This patch adds the latency tracer infrastructure. This patch
does not add anything that will select and turn it on, but will
be used by later patches.
If it were to be compiled, it would add the following files
to the debugfs:
The root tracing directory:
/debugfs/tracing/
This patch also adds the following files:
available_tracers
list of available tracers. Currently no tracers are
available. Looking into this file only shows
"none" which is used to unregister all tracers.
current_tracer
The trace that is currently active. Empty on start up.
To switch to a tracer simply echo one of the tracers that
are listed in available_tracers:
example: (used with later patches)
echo function > /debugfs/tracing/current_tracer
To disable the tracer:
echo disable > /debugfs/tracing/current_tracer
tracing_enabled
echoing "1" into this file starts the ftrace function tracing
(if sysctl kernel.ftrace_enabled=1)
echoing "0" turns it off.
latency_trace
This file is readonly and holds the result of the trace.
trace
This file outputs a easier to read version of the trace.
iter_ctrl
Controls the way the output of traces look.
So far there's two controls:
echoing in "symonly" will only show the kallsyms variables
without the addresses (if kallsyms was configured)
echoing in "verbose" will change the output to show
a lot more data, but not very easy to understand by
humans.
echoing in "nosymonly" turns off symonly.
echoing in "noverbose" turns off verbose.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
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>
Mark with "notrace" functions in core code that should not be
traced. The "notrace" attribute will prevent gcc from adding
a call to ftrace on the annotated funtions.
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>
Add the notrace annotations to the vsyscall functions - there we are
not in kernel context yet, so the tracer function cannot (and must not)
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>
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
When we fully commit to returning back to kernel mode from
a trap, zero out the regs->magic value to prevent false
positives during stack backtraces.
Signed-off-by: David S. Miller <davem@davemloft.net>
The offset to the pt_regs area was wrong, so we weren't
looking at the right location for the magic cookie.
A trap frame is composed of a "struct sparc_stackf" then
a "struct pt_regs", the code was using "struct reg_window"
instead of "struct sparc_stackf".
Signed-off-by: David S. Miller <davem@davemloft.net>
Because of the silly way I set up the initial stack for
new kernel threads, there is a loop at the top of the
stack.
To fix this, properly add another stack frame that is copied
from the parent and terminate it in the child by setting
the frame pointer in that frame to zero.
Signed-off-by: David S. Miller <davem@davemloft.net>
Unless there will be any objection here, I suggest consider the
following patch which simply removes the code for the
-DI_WISH_WORLD_WERE_PERFECT in the three methods which use it.
The compilation errors we get when using -DI_WISH_WORLD_WERE_PERFECT
show that this code was not built and not used for really a long time.
Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
The crypto layer will determine whether that is valid
or not.
Suggested by Herbert Xu, based upon a report and patch
by Martin Willi.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Here the local hexbuf is a duplicate of global const char hex_asc from
lib/hexdump.c, except the hex letters' cases:
const char hexbuf[] = "0123456789ABCDEF";
const char hex_asc[] = "0123456789abcdef";
and here to print HW addresses, the hex cases are not significant.
Thanks to Harvey Harrison to introduce the hex_asc_hi/hex_asc_lo helpers.
Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
According to David Monro, at least with Natsemi Saturn chips the
cassini driver has some trouble with ipv6 checksums.
Until we have more information about what's going on here, only
use the chip checksums for ipv4.
This workaround was suggested and tested by David.
Update version and release date.
Signed-off-by: David S. Miller <davem@davemloft.net>
Whether we sidestep it in init/main.c or not, such situations
will arise again; compiler does generate calls of strcat()
on optimizations, so we really ought to have an out-of-line
version...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
... and we have few enough places using the latter to make it
simpler to do search and replace...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memcpy() from userland pointer is a Bad Thing(tm)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fallout from commit 46d7b522eb ("uml: move
hppfs_kern.c to hppfs.c")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We want sys/ptrace.h before any includes of linux/ptrace.h and
asm/user.h pulls the latter.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We are seeing an issue with TCP in handling an ICMP frag needed
message that is received after net.ipv4.tcp_retries1 retransmits.
The default value of retries1 is 3. So if the path mtu changes
and ICMP frag needed is lost for the first 3 retransmits or if
it gets delayed until 3 retransmits are done, TCP doesn't update
MSS correctly and continues to retransmit the orginal message
until it timesout after tcp_retries2 retransmits.
I am seeing this issue even with the latest 2.6.25.4 kernel.
In tcp_retransmit_timer(), when retransmits counter exceeds
tcp_retries1 value, the dst cache entry of the socket is reset.
At this time, if we receive an ICMP frag needed message, the
dst entry gets updated with the new MTU, but the TCP sockets
dst_cache entry remains NULL.
So the next time when we try to retransmit after the ICMP frag
needed is received, tcp_retransmit_skb() gets called. Here the
cur_mss value is calculated at the start of the routine with
a NULL sk_dst_cache. Instead we should call tcp_current_mss after
the rebuild_header that caches the dst entry with the updated mtu.
Also the rebuild_header should be called before tcp_fragment
so that skb is fragmented if the mss goes down.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
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>
This propagates the xfrm_user fix made in commit
bcf0dda8d2 ("[XFRM]: xfrm_user: fix
selector family initialization")
Based upon a bug report from, and tested by, Alan Swanson.
Signed-off-by: Kazunori MIYAZAWA <kazunori@miyazawa.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: (21 commits)
[CIFS] Remove debug statement
Fix possible access to undefined memory region.
[CIFS] Enable DFS support for Windows query path info
[CIFS] Enable DFS support for Unix query path info
[CIFS] add missing seq_printf to cifs_show_options for hard mount option
[CIFS] add more complete mount options to cifs_show_options
[CIFS] Add missing defines for DFS
CIFSGetDFSRefer cleanup + dfs_referral_level_3 fixed to conform REFERRAL_V3 the MS-DFSC spec.
Fixed DFS code to work with new 'build_path_from_dentry', that returns full path if share in the dfs, now.
[CIFS] enable parsing for transport encryption mount parm
[CIFS] Finishup DFS code
[CIFS] BKL-removal: convert CIFS over to unlocked_ioctl
[CIFS] suppress duplicate warning
[CIFS] Fix paths when share is in DFS to include proper prefix
add function to convert access flags to legacy open mode
clarify return value of cifs_convert_flags()
[CIFS] don't explicitly do a FindClose on rewind when directory search has ended
[CIFS] cleanup old checkpatch warnings
[CIFS] CIFSSMBPosixLock should return -EINVAL on error
fix memory leak in CIFSFindNext
...
Steven Rostedt