Change the time resolution for initcall_debug to microseconds, from
milliseconds. This is handy to determine which initcalls you want to work
on for faster booting.
One one of my test machines, over 90% of the initcalls are less than a
millisecond and (without this patch) these are all reported as 0 msecs.
Working on the 900 us ones is more important than the 4 us ones.
With 'quiet' on the kernel command line, this adds no significant overhead
to kernel boot time.
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
At this time, only built-in initcalls interest us.
We can't really produce a relevant graph if we include
the modules initcall too.
I had good results after this patch (see svg in attachment).
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Including <linux/ktime.h> eliminates the following error:
include/linux/ftrace.h:220: error: expected specifier-qualifier-list
before 'ktime_t'
Signed-off-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix:
In file included from kernel/sysctl.c:52:
include/linux/ftrace.h:217: error: 'KSYM_NAME_LEN' undeclared here (not in a function)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
After some initcall traces, some initcall names may be inconsistent.
That's because these functions will disappear from the .init section
and also their name from the symbols table.
So we have to copy the name of the function in a buffer large enough
during the trace appending. It is not costly for the ring_buffer because
the number of initcall entries is commonly not really large.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change the boot tracer printing to make it parsable for
the scripts/bootgraph.pl script.
We have now to output two lines for each initcall, according to the
printk in do_one_initcall() in init/main.c
We need now the call's time and the return's time.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The old "lock always" scheme had issues with lockdep, and was not very
efficient anyways.
This patch does a new design to be partially lockless on writes.
Writes will add new entries to the per cpu pages by simply disabling
interrupts. When a write needs to go to another page than it will
grab the lock.
A new "read page" has been added so that the reader can pull out a page
from the ring buffer to read without worrying about the writer writing over
it. This allows us to not take the lock for all reads. The lock is
now only taken when a read needs to go to a new page.
This is far from lockless, and interrupts still need to be disabled,
but it is a step towards a more lockless solution, and it also
solves a lot of the issues that were noticed by the first conversion
of ftrace to the ring buffers.
Note: the ring_buffer_{un}lock API has been removed.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This is a unified tracing buffer that implements a ring buffer that
hopefully everyone will eventually be able to use.
The events recorded into the buffer have the following structure:
struct ring_buffer_event {
u32 type:2, len:3, time_delta:27;
u32 array[];
};
The minimum size of an event is 8 bytes. All events are 4 byte
aligned inside the buffer.
There are 4 types (all internal use for the ring buffer, only
the data type is exported to the interface users).
RINGBUF_TYPE_PADDING: this type is used to note extra space at the end
of a buffer page.
RINGBUF_TYPE_TIME_EXTENT: This type is used when the time between events
is greater than the 27 bit delta can hold. We add another
32 bits, and record that in its own event (8 byte size).
RINGBUF_TYPE_TIME_STAMP: (Not implemented yet). This will hold data to
help keep the buffer timestamps in sync.
RINGBUF_TYPE_DATA: The event actually holds user data.
The "len" field is only three bits. Since the data must be
4 byte aligned, this field is shifted left by 2, giving a
max length of 28 bytes. If the data load is greater than 28
bytes, the first array field holds the full length of the
data load and the len field is set to zero.
Example, data size of 7 bytes:
type = RINGBUF_TYPE_DATA
len = 2
time_delta: <time-stamp> - <prev_event-time-stamp>
array[0..1]: <7 bytes of data> <1 byte empty>
This event is saved in 12 bytes of the buffer.
An event with 82 bytes of data:
type = RINGBUF_TYPE_DATA
len = 0
time_delta: <time-stamp> - <prev_event-time-stamp>
array[0]: 84 (Note the alignment)
array[1..14]: <82 bytes of data> <2 bytes empty>
The above event is saved in 92 bytes (if my math is correct).
82 bytes of data, 2 bytes empty, 4 byte header, 4 byte length.
Do not reference the above event struct directly. Use the following
functions to gain access to the event table, since the
ring_buffer_event structure may change in the future.
ring_buffer_event_length(event): get the length of the event.
This is the size of the memory used to record this
event, and not the size of the data pay load.
ring_buffer_time_delta(event): get the time delta of the event
This returns the delta time stamp since the last event.
Note: Even though this is in the header, there should
be no reason to access this directly, accept
for debugging.
ring_buffer_event_data(event): get the data from the event
This is the function to use to get the actual data
from the event. Note, it is only a pointer to the
data inside the buffer. This data must be copied to
another location otherwise you risk it being written
over in the buffer.
ring_buffer_lock: A way to lock the entire buffer.
ring_buffer_unlock: unlock the buffer.
ring_buffer_alloc: create a new ring buffer. Can choose between
overwrite or consumer/producer mode. Overwrite will
overwrite old data, where as consumer producer will
throw away new data if the consumer catches up with the
producer. The consumer/producer is the default.
ring_buffer_free: free the ring buffer.
ring_buffer_resize: resize the buffer. Changes the size of each cpu
buffer. Note, it is up to the caller to provide that
the buffer is not being used while this is happening.
This requirement may go away but do not count on it.
ring_buffer_lock_reserve: locks the ring buffer and allocates an
entry on the buffer to write to.
ring_buffer_unlock_commit: unlocks the ring buffer and commits it to
the buffer.
ring_buffer_write: writes some data into the ring buffer.
ring_buffer_peek: Look at a next item in the cpu buffer.
ring_buffer_consume: get the next item in the cpu buffer and
consume it. That is, this function increments the head
pointer.
ring_buffer_read_start: Start an iterator of a cpu buffer.
For now, this disables the cpu buffer, until you issue
a finish. This is just because we do not want the iterator
to be overwritten. This restriction may change in the future.
But note, this is used for static reading of a buffer which
is usually done "after" a trace. Live readings would want
to use the ring_buffer_consume above, which will not
disable the ring buffer.
ring_buffer_read_finish: Finishes the read iterator and reenables
the ring buffer.
ring_buffer_iter_peek: Look at the next item in the cpu iterator.
ring_buffer_read: Read the iterator and increment it.
ring_buffer_iter_reset: Reset the iterator to point to the beginning
of the cpu buffer.
ring_buffer_iter_empty: Returns true if the iterator is at the end
of the cpu buffer.
ring_buffer_size: returns the size in bytes of each cpu buffer.
Note, the real size is this times the number of CPUs.
ring_buffer_reset_cpu: Sets the cpu buffer to empty
ring_buffer_reset: sets all cpu buffers to empty
ring_buffer_swap_cpu: swaps a cpu buffer from one buffer with a
cpu buffer of another buffer. This is handy when you
want to take a snap shot of a running trace on just one
cpu. Having a backup buffer, to swap with facilitates this.
Ftrace max latencies use this.
ring_buffer_empty: Returns true if the ring buffer is empty.
ring_buffer_empty_cpu: Returns true if the cpu buffer is empty.
ring_buffer_record_disable: disable all cpu buffers (read only)
ring_buffer_record_disable_cpu: disable a single cpu buffer (read only)
ring_buffer_record_enable: enable all cpu buffers.
ring_buffer_record_enabl_cpu: enable a single cpu buffer.
ring_buffer_entries: The number of entries in a ring buffer.
ring_buffer_overruns: The number of entries removed due to writing wrap.
ring_buffer_time_stamp: Get the time stamp used by the ring buffer
ring_buffer_normalize_time_stamp: normalize the ring buffer time stamp
into nanosecs.
I still need to implement the GTOD feature. But we need support from
the cpu frequency infrastructure. But this can be done at a later
time without affecting the ring buffer interface.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the boot/initcall tracer.
It's primary purpose is to be able to trace the initcalls.
It is intended to be used with scripts/bootgraph.pl after some small
improvements.
Note that it is not active after its init. To avoid tracing (and so
crashing) before the whole tracing engine init, you have to explicitly
call start_boot_trace() after do_pre_smp_initcalls() to enable it.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Turn marker synchronize unregister into a static inline. There is no
reason to keep it as a macro over a static inline.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Create marker_synchronize_unregister() which must be called before the end of
exit() to make sure every probe callers have exited the non preemptible section
and thus are not executing the probe code anymore.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Offer mmiotrace users a function to inject markers from inside the kernel.
This depends on the trace_vprintk() patch.
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
ftrace_release is necessary for all uses of dynamic ftrace and not just
the archs that have CONFIG_FTRACE_MCOUNT_RECORD defined.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix:
kernel/built-in.o: In function `ftrace_dump':
(.text+0x2e2ea): undefined reference to `ftrace_kill_atomic'
Signed-off-by: Ingo Molnar <mingo@elte.hu>
At OLS I had a lot of interest to be able to have the ftrace buffers
dumped on panic. Usually one would expect to uses kexec and examine
the buffers after a new kernel is loaded. But sometimes the resources
do not permit kdump and kexec, so having an option to still see the
sequence of events up to the crash is very advantageous.
This patch adds the option to have the ftrace buffers dumped to the
console in the latency_trace format on a panic. When the option is set,
the default entries per CPU buffer are lowered to 16384, since the writing
to the serial (if that is the console) may take an awful long time
otherwise.
[
Changes since -v1:
Got alpine to send correctly (as well as spell check working).
Removed config option.
Moved the static variables into ftrace_dump itself.
Gave printk a log level.
]
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Based on Randy Dunlap's suggestion, the ftrace_printk kernel-doc belongs
with the ftrace_printk macro that should be used. Not with the
__ftrace_printk internal function.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds a feature that can help kernel developers debug their
code using ftrace.
int ftrace_printk(const char *fmt, ...);
This records into the ftrace buffer using printf formatting. The entry
size in the buffers are still a fixed length. A new type has been added
that allows for more entries to be used for a single recording.
The start of the print is still the same as the other entries.
It returns the number of characters written to the ftrace buffer.
For example:
Having a module with the following code:
static int __init ftrace_print_test(void)
{
ftrace_printk("jiffies are %ld\n", jiffies);
return 0;
}
Gives me:
insmod-5441 3...1 7569us : ftrace_print_test: jiffies are 4296626666
for the latency_trace file and:
insmod-5441 [03] 1959.370498: ftrace_print_test jiffies are 4296626666
for the trace file.
Note: Only the infrastructure should go into the kernel. It is to help
facilitate debugging for other kernel developers. Calls to ftrace_printk
is not intended to be left in the kernel, and should be frowned upon just
like scattering printks around in the code.
But having this easily at your fingertips helps the debugging go faster
and bugs be solved quicker.
Maybe later on, we can hook this with markers and have their printf format
be sucked into ftrace output.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When a mcount pointer is recorded into a table, it is used to add or
remove calls to mcount (replacing them with nops). If the code is removed
via removing a module, the pointers still exist. At modifying the code
a check is always made to make sure the code being replaced is the code
expected. In-other-words, the code being replaced is compared to what
it is expected to be before being replaced.
There is a very small chance that the code being replaced just happens
to look like code that calls mcount (very small since the call to mcount
is relative). To remove this chance, this patch adds ftrace_release to
allow module unloading to remove the pointers to mcount within the module.
Another change for init calls is made to not trace calls marked with
__init. The tracing can not be started until after init is done anyway.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The notrace define belongs in compiler.h so that it can be used in
init.h
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When enabling or disabling CONFIG_FTRACE_MCOUNT_RECORD, we want a full
kernel compile to handle the adding of the __mcount_loc sections.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch enables the loading of the __mcount_section of modules and
changing all the callers of mcount into nops.
The modification is done before the init_module function is called, so
again, we do not need to use kstop_machine to make these changes.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This is the infrastructure to the converting the mcount call sites
recorded by the __mcount_loc section into nops on boot. It also allows
for using these sites to enable tracing as normal. When the __mcount_loc
section is used, the "ftraced" kernel thread is disabled.
This uses the current infrastructure to record the mcount call sites
as well as convert them to nops. The mcount function is kept as a stub
on boot up and not converted to the ftrace_record_ip function. We use the
ftrace_record_ip to only record from the table.
This patch does not handle modules. That comes with a later patch.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kprobes already has an extensive list of annotations for functions
that should not be instrumented. Add notrace annotations to these
functions as well.
This is particularly useful for functions called by the NMI path.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Implementation of kernel tracepoints. Inspired from the Linux Kernel
Markers. Allows complete typing verification by declaring both tracing
statement inline functions and probe registration/unregistration static
inline functions within the same macro "DEFINE_TRACE". No format string
is required. See the tracepoint Documentation and Samples patches for
usage examples.
Taken from the documentation patch :
"A tracepoint placed in code provides a hook to call a function (probe)
that you can provide at runtime. A tracepoint can be "on" (a probe is
connected to it) or "off" (no probe is attached). When a tracepoint is
"off" it has no effect, except for adding a tiny time penalty (checking
a condition for a branch) and space penalty (adding a few bytes for the
function call at the end of the instrumented function and adds a data
structure in a separate section). When a tracepoint is "on", the
function you provide is called each time the tracepoint is executed, in
the execution context of the caller. When the function provided ends its
execution, it returns to the caller (continuing from the tracepoint
site).
You can put tracepoints at important locations in the code. They are
lightweight hooks that can pass an arbitrary number of parameters, which
prototypes are described in a tracepoint declaration placed in a header
file."
Addition and removal of tracepoints is synchronized by RCU using the
scheduler (and preempt_disable) as guarantees to find a quiescent state
(this is really RCU "classic"). The update side uses rcu_barrier_sched()
with call_rcu_sched() and the read/execute side uses
"preempt_disable()/preempt_enable()".
We make sure the previous array containing probes, which has been
scheduled for deletion by the rcu callback, is indeed freed before we
proceed to the next update. It therefore limits the rate of modification
of a single tracepoint to one update per RCU period. The objective here
is to permit fast batch add/removal of probes on _different_
tracepoints.
Changelog :
- Use #name ":" #proto as string to identify the tracepoint in the
tracepoint table. This will make sure not type mismatch happens due to
connexion of a probe with the wrong type to a tracepoint declared with
the same name in a different header.
- Add tracepoint_entry_free_old.
- Change __TO_TRACE to get rid of the 'i' iterator.
Masami Hiramatsu <mhiramat@redhat.com> :
Tested on x86-64.
Performance impact of a tracepoint : same as markers, except that it
adds about 70 bytes of instructions in an unlikely branch of each
instrumented function (the for loop, the stack setup and the function
call). It currently adds a memory read, a test and a conditional branch
at the instrumentation site (in the hot path). Immediate values will
eventually change this into a load immediate, test and branch, which
removes the memory read which will make the i-cache impact smaller
(changing the memory read for a load immediate removes 3-4 bytes per
site on x86_32 (depending on mov prefixes), or 7-8 bytes on x86_64, it
also saves the d-cache hit).
About the performance impact of tracepoints (which is comparable to
markers), even without immediate values optimizations, tests done by
Hideo Aoki on ia64 show no regression. His test case was using hackbench
on a kernel where scheduler instrumentation (about 5 events in code
scheduler code) was added.
Quoting Hideo Aoki about Markers :
I evaluated overhead of kernel marker using linux-2.6-sched-fixes git
tree, which includes several markers for LTTng, using an ia64 server.
While the immediate trace mark feature isn't implemented on ia64, there
is no major performance regression. So, I think that we don't have any
issues to propose merging marker point patches into Linus's tree from
the viewpoint of performance impact.
I prepared two kernels to evaluate. The first one was compiled without
CONFIG_MARKERS. The second one was enabled CONFIG_MARKERS.
I downloaded the original hackbench from the following URL:
http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c
I ran hackbench 5 times in each condition and calculated the average and
difference between the kernels.
The parameter of hackbench: every 50 from 50 to 800
The number of CPUs of the server: 2, 4, and 8
Below is the results. As you can see, major performance regression
wasn't found in any case. Even if number of processes increases,
differences between marker-enabled kernel and marker- disabled kernel
doesn't increase. Moreover, if number of CPUs increases, the differences
doesn't increase either.
Curiously, marker-enabled kernel is better than marker-disabled kernel
in more than half cases, although I guess it comes from the difference
of memory access pattern.
* 2 CPUs
Number of | without | with | diff | diff |
processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] |
--------------------------------------------------------------
50 | 4.811 | 4.872 | +0.061 | +1.27 |
100 | 9.854 | 10.309 | +0.454 | +4.61 |
150 | 15.602 | 15.040 | -0.562 | -3.6 |
200 | 20.489 | 20.380 | -0.109 | -0.53 |
250 | 25.798 | 25.652 | -0.146 | -0.56 |
300 | 31.260 | 30.797 | -0.463 | -1.48 |
350 | 36.121 | 35.770 | -0.351 | -0.97 |
400 | 42.288 | 42.102 | -0.186 | -0.44 |
450 | 47.778 | 47.253 | -0.526 | -1.1 |
500 | 51.953 | 52.278 | +0.325 | +0.63 |
550 | 58.401 | 57.700 | -0.701 | -1.2 |
600 | 63.334 | 63.222 | -0.112 | -0.18 |
650 | 68.816 | 68.511 | -0.306 | -0.44 |
700 | 74.667 | 74.088 | -0.579 | -0.78 |
750 | 78.612 | 79.582 | +0.970 | +1.23 |
800 | 85.431 | 85.263 | -0.168 | -0.2 |
--------------------------------------------------------------
* 4 CPUs
Number of | without | with | diff | diff |
processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] |
--------------------------------------------------------------
50 | 2.586 | 2.584 | -0.003 | -0.1 |
100 | 5.254 | 5.283 | +0.030 | +0.56 |
150 | 8.012 | 8.074 | +0.061 | +0.76 |
200 | 11.172 | 11.000 | -0.172 | -1.54 |
250 | 13.917 | 14.036 | +0.119 | +0.86 |
300 | 16.905 | 16.543 | -0.362 | -2.14 |
350 | 19.901 | 20.036 | +0.135 | +0.68 |
400 | 22.908 | 23.094 | +0.186 | +0.81 |
450 | 26.273 | 26.101 | -0.172 | -0.66 |
500 | 29.554 | 29.092 | -0.461 | -1.56 |
550 | 32.377 | 32.274 | -0.103 | -0.32 |
600 | 35.855 | 35.322 | -0.533 | -1.49 |
650 | 39.192 | 38.388 | -0.804 | -2.05 |
700 | 41.744 | 41.719 | -0.025 | -0.06 |
750 | 45.016 | 44.496 | -0.520 | -1.16 |
800 | 48.212 | 47.603 | -0.609 | -1.26 |
--------------------------------------------------------------
* 8 CPUs
Number of | without | with | diff | diff |
processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] |
--------------------------------------------------------------
50 | 2.094 | 2.072 | -0.022 | -1.07 |
100 | 4.162 | 4.273 | +0.111 | +2.66 |
150 | 6.485 | 6.540 | +0.055 | +0.84 |
200 | 8.556 | 8.478 | -0.078 | -0.91 |
250 | 10.458 | 10.258 | -0.200 | -1.91 |
300 | 12.425 | 12.750 | +0.325 | +2.62 |
350 | 14.807 | 14.839 | +0.032 | +0.22 |
400 | 16.801 | 16.959 | +0.158 | +0.94 |
450 | 19.478 | 19.009 | -0.470 | -2.41 |
500 | 21.296 | 21.504 | +0.208 | +0.98 |
550 | 23.842 | 23.979 | +0.137 | +0.57 |
600 | 26.309 | 26.111 | -0.198 | -0.75 |
650 | 28.705 | 28.446 | -0.259 | -0.9 |
700 | 31.233 | 31.394 | +0.161 | +0.52 |
750 | 34.064 | 33.720 | -0.344 | -1.01 |
800 | 36.320 | 36.114 | -0.206 | -0.57 |
--------------------------------------------------------------
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: 'Peter Zijlstra' <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merges oprofile, timers/hpet, x86/traps, x86/time, and x86/core misc items.
* 'x86-core-v4-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (132 commits)
x86: change early_ioremap to use slots instead of nesting
x86: adjust dependencies for CONFIG_X86_CMOV
dumpstack: x86: various small unification steps, fix
x86: remove additional_cpus
x86: remove additional_cpus configurability
x86: improve UP kernel when CPU-hotplug and SMP is enabled
dumpstack: x86: various small unification steps
dumpstack: i386: make kstack= an early boot-param and add oops=panic
dumpstack: x86: use log_lvl and unify trace formatting
dumptrace: x86: consistently include loglevel, print stack switch
dumpstack: x86: add "end" parameter to valid_stack_ptr and print_context_stack
dumpstack: x86: make printk_address equal
dumpstack: x86: move die_nmi to dumpstack_32.c
traps: x86: finalize unification of traps.c
traps: x86: make traps_32.c and traps_64.c equal
traps: x86: various noop-changes preparing for unification of traps_xx.c
traps: x86_64: use task_pid_nr(tsk) instead of tsk->pid in do_general_protection
traps: i386: expand clear_mem_error and remove from mach_traps.h
traps: x86_64: make io_check_error equal to the one on i386
traps: i386: use preempt_conditional_sti/cli in do_int3
...
Move the set up on ldisc change into the ldisc
Move the INQ/OUTQ cases into the driver not in shared ioctl code where it
gives bogus answers for other ldisc values
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pass-in 'inode' or 'tty' parameter to devpts interfaces. With multiple
devpts instances, these parameters will be used in subsequent patches
to identify the instance of devpts mounted. The parameters also help
simplify devpts implementation.
Changelog[v3]:
- minor changes due to merge with ttydev updates
- rename parameters to emphasize they are ptmx or pts inodes
- pass-in tty_struct * to devpts_pty_kill() (this will help
cleanup the get_node() call in a subsequent patch)
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The majority of the remaining init_dev code is pty special cases. We
refactor this code into the driver->install method.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Original suggestion and proposal from Sukadev Bhattiprolu.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have the lookup operation abstracted which is nice for pty cleanup but
we really want to abstract the add/remove entries as well so that we can
pull the pty code out of the tty core and create a clear defined interface
for the tty driver table.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix up the naming, style and extract some bits of code into the driver
specific code
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Carry on pushing code out of tty_io when it belongs to other drivers. I'm
not 100% happy with some of this and it will be worth revisiting some of the
exports later when the restructuring work is done.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now there are various drivers that try to use tty->count to know when
they get the final close. Aristeau Rozanski showed while debugging the vt
sysfs race that this isn't entirely safe.
Instead of driver side tricks to work around this introduce a shutdown which
is called when the tty is being destructed. This also means that the shutdown
method is tied into the refcounting.
Use this to rework the console close/sysfs logic.
Remove lots of special case code from the tty core code. The pty code can now
have a shutdown() method that replaces the special case hackery in the tree
free up paths.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We now have the infrastructure to sort this out but rather than teaching
the syscall tty lock rules we move the hard work into a tty helper
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use kref in the USB serial drivers so that we don't free tty structures
from under the URB receive handlers as has historically been the case if
you were unlucky. This also gives us a framework for general tty drivers to
use tty_port objects and refcount.
Contains two err->dev_err changes merged together to fix clashes in the
-next tree.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need a way to describe the various additional modes and flow control
features that random weird hardware shows up and software such as wine
wants to emulate as Windows supports them.
TCGETX/TCSETX and the termiox ioctl are a SYS5 extension that we might as
well adopt. This patches adds the structures and the basic ioctl interfaces
when the TCGETX etc defines are added for an architecture. Drivers wishing
to use this stuff need to add new methods.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
JP Tosoni observed:
"About a RS485 ioctl: could you consider the attached files which are
already in the Linux kernel (in include/asm-cris). They define a
TIOCSERSETRS485 (ioctl.h), and the data structure (rs485.h)
with allows to specify timings. Sounds just like what we want ?"
and he's right: sort of. Rework the structure to use flag bits and make the
time delay a fixed sized field so we don't get 32/64bit problems. Add the ioctls
to x86 so that people know what to add to their platform of choice.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a kref to the tty structure and use it to protect the tty->signal
tty references. For now we don't introduce it for anything else.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a new line discipline for "pulse per second" devices connected to
a serial port.
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The two are basically independent chunks of code so lets split them up for
readability and sanity. It also makes the API boundaries much clearer.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Otherwise the top 32-bits of the resource value get chopped
off on 64-bit systems, and the resulting I/O accesses go to
random places.
Thanks to testing and debugging by Josip Rodin, which helped
track this down.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix kconfig typo and extra whitespace
ext4: fix build failure without procfs
ext4: add an option to control error handling on file data
jbd2: don't dirty original metadata buffer on abort
ext4: add checks for errors from jbd2
jbd2: fix error handling for checkpoint io
jbd2: abort when failed to log metadata buffers
This merges in:
x86/build, x86/microcode, x86/spinlocks, x86/memory-corruption-check,
x86/early-printk, x86/xsave, x86/quirks, x86/setup, x86/signal,
core/signal, x86/urgent, x86/xen
* 'x86-core-v2-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (142 commits)
x86: make processor type select depend on CONFIG_EMBEDDED
x86: extend processor type select help text
x86, amd-iommu: propagate PCI device enabling error
warnings: fix arch/x86/kernel/io_apic_64.c
warnings: fix arch/x86/kernel/early_printk.c
x86, fpu: check __clear_user() return value
x86: memory corruption check - cleanup
x86: ioperm user_regset
xen: do not reserve 2 pages of padding between hypervisor and fixmap.
xen: use spin_lock_nest_lock when pinning a pagetable
x86: xsave: set FP, SSE bits in the xsave header in the user sigcontext
x86: xsave: fix error condition in save_i387_xstate()
x86: SB450: deprioritize DMI quirks
x86: SB450: skip IRQ0 override if it is not routed to INT2 of IOAPIC
x86: replace a magic number with a named constant in the VESA boot code
x86 setup: remove IMAGE_OFFSET
x86 setup: remove DEF_INITSEG and DEF_SETUPSEG
Revert "x86: fix ghost EDD devices in /sys again"
x86 setup: fix ghost entries under /sys/firmware/edd take 3
x86: signal: remove indent in restore_sigcontext()
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc: (24 commits)
MMC: Use timeout values from CSR
MMC: CSD and CID timeout values
sdhci: 'scratch' may be used uninitialized
mmc: explicitly mention SDIO support in Kconfig
mmc: remove redundant "depends on"
Fix comment in include/linux/mmc/host.h
sdio: high-speed support
mmc_block: hard code 512 byte block size
sdhci: force high speed capability on some controllers
mmc_block: filter out PC requests
mmc_block: indicate strict ordering
mmc_block: inform block layer about sector count restriction
sdio: give sdio irq thread a host specific name
sdio: make sleep on error interruptable
sdhci: reduce card detection delay
sdhci: let the controller wait for busy state to end
atmel-mci: Add missing flush_dcache_page() in PIO transfer code
atmel-mci: Don't overwrite error bits when NOTBUSY is set
atmel-mci: Add experimental DMA support
atmel-mci: support multiple mmc slots
...
Tim Bird