Commit graph

116763 commits

Author SHA1 Message Date
David Brownell
a10f9e7caf i2c: Do earlier driver model init
Move I2C driver model init earlier in the boot sequence.

This avoids oopsing in statically linked systems when some
subsystems register I2C drivers in subsys_initcall() code,
but those subsystems are linked (and initialized) before I2C.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:06 +02:00
Jean Delvare
f1453ee3a4 i2c: Only build Tyan SMBus mux drivers on x86
The two Tyan SMBus mux drivers (i2c-amd756-s4882 and i2c-nforce2-s4985)
are only useful on specific x86 motherboards, so there is no point in
letting them be built on other architectures.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:06 +02:00
David Brownell
1d0b19c9a0 i2c: Guard against oopses from bad init sequences
Guard I2C against oopsing because of init sequence problems, by
verifying that i2c_init() has been called before calling any
routines that rely on that initialization.  This specific test
just requires that bus_register(&i2c_bus_type) was called.

Examples of this kind of oopsing come from subystems and drivers
which register I2C drivers in their subsys_initcall code but
which are statically linked before I2C by drivers/Makefile.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:05 +02:00
Jean Delvare
7c15fd1249 i2c: Document the implementation details of the /dev interface
I wrote this explanation to answer a question on the i2c mailing list,
and thought it would be good to have in the kernel documentation.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:05 +02:00
Jean Delvare
fceb2d0680 i2c: Improve dev-interface documentation
* Clarify some points.
* Point developers to i2c-tools instead of lm_sensors.
* Fix coding style in code examples.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:05 +02:00
Jean Delvare
9def255631 i2c-parport-light: Don't register a platform device resource
The i2c-parport-light driver isn't a real platform driver, so it
should not instantiate platform devices with resources. The resource
management system can't cope with colliding resources, and we are
likely to create such a colliding resource.

So, better just try to grab the I/O ports we need right at module
initialization time, and bail out if we can't. It has the added
benefit that the module will no longer load if it isn't going to work,
which is definitely more user-friendly.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:04 +02:00
Jean Delvare
67a37308ae hwmon: (dme1737) Convert to a new-style i2c driver
The new-style dme1737 driver implements the optional detect() callback
to cover the use cases of the legacy driver. I don't actually expect
any new-style device for that driver, but as the old i2c API is going
away soon, we have to switch to the new one.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Juerg Haefliger <juergh@gmail.com>
2008-10-14 17:30:04 +02:00
Jean Delvare
dbc2bc251e hwmon: (dme1737) Be less i2c-centric
The dme1737 driver support both LPC (ISA) and SMBus devices. At the
moment it's rather i2c-centric, and LPC variants use a fake i2c_client
for some operations.

In a near future, i2c_client will be allocated by i2c-core rather than
by the device drivers, so non-i2c drivers will not have one. As a
preparation step, change the driver code to no longer assume that
an i2c_client structure is always available. No functional change.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Juerg Haefliger <juergh@gmail.com>
2008-10-14 17:30:04 +02:00
Marek Vasut
b84ee0b0c7 i2c/tps65010: Vibrator hookup to gpiolib
All the tps6501{0,1,2,3,4} chips have a signal for hooking up with
a vibrator (for non-auditory cell phone "ring") ... expose that as
one more (output-only) GPIO.

[ dbrownell@users.sourceforge.net: comments; list tps65014 too ]

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:04 +02:00
Rudolf Marek
b806a71a0e i2c-viapro: Add VX800/VX820 support
Thanks to new datasheets published on http://linux.via.com.tw we can now add 
support for VX800/VX820 chipsets.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:03 +02:00
Paul Mundt
4ad48e6ab1 i2c: Renesas Highlander FPGA SMBus support
This adds support for the SMBus adapter found in the various FPGAs on
the Renesas Highlander platforms. Particularly the R0P7780LC0011RL and
R0P7785LC0011RL FPGAs.

Functionality is fairly restricted, in that only byte and block data
transfers are supported. Normal/fast mode and IRQ/polling are also
supported. Primarily used for various RTCs and thermal sensors.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:03 +02:00
Rene Herman
ce5640330b i2c-pca-isa: Don't grab arbitrary resources
Grabbing ISA bus resources without anything or anyone telling us we
should can break boot on randconfig/allyesconfig builds by keeping
resources that are in fact owned by different hardware busy and does
as reported by Ingo Molnar.

Generally it's also dangerous to just poke at random I/O ports and
especially those in the range where other old easily confused ISA
hardware might live.

For this specialized I2C bus driver, insist that the user specifies
the resources before grabbing them.

The^WA user of this driver is a one time

echo "options i2c-pca-isa base=0x330 irq=10" >> /etc/modprobe.conf

away from the old behaviour.

Signed-off-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-14 17:30:03 +02:00
Jean Delvare
9df013b3e4 i2c/isp1301_omap: Convert to a new-style i2c driver, part 2
Based on David Brownell's patch for tps65010 and previous work by
Felipe Balbi, this patch finishes converting isp1301_omap to a
new-style i2c driver.

There's definitely room for further drivers cleanups, but these are
out of the scope of this patch.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Tony Lindgren <tony@atomide.com>
2008-10-14 17:30:02 +02:00
Felipe Balbi
a5f08a327a i2c/isp1301_omap: Convert to a new-style i2c driver, part 1
Based on David Brownell's patch for tps65010, this patch
starts converting isp1301_omap.c to new-style i2c driver.

Signed-off-by: Felipe Balbi <me@felipebalbi.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Tony Lindgren <tony@atomide.com>
2008-10-14 17:30:02 +02:00
Oleg Nesterov
8546232355 do_generic_file_read: s/EINTR/EIO/ if lock_page_killable() fails
If lock_page_killable() fails because the task was killed by SIGKILL or
any other fatal signal, do_generic_file_read() returns -EIO.

This seems to be OK, because in fact the userspace won't see this error,
the task will dequeue SIGKILL and exit.

However, /sbin/init is different, it will dequeue SIGKILL, ignore it, and
return to the user-space with the bogus -EIO.

Change the code to return the error code from lock_page_killable(), -EINTR.
This doesn't fix the bug, but perhaps makes sense anyway. Imho, with this
change the code looks a bit more logical, and the "good" init should handle
the spurious EINTR or short read.

Afaics we can also change lock_page_killable() to return -ERESTARTNOINTR,
but this can't prevent the short reads.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 17:15:33 +02:00
Aneesh Kumar K.V
74baaaaec8 vfs: Remove the range_cont writeback mode.
Ext4 was the only user of range_cont writeback mode and ext4 switched
to a different method. So remove the range_cont mode which is not used
in the kernel.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
CC: linux-fsdevel@vger.kernel.org
2008-10-14 09:21:02 -04:00
Aneesh Kumar K.V
af6f029d38 ext4: Use tag dirty lookup during mpage_da_submit_io
This enables us to drop the range_cont writeback mode
use from ext4_da_writepages.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2008-10-14 09:20:19 -04:00
Theodore Ts'o
8a0aba733d ext4: let the block device know when unused blocks can be discarded
Let the block device know when unused blocks can be discarded, using
the new sb_issue_discard() interface.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-16 10:06:27 -04:00
Yoshihiro Shimoda
6028aa01f7 [MTD] [NAND] sh_flctl: add support for Renesas SuperH FLCTL
Several Renesas SuperH CPU has FLCTL. The FLCTL support NAND Flash.
This driver support SH7723.

Signed-off-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-10-14 13:33:05 +01:00
Ingo Molnar
98d9c66ab0 tracing/fastboot: improve help text
Improve the help text of the boot tracer.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 14:27:20 +02:00
Ingo Molnar
4519d9e54d tracing/stacktrace: improve help text
Improve the help text that is displayed for CONFIG_STACK_TRACER.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 14:15:43 +02:00
Richard Genoud
3fc2389847 [MTD] [NAND] Bug on atmel_nand HW ECC : OOB info not correctly written
The functions that write the OOB info (on hardware ECC only) use the 
HW_SYNDROME method.

This is not correct : the start position is "pos = eccsize + chunk" and 
should be eccsize. So, the standard (nand_write_oob_std) function should 
be used. This patch corrects this by using NAND_ECC_HW instead of 
NAND_ECC_HW_SYNDROME.

This has only been tested on small pages nand flash.
(if anyone can test it on large pages that would be great).

kernel version : 2.6.27-rc2 (current git mtd-2.6)

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-10-14 11:07:57 +01:00
David Woodhouse
08d7904329 [MTD] [MAPS] Remove unused variable after ROM API cleanup.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-10-14 11:00:51 +01:00
Chen Gong
daa847356a [MTD] m25p80.c extended jedec support (v2)
Include missing parts of previous patch.

Signed-off-by: Chen Gong <g.chen@freescale.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-10-14 10:59:43 +01:00
Marc Zyngier
8825e8e8d0 ALSA: Fix pxa2xx-ac97-lib.c compilation
The last ALSA merge broke pxa2xx-ac97-lib.c, as it brought back
references to cpu_is_pxa21x that Eric Miao removed in commit
0ffcbfd54e:

	[ARM] pxa: make cpu_is_pxa2* macros more consistent

This patch gets rid of those references, and only keeps cpu_is_pxa25x().

Signed-off-by: Marc Zyngier <maz@misterjones.org>
Acked-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2008-10-14 11:02:21 +02:00
Frederic Weisbecker
07d1890420 tracing/fastboot: fix initcalls disposition in bootgraph.pl
When bootgraph.pl parses a file, it gives one row
for each initcall's pid. But only few of them will
be displayed => the longest.

This patch corrects it by giving only a rows for pids
which have initcalls that will be displayed.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:34 +02:00
Arnaud Patard
5c542368a3 tracing/fastboot: fix bootgraph.pl initcall name regexp
The regexp used to match the start and the end of an initcall
are matching only on [a-zA-Z\_]. This rules out initcalls with
a number in them. This patch is fixing that.

Signed-off-by: Arnaud Patard <apatard@mandriva.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:33 +02:00
Arjan van de Ven
80a398a55d tracing/fastboot: fix issues and improve output of bootgraph.pl
David Sanders reported some issues with bootgraph.pl's display
of his sytems bootup; this commit fixes these by scaling the graph
not from 0 - end time but from the first initcall to the end time;
the minimum display size etc also now need to scale with this, as does
the axis display.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-10-14 10:39:32 +02:00
Mathieu Desnoyers
231375cc5c tracepoints: synchronize unregister static inline
Turn tracepoint 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>
2008-10-14 10:39:31 +02:00
Mathieu Desnoyers
f2461fc82a tracepoints: tracepoint_synchronize_unregister()
Create tracepoint_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>
2008-10-14 10:39:30 +02:00
Anders Kaseorg
8b27386a9c ftrace: make ftrace_test_p6nop disassembler-friendly
Commit 4c3dc21b136f8cb4b72afee16c3ba7e961656c0b in tip introduced the
5-byte NOP ftrace_test_p6nop:

   jmp . + 5
   .byte 0x00, 0x00, 0x00

This is not friendly to disassemblers because an odd number of 0x00s
ends in the middle of an instruction boundary.  This changes the 0x00s
to 1-byte NOPs (0x90).

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:29 +02:00
Mathieu Desnoyers
bfadadfccc markers: fix synchronize marker unregister static inline
Use a #define for synchronize marker unregister to fix include dependencies.

Fixes the slab circular inclusion which triggers when slab.git is combined
with tracing.git, where rcupdate includes slab, which includes markers
which includes rcupdate.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:28 +02:00
Tim Bird
ca538f6bbe tracing/fastboot: add better resolution to initcall debug/tracing
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>
2008-10-14 10:39:27 +02:00
Harvey Harrison
ad0a3b6811 trace: add build-time check to avoid overrunning hex buffer
Remove the runtime BUG_ON and change to a compile-time check in
the macro that calls the hex format routine

[Noticed by Joe Perches]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:26 +02:00
Harvey Harrison
2fbc474901 ftrace: fix hex output mode of ftrace
Fix the output of ftrace in hex mode as the hi/lo nibbles are output in
reverse order. Without this patch, the output of ftrace is:

raw mode : 6474 0 141531612444 0 140 + 6402 120 S
hex mode : 000091a4 00000000 000000023f1f50c1 00000000 c8 000000b2 00009120 87 ffff00c8 00000035

There is an inversion on ouput hex(6474) is 194a

[based on a patch by Philippe Reynes <tremyfr@yahoo.fr>]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:25 +02:00
Frederic Weisbecker
ddc7a01aad tracing/fastboot: fix initcalls disposition in bootgraph.pl
When bootgraph.pl parses a file, it gives one row
for each initcall's pid. But only few of them will
be displayed => the longest.

This patch corrects it by giving only a rows for pids
which have initcalls that will be displayed.

[ mingo@elte.hu: resolved conflicts ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:24 +02:00
Arjan van de Ven
8a5d900cca tracing/fastboot: fix printk format typo in boot tracer
When printing nanoseconds, the right printk format string is %09 not %06...

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Frédéric Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:23 +02:00
Frederic Weisbecker
c2931e05ec ftrace: return an error when setting a nonexistent tracer
When one try to set a nonexistent tracer, no error is returned
as if the name of the tracer was correct.
We should return -EINVAL.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:22 +02:00
Steven Rostedt
3ea2e6d71a ftrace: make some tracers reentrant
Now that the ring buffer is reentrant, some of the ftrace tracers
(sched_swich, debugging traces) can also be reentrant.

Note: Never make the function tracer reentrant, that can cause
  recursion problems all over the kernel. The function tracer
  must disable reentrancy.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:20 +02:00
Steven Rostedt
bf41a158ca ring-buffer: make reentrant
This patch replaces the local_irq_save/restore with preempt_disable/
enable. This allows for interrupts to enter while recording.
To write to the ring buffer, you must reserve data, and then
commit it. During this time, an interrupt may call a trace function
that will also record into the buffer before the commit is made.

The interrupt will reserve its entry after the first entry, even
though the first entry did not finish yet.

The time stamp delta of the interrupt entry will be zero, since
in the view of the trace, the interrupt happened during the
first field anyway.

Locking still takes place when the tail/write moves from one page
to the next. The reader always takes the locks.

A new page pointer is added, called the commit. The write/tail will
always point to the end of all entries. The commit field will
point to the last committed entry. Only this commit entry may
update the write time stamp.

The reader can only go up to the commit. It cannot go past it.

If a lot of interrupts come in during a commit that fills up the
buffer, and it happens to make it all the way around the buffer
back to the commit, then a warning is printed and new events will
be dropped.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:19 +02:00
Steven Rostedt
6f807acd27 ring-buffer: move page indexes into page headers
Remove the global head and tail indexes and move them into the
page header. Each page will now keep track of where the last
write and read was made. We also rename the head and tail to read
and write for better clarification.

This patch is needed for future enhancements to move the ring buffer
to a lockless solution.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:18 +02:00
Frederic Weisbecker
097d036a2f tracing/fastboot: only trace non-module initcalls
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>
2008-10-14 10:39:17 +02:00
Steven Rostedt
6450c1d321 ftrace: move pc counter in irqtrace
The assigning of the pc counter is in the wrong spot in the
check_critical_timing function. The pc variable is used in the
out jump.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:16 +02:00
Steven Rostedt
aa1e0e3bcf ring_buffer: map to cpu not page
My original patch had a compile bug when NUMA was configured. I
referenced cpu when it should have been cpu_buffer->cpu.

Ingo quickly fixed this bug by replacing cpu with 'i' because that
was the loop counter. Unfortunately, the 'i' was the counter of
pages, not CPUs. This caused a crash when the number of pages allocated
for the buffers exceeded the number of pages, which would usually
be the case.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:15 +02:00
Steven Noonan
eb7fa93527 ftrace: ktime.h not included in ftrace.h
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>
2008-10-14 10:39:14 +02:00
Ingo Molnar
3e1932ad59 tracing/fastboot: build fix
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>
2008-10-14 10:39:13 +02:00
Frederic Weisbecker
5601020feb tracing/fastboot: get the initcall name before it disappears
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>
2008-10-14 10:39:12 +02:00
Frederic Weisbecker
cb5ab74204 tracing/fastboot: change the printing of boot tracer according to bootgraph.pl
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>
2008-10-14 10:39:11 +02:00
Ingo Molnar
77ae11f63b ring-buffer: fix build error
fix:

 kernel/trace/ring_buffer.c: In function ‘rb_allocate_pages’:
 kernel/trace/ring_buffer.c:235: error: ‘cpu’ undeclared (first use in this function)
 kernel/trace/ring_buffer.c:235: error: (Each undeclared identifier is reported only once
 kernel/trace/ring_buffer.c:235: error: for each function it appears in.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:10 +02:00
Steven Rostedt
38697053fa ftrace: preempt disable over interrupt disable
With the new ring buffer infrastructure in ftrace, I'm trying to make
ftrace a little more light weight.

This patch converts a lot of the local_irq_save/restore into
preempt_disable/enable.  The original preempt count in a lot of cases
has to be sent in as a parameter so that it can be recorded correctly.
Some places were recording it incorrectly before anyway.

This is also laying the ground work to make ftrace a little bit
more reentrant, and remove all locking. The function tracers must
still protect from reentrancy.

Note: All the function tracers must be careful when using preempt_disable.
  It must do the following:

  resched = need_resched();
  preempt_disable_notrace();
  [...]
  if (resched)
	preempt_enable_no_resched_notrace();
  else
	preempt_enable_notrace();

The reason is that if this function traces schedule() itself, the
preempt_enable_notrace() will cause a schedule, which will lead
us into a recursive failure.

If we needed to reschedule before calling preempt_disable, we
should have already scheduled. Since we did not, this is most
likely that we should not and are probably inside a schedule
function.

If resched was not set, we still need to catch the need resched
flag being set when preemption was off and the if case at the
end will catch that for us.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:39:09 +02:00