior_ssthresh a u32
xfrm_user: Remove zero length key checks.
net/ipv4/arp.c: Use common hex_asc helpers
cassini: Only use chip checksum for ipv4 packets.
tcp: TCP connection times out if ICMP frag needed is delayed
netfilter: Move linux/types.h inclusions outside of #ifdef __KERNEL__
af_key: Fix selector family initialization.
libertas: Fix ethtool statistics
mac80211: fix NULL pointer dereference in ieee80211_compatible_rates
mac80211: don't claim iwspy support
orinoco_cs: add ID for SpeedStream wireless adapters
hostap_cs: add ID for Conceptronic CON11CPro
rtl8187: resource leak in error case
ath5k: Fix loop variable initializations
If previous window was above representable values of u16,
strange things will happen if undo with the truncated value
is called for. Alternatively, this could be fixed by some
max trickery but that would limit undoing high-speed undos.
Adds 16-bit hole but there isn't anything to fill it with.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Greg Steuck <greg@nest.cx> points out that some of the netfilter
headers can't be used in userspace without including linux/types.h
first. The headers include their own linux/types.h include statements,
these are stripped by make headers-install because they are inside
#ifdef __KERNEL__ however. Move them out to fix this.
Reported and Tested by Greg Steuck.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'for-2.6.26' of git://linux-nfs.org/~bfields/linux: (25 commits)
svcrdma: Verify read-list fits within RPCSVC_MAXPAGES
svcrdma: Change svc_rdma_send_error return type to void
svcrdma: Copy transport address and arm CQ before calling rdma_accept
svcrdma: Set rqstp transport address in rdma_read_complete function
svcrdma: Use ib verbs version of dma_unmap
svcrdma: Cleanup queued, but unprocessed I/O in svc_rdma_free
svcrdma: Move the QP and cm_id destruction to svc_rdma_free
svcrdma: Add reference for each SQ/RQ WR
svcrdma: Move destroy to kernel thread
svcrdma: Shrink scope of spinlock on RQ CQ
svcrdma: Use standard Linux lists for context cache
svcrdma: Simplify RDMA_READ deferral buffer management
svcrdma: Remove unused READ_DONE context flags bit
svcrdma: Return error from rdma_read_xdr so caller knows to free context
svcrdma: Fix error handling during listening endpoint creation
svcrdma: Free context on post_recv error in send_reply
svcrdma: Free context on ib_post_recv error
svcrdma: Add put of connection ESTABLISHED reference in rdma_cma_handler
svcrdma: Fix return value in svc_rdma_send
svcrdma: Fix race with dto_tasklet in svc_rdma_send
...
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
USB: CDC WDM driver
USB: ehci-orion: the Orion EHCI root hub does have a Transaction Translator
USB: serial: ch341: New VID/PID for CH341 USB-serial
USB: build fix
USB: pxa27x_udc - Fix Oops
USB: OPTION: fix name of Onda MSA501HS HSDPA modem
USB: add TELIT HDSPA UC864-E modem to option driver
usb-serial: Use ftdi_sio driver for RATOC REX-USB60F
Propagate feature bits from the NETDEV_FEAT_CHANGE notifier. For now
only TSO is propagated for devices that announce their ability to
support TSO in combination with VLAN accel by setting the NETIF_F_VLAN_TSO
flag.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
We want to have the drvdata field set properly when creating the device
as sysfs callbacks can assume it is present and it can race the later
setting of this field.
So, create two new functions, deviec_create_vargs() and
device_create_drvdata() that take this new field.
device_create_drvdata() will go away in 2.6.27 as the drvdata field will
just be moved to the device_create() call as it should be.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch removes CVS keywords that weren't updated for a long time
from comments.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Since 2.6.25 the HID_QUIRK_APPLE_HAS_FN quirk is enabled even for
non-laptop Apple keyboards of the Aluminium series. The USB version of
these don't need Numlock emulation, like the laptop (and Aluminium
Wireless) do, as they have a proper keypad.
This patch splits the Numlock emulation for Apple keyboards in a
different quirk flag, so that it can be enabled for all the keyboards
but the Aluminium USB ones.
If the Numlock emulation is enabled for Aluminium USB keyboards, the
JKL and UIO keys become the numeric pad, and the rest of the keyboard
is disabled, included the key used to disable Numlock.
Additionally, these keyboard should not have a Numlock at all, as the
Numlock key is instead replaced by the 'Clear' key as usual for Apple
USB keyboards.
Signed-off-by: Diego 'Flameeyes' Petteno <flameeyes@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
[PATCH] return to old errno choice in mkdir() et.al.
[Patch] fs/binfmt_elf.c: fix wrong return values
[PATCH] get rid of leak in compat_execve()
[Patch] fs/binfmt_elf.c: fix a wrong free
[PATCH] avoid multiplication overflows and signedness issues for max_fds
[PATCH] dup_fd() part 4 - race fix
[PATCH] dup_fd() - part 3
[PATCH] dup_fd() part 2
[PATCH] dup_fd() fixes, part 1
[PATCH] take init_files to fs/file.c
I was hoping ATA_HORKAGE_NODMA | ATA_HORKAGE_SKIP_PM could keep it
happy but no even this doesn't work under certain configurations and
it's not like we can do anything useful with the cofig device anyway.
Replace ATA_HORKAGE_SKIP_PM with ATA_HORKAGE_DISABLE and use it for
the config device. This makes the device completely ignored by
libata.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
