If the first cmpxchg call succeeds, it is not necessary to use cpu_relax
before cmpxchg. So cpu_relax in a busy loop involving cmpxchg should go
after cmpxchg instead of before that. This patch fixes this in llist.
Signed-off-by: Huang Ying <ying.huang@intel.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <>
Glauber Costa [Wed, 28 Sep 2011 00:50:46 +0000 (10:50 +1000)]
lib/percpu_counter.c: enclose hotplug only variables in hotplug ifdef
These variables are only used when CONFIG_HOTPLUG_CPU is enabled, they are
ifdef'ed everywhere else. So don't define them when CONFIG_HOTPLUG_CPU is
not enabled.
Signed-off-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Andrew Morton <>
Cc: Andi Kleen <ak@linux.intel.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: H Hartley Sweeten <hartleys@visionengravers.com> Cc: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Len Brown <len.brown@intel.com> Signed-off-by: Andrew Morton <>
lib/bitmap.c: quiet sparse noise about address space
__bitmap_parse() and __bitmap_parselist() both take a pointer to a kernel
buffer as a parameter and then cast it to a pointer to user buffer for use
in cases when the parameter is_user indicates that the buffer is actually
located in user space. This casting, and the casts in the callers,
results in sparse noise like the following:
warning: incorrect type in initializer (different address spaces)
expected char const [noderef] <asn:1>*ubuf
got char const *buf
warning: cast removes address space of expression
Since these casts are intentional, use __force to quiet the noise.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Len Brown <len.brown@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <>
Akinobu Mita [Wed, 28 Sep 2011 00:50:45 +0000 (10:50 +1000)]
lib/spinlock_debug.c: print owner on spinlock lockup
When SPIN_BUG_ON is triggered, the lock owner information is reported.
But it is omitted when spinlock lockup is detected.
This information is useful especially on the architectures which don't
implement trigger_all_cpu_backtrace() that is called just after detecting
lockup. So report it and also avoid message format duplication.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <>
lib/kstrtox: common code between kstrto*() and simple_strto*() functions
Currently termination logic (\0 or \n\0) is hardcoded in _kstrtoull(),
avoid that for code reuse between kstrto*() and simple_strtoull().
Essentially, make them different only in termination logic.
simple_strtoull() (and scanf(), BTW) ignores integer overflow, that's a
bug we currently don't have guts to fix, making KSTRTOX_OVERFLOW hack
necessary.
Almost forgot: patch shrinks code size by about ~80 bytes on x86_64.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <>
My GPIOs are on an I2C port expander, so we must use the *_cansleep()
variant of the GPIO functions. This is was not being done in
create_gpio_led().
We can change gpio_get_value() to gpio_get_value_cansleep() because it is
only called from the platform_driver probe function, which is a context
where we can sleep.
Only tested on my gpio_cansleep() system, but it seems safe for all
systems.
Signed-off-by: David Daney <david.daney@cavium.com> Cc: Richard Purdie <rpurdie@rpsys.net> Acked-by: Trent Piepho <tpiepho@gmail.com> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Andrew Morton <>
Magnus Damm [Wed, 28 Sep 2011 00:50:44 +0000 (10:50 +1000)]
drivers/leds/leds-renesas-tpu.c: move Renesas TPU LED driver platform data
Use the platform_data include directory for the TPU LED driver, as
suggested by Paul Mundt.
Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Andrew Morton <>
Magnus Damm [Wed, 28 Sep 2011 00:50:44 +0000 (10:50 +1000)]
drivers/leds/leds-renesas-tpu.c: update driver to use workqueue
Use a workqueue in the Renesas TPU LED driver to allow the Runtime PM code
to sleep.
Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Andrew Morton <>
Wolfram Sang [Wed, 28 Sep 2011 00:50:43 +0000 (10:50 +1000)]
drivers/leds/leds-lm3530.c: remove obsolete cleanup for clientdata
A few new i2c-drivers came into the kernel which clear the
clientdata-pointer on exit or error. This is obsolete meanwhile, the core
will do it.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Cc: Richard Purdie <rpurdie@rpsys.net> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <>
Axel Lin [Wed, 28 Sep 2011 00:50:43 +0000 (10:50 +1000)]
leds-renesas-tpu-led-driver-v2-fix
include linux/module.h
Signed-off-by: Axel Lin <axel.lin@gmail.com> Cc: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Andrew Morton <>
Magnus Damm [Wed, 28 Sep 2011 00:50:42 +0000 (10:50 +1000)]
leds: Renesas TPU LED driver
Add V2 of the LED driver for a single timer channel for the TPU hardware
block commonly found in Renesas SoCs.
The driver has been written with optimal Power Management in mind, so to
save power the LED is driven as a regular GPIO pin in case of maximum
brightness and power off which allows the TPU hardware to be idle and
which in turn allows the clocks to be stopped and the power domain to be
turned off transparently.
Any other brightness level requires use of the TPU hardware in PWM mode.
TPU hardware device clocks and power are managed through Runtime PM.
System suspend and resume is known to be working - during suspend the LED
is set to off by the generic LED code.
The TPU hardware timer is equipeed with a 16-bit counter together with an
up-to-divide-by-64 prescaler which makes the hardware suitable for
brightness control. Hardware blink is unsupported.
The LED PWM waveform has been verified with a Fluke 123 Scope meter on a
sh7372 Mackerel board. Tested with experimental sh7372 A3SP power domain
patches. Platform device bind/unbind tested ok.
V2 has been tested on the DS2 LED of the sh73a0-based AG5EVM.
Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Andrew Morton <>
Mark Brown [Wed, 28 Sep 2011 00:50:42 +0000 (10:50 +1000)]
backlight: fix broken regulator API usage in l4f00242t03
The regulator support in the l4f00242t03 is very non-idiomatic. Rather
than requesting the regulators based on the device name and the supply
names used by the device the driver requires boards to pass system
specific supply names around through platform data. The driver also
conditionally requests the regulators based on this platform data, adding
unneeded conditional code to the driver.
Fix this by removing the platform data and converting to the standard
idiom, also updating all in tree users of the driver. As no datasheet
appears to be available for the LCD I'm guessing the names for the
supplies based on the existing users and I've no ability to do anything
more than compile test.
The use of regulator_set_voltage() in the driver is also problematic,
since fixed voltages are required the expectation would be that the
voltages would be fixed in the constraints set by the machines rather than
manually configured by the driver, but is less problematic.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Fabio Estevam <fabio.estevam@freescale.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <>
Wolfram Sang [Wed, 28 Sep 2011 00:50:41 +0000 (10:50 +1000)]
video/backlight: remove obsolete cleanup for clientdata
A few new i2c-drivers came into the kernel which clear the
clientdata-pointer on exit or error. This is obsolete meanwhile, the core
will do it.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Paul Mundt <lethal@linux-sh.org> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <>
Hans Verkuil [Wed, 28 Sep 2011 00:50:40 +0000 (10:50 +1000)]
poll: add poll_requested_events() function
In some cases the poll() implementation in a driver has to do different
things depending on the events the caller wants to poll for. An example
is when a driver needs to start a DMA engine if the caller polls for
POLLIN, but doesn't want to do that if POLLIN is not requested but instead
only POLLOUT or POLLPRI is requested. This is something that can happen
in the video4linux subsystem.
Unfortunately, the current epoll/poll/select implementation doesn't
provide that information reliably. The poll_table_struct does have it: it
has a key field with the event mask. But once a poll() call matches one
or more bits of that mask any following poll() calls are passed a NULL
poll_table_struct pointer.
The solution is to set the qproc field to NULL in poll_table_struct once
poll() matches the events, not the poll_table_struct pointer itself. That
way drivers can obtain the mask through a new poll_requested_events
inline.
The poll_table_struct can still be NULL since some kernel code calls it
internally (netfs_state_poll() in ./drivers/staging/pohmelfs/netfs.h). In
that case poll_requested_events() returns ~0 (i.e. all events).
Since eventpoll always leaves the key field at ~0 instead of using the
requested events mask, that source was changed as well to properly fill in
the key field.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Jonathan Corbet <corbet@lwn.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <>
WARNING: externs should be avoided in .c files
#99: FILE: arch/alpha/boot/misc.c:28:
+extern __printf(1, 2) long srm_printk(const char *, ...);
ERROR: space required after that ';' (ctx:VxV)
#178: FILE: arch/powerpc/boot/ps3.c:39:
+static inline __printf(1, 2) int DBG(const char *fmt, ...) {return 0;}
^
ERROR: "foo* bar" should be "foo *bar"
#225: FILE: arch/s390/include/asm/debug.h:175:
+debug_sprintf_event(debug_info_t* id, int level, char *string, ...);
ERROR: space required after that ',' (ctx:VxV)
#237: FILE: arch/s390/include/asm/debug.h:216:
+debug_sprintf_exception(debug_info_t *id, int level, char *string,...);
^
WARNING: space prohibited between function name and open parenthesis '('
#494: FILE: fs/ext2/ext2.h:139:
+void ext2_error (struct super_block *, const char *, const char *, ...);
WARNING: printk() should include KERN_ facility level
#719: FILE: fs/partitions/ldm.c:63:
+ printk("%s%s(): %pV\n", level, function, &vaf);
WARNING: space prohibited between function name and open parenthesis '('
#721: FILE: fs/partitions/ldm.c:65:
+ va_end (args);
WARNING: space prohibited between function name and open parenthesis '('
#750: FILE: fs/ufs/ufs.h:121:
+void ufs_warning (struct super_block *, const char *, const char *, ...);
WARNING: space prohibited between function name and open parenthesis '('
#752: FILE: fs/ufs/ufs.h:123:
+void ufs_error (struct super_block *, const char *, const char *, ...);
WARNING: space prohibited between function name and open parenthesis '('
#754: FILE: fs/ufs/ufs.h:125:
+void ufs_panic (struct super_block *, const char *, const char *, ...);
WARNING: space prohibited between function name and open parenthesis '('
#1074: FILE: include/linux/ext3_fs.h:941:
+void ext3_error (struct super_block *, const char *, const char *, ...);
WARNING: space prohibited between function name and open parenthesis '('
#1083: FILE: include/linux/ext3_fs.h:944:
+void ext3_abort (struct super_block *, const char *, const char *, ...);
WARNING: space prohibited between function name and open parenthesis '('
#1085: FILE: include/linux/ext3_fs.h:946:
+void ext3_warning (struct super_block *, const char *, const char *, ...);
WARNING: do not add new typedefs
#1178: FILE: include/linux/kdb.h:119:
+typedef __printf(1, 2) int (*kdb_printf_t)(const char *, ...);
ERROR: "foo * bar" should be "foo *bar"
#1203: FILE: include/linux/kernel.h:299:
+extern __printf(2, 3) int sprintf(char * buf, const char * fmt, ...);
William Douglas [Wed, 28 Sep 2011 00:50:39 +0000 (10:50 +1000)]
printk: remove bounds checking for log_prefix
Currently log_prefix is testing that the first character of the log level
and facility is less than '0' and greater than '9' (which is always
false).
Since the code being updated works because strtoul bombs out (endp isn't
updated) and 0 is returned anyway just remove the check and don't change
the behavior of the function.
Signed-off-by: William Douglas <william.douglas@intel.com> Signed-off-by: Andrew Morton <>
William Douglas [Wed, 28 Sep 2011 00:50:39 +0000 (10:50 +1000)]
printk: fix bounds checking for log_prefix
Currently log_prefix is testing that the first character of the log level
and facility is less than '0' and greater than '9' (which is always
false). It should be testing to see if the character less than '0' or
greater than '9' instead. This patch makes that change.
The code being changed worked because strtoul bombs out (endp isn't
updated) and 0 is returned anyway.
Signed-off-by: William Douglas <william.douglas@intel.com> Signed-off-by: Andrew Morton <>
Jason Baron [Wed, 28 Sep 2011 00:50:37 +0000 (10:50 +1000)]
dynamic_debug: fix undefined reference to `__netdev_printk'
Dynamic debug recently added support for netdev_printk. It uses
__netdev_printk() to support this functionality. However, when CONFIG_NET
is not set, we get the following error:
lib/built-in.o: In function `__dynamic_netdev_dbg':
(.text+0x9fda): undefined reference to `__netdev_printk'
Fix this by making the call to netdev_printk() contingent upon CONFIG_NET.
We could have fixed this by defining netdev_printk() to a 'no-op' in the
!CONFIG_NET case. However, this is not consistent with how the networking
layer uses netdev_printk. For example, CONFIG_NET is not set,
netdev_printk() does not have a 'no-op' definition defined.
Signed-off-by: Jason Baron <jbaron@redhat.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Greg KH <greg@kroah.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <>
Jason Baron [Wed, 28 Sep 2011 00:50:37 +0000 (10:50 +1000)]
dynamic_debug: use a single printk() to emit messages
We were using KERN_CONT to combine messages with their prefix. However,
KERN_CONT is not smp safe, in the sense that it can interleave messages.
This interleaving can result in printks coming out at the wrong loglevel.
With the high frequency of printks that dynamic debug can produce this is
not desirable.
So make dynamic_emit_prefix() fill a char buf[64] instead of doing a
printk directly. If we enable printing out of function, module, line, or
pid info, they are placed in this 64 byte buffer. In my testing 64 bytes
was enough size to fulfill all requests. Even if it's not, we can match
up the printk itself to see where it's from, so to me this is no big deal.
[akpm@linux-foundation.org: convert dangerous macro to C] Signed-off-by: Jason Baron <jbaron@redhat.com> Cc: Greg KH <greg@kroah.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <>
Mark Brown [Wed, 28 Sep 2011 00:50:35 +0000 (10:50 +1000)]
lis3lv02d: make regulator API usage unconditional
The regulator API contains a range of features for stubbing itself out
when not in use and for transparently restricting the actual effect of
regulator API calls where they can't be supported on a particular system
so that drivers don't need to individually implement this. Simplify the
driver slightly by making use of this idiom.
The only in tree user is ecovec24 which does not use the regulator API.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Éric Piel <eric.piel@tremplin-utc.net> Cc: Ilkka Koskinen <ilkka.koskinen@nokia.com> Signed-off-by: Andrew Morton <>
>From my POV, it looks like the hardware is not working as expected
and returns a bogus data rate. The driver doesn't check the result
and directly uses it as some sort of divisor in some places:
msleep(lis3->pwron_delay / lis3lv02d_get_odr());
Under this circumstances, this could very well cause the
"divide by zero" exception from above.
For now, I fixed it the easiest and most obvious way:
Check if the result is sane and if it isn't use a sane default
instead. I went for "100" in the latter case, simply because
/sys/devices/platform/lis3lv02d/rate returns it on a successful
boot.
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: Éric Piel <eric.piel@tremplin-utc.net> Cc: Matthew Garrett <mjg@redhat.com> Cc: Witold Pilat <witold.pilat@gmail.com> Cc: Lyall Pearce <lyall.pearce@hp.com> Cc: Malte Starostik <m-starostik@versanet.de> Cc: Ilkka Koskinen <ilkka.koskinen@nokia.com> Cc: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Cc: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: Andrew Morton <>
Jonathan Cameron [Wed, 28 Sep 2011 00:50:32 +0000 (10:50 +1000)]
drivers/hwmon/hwmon.c: convert idr to ida and use ida_simple_get()
A straightforward looking use of idr for a device id.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Cc: Guenter Roeck <guenter.roeck@ericsson.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Acked-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <>
Pavel Emelyanov [Wed, 28 Sep 2011 00:50:30 +0000 (10:50 +1000)]
fs/pipe.c: add ->statfs callback for pipefs
Currently a statfs on a pipe's /proc/<pid>/fd/ link returns -ENOSYS. Wire
pipfs up so that the statfs succeeds.
This is required by checkpoint-restart in the userspace to make it
possible to distinguish pipes from fifos.
When we dump information about task's open files we use the /proc/pid/fd
directoy's symlinks and the fact that opening any of them gives us exactly
the same dentry->inode pair as the original process has. Now if a task
we're dumping has opened pipe and fifo we need to detect this and act
accordingly. Knowing that an fd with type S_ISFIFO resides on a pipefs is
the most precise way.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Andrew Morton <>
Stephen Boyd [Wed, 28 Sep 2011 00:50:30 +0000 (10:50 +1000)]
Consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
The help text for this config is duplicated across the x86, parisc, and
s390 Kconfig.debug files. Arnd Bergman noted that the help text was
slightly misleading and should be fixed to state that enabling this option
isn't a problem when using pre 4.4 gcc.
To simplify the rewording, consolidate the text into lib/Kconfig.debug and
modify it there to be more explicit about when you should say N to this
config.
Also, make the text a bit more generic by stating that this option enables
compile time checks so we can cover architectures which emit warnings vs.
ones which emit errors. The details of how an architecture decided to
implement the checks isn't as important as the concept of compile time
checking of copy_from_user() calls.
While we're doing this, remove all the copy_from_user_overflow() code
that's duplicated many times and place it into lib/ so that any
architecture supporting this option can get the function for free.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Helge Deller <deller@gmx.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <>
Stephen Boyd [Wed, 28 Sep 2011 00:50:29 +0000 (10:50 +1000)]
x86: implement strict user copy checks for x86_64
Strict user copy checks are only really supported on x86_32 even though
the config option is selectable on x86_64. Add the necessary support to
the 64 bit code to trigger copy_from_user() warnings at compile time.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Andrew Morton <>
Enabling DEBUG_STRICT_USER_COPY_CHECKS causes the following warning:
In file included from arch/x86/include/asm/uaccess.h:573,
from kernel/kprobes.c:55:
In function 'copy_from_user',
inlined from 'write_enabled_file_bool' at
kernel/kprobes.c:2191:
arch/x86/include/asm/uaccess_64.h:65:
warning: call to 'copy_from_user_overflow' declared with
attribute warning: copy_from_user() buffer size is not provably
correct
presumably due to buf_size being signed causing GCC to fail to see that
buf_size can't become negative.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S. Miller <davem@davemloft.net> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Andrew Morton <>
Shaohua Li [Wed, 28 Sep 2011 00:50:28 +0000 (10:50 +1000)]
intel_idle: fix API misuse
smp_call_function() only lets all other CPUs execute a specific function,
while we expect all CPUs do in intel_idle. Without the fix, we could have
one cpu which has auto_demotion enabled or has no boradcast timer setup.
Usually we don't see impact because auto demotion just harms power and the
intel_idle init is called in CPU 0, where boradcast timer delivers
interrupt, but this still could be a problem.
Signed-off-by: Shaohua Li <shaohua.li@intel.com> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <>
Michael Cree [Wed, 28 Sep 2011 00:50:28 +0000 (10:50 +1000)]
alpha: wire up sendmmsg syscall
Signed-off-by: Michael Cree <mcree@orcon.net.nz> Reviewed-by: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Andrew Morton <>
Michael Cree [Wed, 28 Sep 2011 00:50:27 +0000 (10:50 +1000)]
alpha: wire up accept4 syscall
Somehow wiring up the accept4 syscall on Alpha was missed long ago.
This commit rectifies that oversight.
Signed-off-by: Michael Cree <mcree@orcon.net.nz> Reviewed-by: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Andrew Morton <>
Magnus Lynch [Wed, 28 Sep 2011 00:50:27 +0000 (10:50 +1000)]
hpet: factor timer allocate from open
The current implementation of the /dev/hpet driver couples opening the
device with allocating one of the (scarce) timers (aka comparators). This
is a limitation in that the main counter may be valuable to applications
seeking a high-resolution timer who have no use for the interrupt
generating functionality of the comparators.
This patch alters the open semantics so that when the device is opened, no
timer is allocated. Operations that depend on a timer being in context
implicitly attempt allocating a timer, to maintain backward compatibility.
There is also an IOCTL (HPET_ALLOC_TIMER _IO) added so that the
allocation may be done explicitly. (I prefer the explicit open then
allocate pattern but don't know how practical it would be to require all
existing code to be changed.)
/dev/hpet is accessed via mmap(). This is the only interface of /dev/hpet
that is actually used in practice.
[akpm@linux-foundation.org: coding-style tweaks]
[arnd@arndb.de: fix build] Signed-off-by: Magnus Lynch <maglyx@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Acked-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <>
Andy Shevchenko [Wed, 28 Sep 2011 00:50:26 +0000 (10:50 +1000)]
selinuxfs: remove custom hex_to_bin()
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Eric Paris <eparis@parisplace.org> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <>
Kautuk Consul [Wed, 28 Sep 2011 00:50:26 +0000 (10:50 +1000)]
vmscan.c: fix invalid strict_strtoul() check in write_scan_unevictable_node()
write_scan_unevictable_node() checks the value req returned by
strict_strtoul() and returns 1 if req is 0.
However, when strict_strtoul() returns 0, it means successful conversion
of buf to unsigned long.
Due to this, the function was not proceeding to scan the zones for
unevictable pages even though we write a valid value to the
scan_unevictable_pages sys file.
Change this check slightly to check for invalid value in buf as well as 0
value stored in res after successful conversion via strict_strtoul. In
both cases, we do not perform the scanning of this node's zones.
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <>
Dean Nelson [Wed, 28 Sep 2011 00:50:25 +0000 (10:50 +1000)]
HWPOISON: convert pr_debug()s to pr_info()s
Commit fb46e73520940b ("HWPOISON: Convert pr_debugs to pr_info) authored
by Andi Kleen converted a number of pr_debug()s to pr_info()s.
About the same time additional code with pr_debug()s was added by two
other commits 8c6c2ecb4466 ("HWPOSION, hugetlb: recover from free hugepage
error when !MF_COUNT_INCREASED") and d950b95882f3d ("HWPOISON, hugetlb:
soft offlining for hugepage"). And these pr_debug()s failed to get
converted to pr_info()s.
This patch converts them as well. And does some minor related whitespace
cleanup.
Signed-off-by: Dean Nelson <dnelson@redhat.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <>
Tao Ma [Wed, 28 Sep 2011 00:50:24 +0000 (10:50 +1000)]
fs/buffer.c: add device information for error output in __find_get_block_slow()
On the ext4 mailing list[1], we got some report about errors in
__find_get_block_slow(), but the information is very limited.
If the device information is given, we can know the name of the sick
volume. Futhermore, we can get the corresponding status of that
block(group, inode block etc) by analyzing the disk layout.
Andrea Arcangeli [Wed, 28 Sep 2011 00:50:22 +0000 (10:50 +1000)]
thp-tail-page-refcounting-fix-6
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Michel Lespinasse <walken@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <>
Andrea Arcangeli [Wed, 28 Sep 2011 00:50:22 +0000 (10:50 +1000)]
mm: thp: tail page refcounting fix
Michel while working on the working set estimation code, noticed that
calling get_page_unless_zero() on a random pfn_to_page(random_pfn) wasn't
safe, if the pfn ended up being a tail page of a transparent hugepage
under splitting by __split_huge_page_refcount(). He then found the
problem could also theoretically materialize with
page_cache_get_speculative() during the speculative radix tree lookups
that uses get_page_unless_zero() in SMP if the radix tree page is freed
and reallocated and get_user_pages is called on it before
page_cache_get_speculative has a chance to call get_page_unless_zero().
So the best way to fix the problem is to keep page_tail->_count zero at
all times. This will guarantee that get_page_unless_zero() can never
succeed on any tail page. page_tail->_mapcount is guaranteed zero and is
unused for all tail pages of a compound page, so we can simply account the
tail page references there and transfer them to tail_page->_count in
__split_huge_page_refcount() (in addition to the head_page->_mapcount).
While debugging this s/_count/_mapcount/ change I also noticed get_page is
called by direct-io.c on pages returned by get_user_pages. That wasn't
entirely safe because the two atomic_inc in get_page weren't atomic. As
opposed other get_user_page users like secondary-MMU page fault to
establish the shadow pagetables would never call any superflous get_page
after get_user_page returns. It's safer to make get_page universally safe
for tail pages and to use get_page_foll() within follow_page (inside
get_user_pages()). get_page_foll() is safe to do the refcounting for tail
pages without taking any locks because it is run within PT lock protected
critical sections (PT lock for pte and page_table_lock for
pmd_trans_huge). The standard get_page() as invoked by direct-io instead
will now take the compound_lock but still only for tail pages. The
direct-io paths are usually I/O bound and the compound_lock is per THP so
very finegrined, so there's no risk of scalability issues with it. A
simple direct-io benchmarks with all lockdep prove locking and spinlock
debugging infrastructure enabled shows identical performance and no
overhead. So it's worth it. Ideally direct-io should stop calling
get_page() on pages returned by get_user_pages(). The spinlock in
get_page() is already optimized away for no-THP builds but doing
get_page() on tail pages returned by GUP is generally a rare operation and
usually only run in I/O paths.
This new refcounting on page_tail->_mapcount in addition to avoiding new
RCU critical sections will also allow the working set estimation code to
work without any further complexity associated to the tail page
refcounting with THP.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Michel Lespinasse <walken@google.com> Reviewed-by: Michel Lespinasse <walken@google.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <>
All the fixes suggested by Andrew Morton. Not much of a changelog
since the patch should probably be folded into
mm-add-extra-free-kbytes-tunable.patch
Thank you for pointing these out, Andrew.
Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <>
Add a userspace visible knob to tell the VM to keep an extra amount of
memory free, by increasing the gap between each zone's min and low
watermarks.
This is useful for realtime applications that call system calls and have a
bound on the number of allocations that happen in any short time period.
In this application, extra_free_kbytes would be left at an amount equal to
or larger than than the maximum number of allocations that happen in any
burst.
It may also be useful to reduce the memory use of virtual machines
(temporarily?), in a way that does not cause memory fragmentation like
ballooning does.
Signed-off-by: Rik van Riel<riel@redhat.com> Signed-off-by: Andrew Morton <>
After commit v2.6.36-5896-gd065bd8 "mm: retry page fault when blocking on
disk transfer" we usually wait in page-faults without mmap_sem held, so
all swap-token logic was broken, because it based on using
rwsem_is_locked(&mm->mmap_sem) as sign of in progress page-faults.
Add an atomic counter of in progress page-faults for mm to the mm_struct
with swap-token.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <>
kswapd: assign new_order and new_classzone_idx after wakeup in sleeping
There 2 places to read pgdat in kswapd. One is return from a successful
balance, another is waked up from kswapd sleeping. The new_order and
new_classzone_idx represent the balance input order and classzone_idx.
But current new_order and new_classzone_idx are not assigned after
kswapd_try_to_sleep(), that will cause a bug in the following scenario.
1: after a successful balance, kswapd goes to sleep, and new_order = 0;
new_classzone_idx = __MAX_NR_ZONES - 1;
2: kswapd waked up with order = 3 and classzone_idx = ZONE_NORMAL
3: in the balance_pgdat() running, a new balance wakeup happened with
order = 5, and classzone_idx = ZONE_NORMAL
4: the first wakeup(order = 3) finished successufly, return order = 3
but, the new_order is still 0, so, this balancing will be treated as a
failed balance. And then the second tighter balancing will be missed.
So, to avoid the above problem, the new_order and new_classzone_idx need
to be assigned for later successful comparison.
Signed-off-by: Alex Shi <alex.shi@intel.com> Acked-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Tested-by: Pádraig Brady <P@draigBrady.com> Signed-off-by: Andrew Morton <>
Minchan Kim [Wed, 28 Sep 2011 00:50:19 +0000 (10:50 +1000)]
mm: compaction: accounting fix
I saw the following accouting of compaction during test of the series.
compact_blocks_moved 251
compact_pages_moved 44
It's very awkward to me although it's possbile because it means we try to
compact 251 blocks but it just migrated 44 pages. As further
investigation, I found isolate_migratepages doesn't isolate any pages but
it returns ISOLATE_SUCCESS and then, it just increases
compact_blocks_moved but doesn't increased compact_pages_moved.
This patch makes accouting of compaction works only in case of success of
isolation.
Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <>
Minchan Kim [Wed, 28 Sep 2011 00:50:18 +0000 (10:50 +1000)]
mm: compaction: compact unevictable pages
Presently compaction doesn't handle mlocked pages as it uses
__isolate_lru_page which doesn't consider unevicatable pages. It is used
by just lumpy so it is pointless that it isolates unevictable pages.
But the situation has changed. Compaction can handle unevictable pages
and it can help getting big contiguos pages in memory whcih is fragmented
by many pinned pages with mlock.
I tested this patch with following scenario.
1. A : allocate 80% anon pages in system
2. B : allocate 20% mlocked page in system
/* Maybe, mlocked pages are located in low pfn address */
3. kill A /* high pfn address are free */
4. echo 1 > /proc/sys/vm/compact_memory
old:
compact_blocks_moved 251
compact_pages_moved 44
new:
compact_blocks_moved 258
compact_pages_moved 412
Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <jweiner@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <>
This patch adds helper free_hot_cold_page_list() to free list of 0-order
pages. It frees pages directly from list without temporary page-vector.
It also calls trace_mm_pagevec_free() to simulate pagevec_free()
behaviour.
kswapd: avoid unnecessary rebalance after an unsuccessful balancing
In commit 215ddd66 ("mm: vmscan: only read new_classzone_idx from pgdat
when reclaiming successfully") , Mel Gorman said kswapd is better to sleep
after a unsuccessful balancing if there is tighter reclaim request pending
in the balancing. But in the following scenario, kswapd do something that
is not matched our expectation. The patch fixes this issue.
1, Read pgdat request A (classzone_idx, order = 3)
2, balance_pgdat()
3, During pgdat, a new pgdat request B (classzone_idx, order = 5) is placed
4, balance_pgdat() returns but failed since returned order = 0
5, pgdat of request A assigned to balance_pgdat(), and do balancing again.
While the expectation behavior of kswapd should try to sleep.
Signed-off-by: Alex Shi <alex.shi@intel.com> Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com> Acked-by: Mel Gorman <mgorman@suse.de> Tested-by: Pádraig Brady <P@draigBrady.com> Cc: Rik van Riel <riel@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <>
Joe Perches [Wed, 28 Sep 2011 00:50:16 +0000 (10:50 +1000)]
mm: neaten warn_alloc_failed
Add __attribute__((format (printf...) to the function to validate format
and arguments. Use vsprintf extension %pV to avoid any possible message
interleaving. Coalesce format string. Convert printks/pr_warning to
pr_warn.
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <>
Jeff Layton [Wed, 28 Sep 2011 00:50:15 +0000 (10:50 +1000)]
mm: iov_iter: have iov_iter_advance() decrement nr_segs appropriately
Currently, when you call iov_iter_advance, then the pointer to the iovec
array can be incremented, but it does not decrement the nr_segs value in
the iov_iter struct. The result is a iov_iter struct with a nr_segs value
that goes beyond the end of the array.
While I'm not aware of anything that's specifically broken by this, it
seems odd and a bit dangerous not to decrement that value. If someone
were to trust the nr_segs value to be correct, then they could end up
walking off the end of the array.
Changing this might also provide some micro-optimization when dealing with
the last iovec in an array. Many of the other routines that deal with
iov_iter have optimized codepaths when nr_segs == 1.
Signed-off-by: Jeff Layton <jlayton@redhat.com> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <>
Sonic Zhang [Wed, 28 Sep 2011 00:50:15 +0000 (10:50 +1000)]
include/asm-generic/page.h: calculate virt_to_page and page_to_virt via predefined macro
On NOMMU architectures, if physical memory doesn't start from 0,
ARCH_PFN_OFFSET is defined to generate page index in mem_map array.
Because virtual address is equal to physical address, PAGE_OFFSET is
always 0. virt_to_page and page_to_virt should not index page by
PAGE_OFFSET directly.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Cc: Greg Ungerer <gerg@snapgear.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <>
thp_split 0 confirms no thp split despite plenty of hugepages allocated.
The measurement of only the mremap time (so excluding the 3 long
memset and final long 10GB memory accessing memcmp):
THP on
usec 14824
usec 14862
usec 14859
THP off
usec 256416
usec 255981
usec 255847
With an older kernel without the mremap optimizations (the below patch
optimizes the non THP version too).
THP on
usec 392107
usec 390237
usec 404124
THP off
usec 444294
usec 445237
usec 445820
I guess with a threaded program that sends more IPI on large SMP it'd
create an even larger difference.
All debug options are off except DEBUG_VM to avoid skewing the
results.
The only problem for native 2M mremap like it happens above both the
source and destination address must be 2M aligned or the hugepmd can't be
moved without a split but that is an hardware limitation.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Johannes Weiner <jweiner@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <>
Andrea Arcangeli [Wed, 28 Sep 2011 00:50:13 +0000 (10:50 +1000)]
mremap: avoid sending one IPI per page
This replaces ptep_clear_flush() with ptep_get_and_clear() and a single
flush_tlb_range() at the end of the loop, to avoid sending one IPI for
each page.
The mmu_notifier_invalidate_range_start/end section is enlarged
accordingly but this is not going to fundamentally change things. It was
more by accident that the region under mremap was for the most part still
available for secondary MMUs: the primary MMU was never allowed to
reliably access that region for the duration of the mremap (modulo
trapping SIGSEGV on the old address range which sounds unpractical and
flakey). If users wants secondary MMUs not to lose access to a large
region under mremap they should reduce the mremap size accordingly in
userland and run multiple calls. Overall this will run faster so it's
actually going to reduce the time the region is under mremap for the
primary MMU which should provide a net benefit to apps.
For KVM this is a noop because the guest physical memory is never
mremapped, there's just no point it ever moving it while guest runs. One
target of this optimization is JVM GC (so unrelated to the mmu notifier
logic).
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Johannes Weiner <jweiner@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <>
Andrea Arcangeli [Wed, 28 Sep 2011 00:50:13 +0000 (10:50 +1000)]
mremap: check for overflow using deltas
Using "- 1" relies on the old_end to be page aligned and PAGE_SIZE > 1,
those are reasonable requirements but the check remains obscure and it
looks more like an off by one error than an overflow check. This I feel
will improve readability.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Johannes Weiner <jweiner@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <>
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