Davide Libenzi [Fri, 11 May 2007 05:23:21 +0000 (22:23 -0700)]
signal/timer/event: KAIO eventfd support example
This is an example about how to add eventfd support to the current KAIO code,
in order to enable KAIO to post readiness events to a pollable fd (hence
compatible with POSIX select/poll). The KAIO code simply signals the eventfd
fd when events are ready, and this triggers a POLLIN in the fd. This patch
uses a reserved for future use member of the struct iocb to pass an eventfd
file descriptor, that KAIO will use to post events every time a request
completes. At that point, an aio_getevents() will return the completed result
to a struct io_event. I made a quick test program to verify the patch, and it
runs fine here:
http://www.xmailserver.org/eventfd-aio-test.c
The test program uses poll(2), but it'd, of course, work with select and epoll
too.
This can allow to schedule both block I/O and other poll-able devices
requests, and wait for results using select/poll/epoll. In a typical
scenario, an application would submit KAIO request using aio_submit(), and
will also use epoll_ctl() on the whole other class of devices (that with the
addition of signals, timers and user events, now it's pretty much complete),
and then would:
Davide Libenzi [Fri, 11 May 2007 05:23:19 +0000 (22:23 -0700)]
signal/timer/event: eventfd core
This is a very simple and light file descriptor, that can be used as event
wait/dispatch by userspace (both wait and dispatch) and by the kernel
(dispatch only). It can be used instead of pipe(2) in all cases where those
would simply be used to signal events. Their kernel overhead is much lower
than pipes, and they do not consume two fds. When used in the kernel, it can
offer an fd-bridge to enable, for example, functionalities like KAIO or
syslets/threadlets to signal to an fd the completion of certain operations.
But more in general, an eventfd can be used by the kernel to signal readiness,
in a POSIX poll/select way, of interfaces that would otherwise be incompatible
with it. The API is:
int eventfd(unsigned int count);
The eventfd API accepts an initial "count" parameter, and returns an eventfd
fd. It supports poll(2) (POLLIN, POLLOUT, POLLERR), read(2) and write(2).
The POLLIN flag is raised when the internal counter is greater than zero.
The POLLOUT flag is raised when at least a value of "1" can be written to the
internal counter.
The POLLERR flag is raised when an overflow in the counter value is detected.
The write(2) operation can never overflow the counter, since it blocks (unless
O_NONBLOCK is set, in which case -EAGAIN is returned).
But the eventfd_signal() function can do it, since it's supposed to not sleep
during its operation.
The read(2) function reads the __u64 counter value, and reset the internal
value to zero. If the value read is equal to (__u64) -1, an overflow happened
on the internal counter (due to 2^64 eventfd_signal() posts that has never
been retired - unlickely, but possible).
The write(2) call writes an __u64 count value, and adds it to the current
counter. The eventfd fd supports O_NONBLOCK also.
On the kernel side, we have:
struct file *eventfd_fget(int fd);
int eventfd_signal(struct file *file, unsigned int n);
The eventfd_fget() should be called to get a struct file* from an eventfd fd
(this is an fget() + check of f_op being an eventfd fops pointer).
The kernel can then call eventfd_signal() every time it wants to post an event
to userspace. The eventfd_signal() function can be called from any context.
An eventfd() simple test and bench is available here:
http://www.xmailserver.org/eventfd-bench.c
This is the eventfd-based version of pipetest-4 (pipe(2) based):
http://www.xmailserver.org/pipetest-4.c
Not that performance matters much in the eventfd case, but eventfd-bench
shows almost as double as performance than pipetest-4.
Davide Libenzi [Fri, 11 May 2007 05:23:16 +0000 (22:23 -0700)]
signal/timer/event: timerfd core
This patch introduces a new system call for timers events delivered though
file descriptors. This allows timer event to be used with standard POSIX
poll(2), select(2) and read(2). As a consequence of supporting the Linux
f_op->poll subsystem, they can be used with epoll(2) too.
The system call is defined as:
int timerfd(int ufd, int clockid, int flags, const struct itimerspec *utmr);
The "ufd" parameter allows for re-use (re-programming) of an existing timerfd
w/out going through the close/open cycle (same as signalfd). If "ufd" is -1,
s new file descriptor will be created, otherwise the existing "ufd" will be
re-programmed.
The "clockid" parameter is either CLOCK_MONOTONIC or CLOCK_REALTIME. The time
specified in the "utmr->it_value" parameter is the expiry time for the timer.
If the TFD_TIMER_ABSTIME flag is set in "flags", this is an absolute time,
otherwise it's a relative time.
If the time specified in the "utmr->it_interval" is not zero (.tv_sec == 0,
tv_nsec == 0), this is the period at which the following ticks should be
generated.
The "utmr->it_interval" should be set to zero if only one tick is requested.
Setting the "utmr->it_value" to zero will disable the timer, or will create a
timerfd without the timer enabled.
The function returns the new (or same, in case "ufd" is a valid timerfd
descriptor) file, or -1 in case of error.
As stated before, the timerfd file descriptor supports poll(2), select(2) and
epoll(2). When a timer event happened on the timerfd, a POLLIN mask will be
returned.
The read(2) call can be used, and it will return a u32 variable holding the
number of "ticks" that happened on the interface since the last call to
read(2). The read(2) call supportes the O_NONBLOCK flag too, and EAGAIN will
be returned if no ticks happened.
A quick test program, shows timerfd working correctly on my amd64 box:
http://www.xmailserver.org/timerfd-test.c
[akpm@linux-foundation.org: add sys_timerfd to sys_ni.c] Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davide Libenzi [Fri, 11 May 2007 05:23:13 +0000 (22:23 -0700)]
signal/timer/event: signalfd core
This patch series implements the new signalfd() system call.
I took part of the original Linus code (and you know how badly it can be
broken :), and I added even more breakage ;) Signals are fetched from the same
signal queue used by the process, so signalfd will compete with standard
kernel delivery in dequeue_signal(). If you want to reliably fetch signals on
the signalfd file, you need to block them with sigprocmask(SIG_BLOCK). This
seems to be working fine on my Dual Opteron machine. I made a quick test
program for it:
http://www.xmailserver.org/signafd-test.c
The signalfd() system call implements signal delivery into a file descriptor
receiver. The signalfd file descriptor if created with the following API:
int signalfd(int ufd, const sigset_t *mask, size_t masksize);
The "ufd" parameter allows to change an existing signalfd sigmask, w/out going
to close/create cycle (Linus idea). Use "ufd" == -1 if you want a brand new
signalfd file.
The "mask" allows to specify the signal mask of signals that we are interested
in. The "masksize" parameter is the size of "mask".
The signalfd fd supports the poll(2) and read(2) system calls. The poll(2)
will return POLLIN when signals are available to be dequeued. As a direct
consequence of supporting the Linux poll subsystem, the signalfd fd can use
used together with epoll(2) too.
The read(2) system call will return a "struct signalfd_siginfo" structure in
the userspace supplied buffer. The return value is the number of bytes copied
in the supplied buffer, or -1 in case of error. The read(2) call can also
return 0, in case the sighand structure to which the signalfd was attached,
has been orphaned. The O_NONBLOCK flag is also supported, and read(2) will
return -EAGAIN in case no signal is available.
If the size of the buffer passed to read(2) is lower than sizeof(struct
signalfd_siginfo), -EINVAL is returned. A read from the signalfd can also
return -ERESTARTSYS in case a signal hits the process. The format of the
struct signalfd_siginfo is, and the valid fields depends of the (->code &
__SI_MASK) value, in the same way a struct siginfo would:
Davide Libenzi [Fri, 11 May 2007 05:23:11 +0000 (22:23 -0700)]
signal/timer/event fds: anonymous inode source
This patch add an anonymous inode source, to be used for files that need
and inode only in order to create a file*. We do not care of having an
inode for each file, and we do not even care of having different names in
the associated dentries (dentry names will be same for classes of file*).
This allow code reuse, and will be used by epoll, signalfd and timerfd
(and whatever else there'll be).
Make autofs container-friendly by caching struct pid reference rather than
pid_t and using pid_nr() to retreive a task's pid_t.
ChangeLog:
- Fix Eric Biederman's comments - Use find_get_pid() to hold a
reference to oz_pgrp and release while unmounting; separate out
changes to autofs and autofs4.
- Fix Cedric's comments: retain old prototype of parse_options()
and move necessary change to its caller.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: containers@lists.osdl.org Acked-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Modify copy_process() to take a struct pid * parameter instead of a pid_t.
This simplifies the code a bit and also avoids having to call find_pid() to
convert the pid_t to a struct pid.
Changelog:
- Fixed Badari Pulavarty's comments and passed in &init_struct_pid
from fork_idle().
- Fixed Eric Biederman's comments and simplified this patch and
used a new patch to remove the likely(pid) check.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: <containers@lists.osdl.org> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Statically initialize a struct pid for the swapper process (pid_t == 0) and
attach it to init_task. This is needed so task_pid(), task_pgrp() and
task_session() interfaces work on the swapper process also.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: <containers@lists.osdl.org> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
attach_pid() currently takes a pid_t and then uses find_pid() to find the
corresponding struct pid. Sometimes we already have the struct pid. We can
then skip find_pid() if attach_pid() were to take a struct pid parameter.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: <containers@lists.osdl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Paul Fulghum [Fri, 11 May 2007 05:22:50 +0000 (22:22 -0700)]
tty: add compat_ioctl
Add compat_ioctl method for tty code to allow processing of 32 bit ioctl
calls on 64 bit systems by tty core, tty drivers, and line disciplines.
Based on patch by Arnd Bergmann:
http://www.uwsg.iu.edu/hypermail/linux/kernel/0511.0/1732.html
[akpm@linux-foundation.org: make things static] Signed-off-by: Paul Fulghum <paulkf@microgate.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rene Herman [Fri, 11 May 2007 05:22:50 +0000 (22:22 -0700)]
module_author: don't advise putting in an email address
module_author: don't advise putting in an email address
It's information that's easily outdated and easily mistaken for a driver
contact which is a problem especially for modules with multiple current and
non-current authors as well as for modules with a maintainer who may not
even be a module author.
Signed-off-by: Rene Herman <rene.herman@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a call to hard_irq_disable() to stop_machine so that we make sure IRQs are
really disabled and not only lazy-disabled on archs like powerpc as some users
of stop_machine() may rely on that.
[akpm@linux-foundation.org: build fix] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some architectures, like powerpc, implement lazy disabling of interrupts.
That means that on those, local_irq_disable() doesn't actually disable
interrupts on the CPU, but only sets some per CPU flag which cause them to be
disabled only if an interrupt actually occurs.
However, in some cases, such as stop_machine, we really want interrupts to be
fully disabled. For example, I have code using stop machine to do ECC error
injection, used to verify operations of the ECC hardware, that sort of thing.
It really needs to make sure that nothing is actually writing to memory while
the injection happens. Similar examples can be found in other low level bits
and pieces.
This patch implements a generic hard_irq_disable() function which is meant to
be called -after- local_irq_disable() and ensures that interrupts are fully
disabled on that CPU. The default implementation is a nop, though powerpc
does already provide an appropriate one.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch renames the raw hard_irq_{enable,disable} into
__hard_irq_{enable,disable} and introduces a higher level hard_irq_disable()
function that can be used by any code to enforce that IRQs are fully disabled,
not only lazy disabled.
The difference with the __ versions is that it will update some per-processor
fields so that the kernel keeps track and properly re-enables them in the next
local_irq_disable();
This prepares powerpc for my next patch that introduces hard_irq_disable()
generically.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stephen Rothwell [Fri, 11 May 2007 05:22:40 +0000 (22:22 -0700)]
Consolidate asm/poll.h
These files are almost all the same.
This patch could be made even simpler if we don't mind POLLREMOVE turning
up in a few architectures that didn't have it previously (which should be
OK as POLLREMOVE is not used anywhere in the current tree).
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Fri, 11 May 2007 05:22:39 +0000 (22:22 -0700)]
lib/hexdump
Based on ace_dump_mem() from Grant Likely for the Xilinx SystemACE
CompactFlash interface.
Add print_hex_dump() & hex_dumper() to lib/hexdump.c and linux/kernel.h.
This patch adds the functions print_hex_dump() & hex_dumper().
print_hex_dump() can be used to perform a hex + ASCII dump of data to
syslog, in an easily viewable format, thus providing a common text hex dump
format.
hex_dumper() provides a dump-to-memory function. It converts one "line" of
output (16 bytes of input) at a time.
Example usages:
print_hex_dump(KERN_DEBUG, DUMP_PREFIX_ADDRESS, frame->data, frame->len);
hex_dumper(frame->data, frame->len, linebuf, sizeof(linebuf));
Eric Dumazet [Fri, 11 May 2007 05:22:37 +0000 (22:22 -0700)]
getrusage(): fill ru_inblock and ru_oublock fields if possible
If CONFIG_TASK_IO_ACCOUNTING is defined, we update io accounting counters for
each task.
This patch permits reporting of values using the well known getrusage()
syscall, filling ru_inblock and ru_oublock instead of null values.
As TASK_IO_ACCOUNTING currently counts bytes counts, we approximate blocks
count doing : nr_blocks = nr_bytes / 512
Example of use :
----------------------
After patch is applied, /usr/bin/time command can now give a good
approximation of IO that the process had to do.
$ /usr/bin/time grep tototo /usr/include/*
Command exited with non-zero status 1
0.00user 0.02system 0:02.11elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k
24288inputs+0outputs (0major+259minor)pagefaults 0swaps
Jeff Dike [Fri, 11 May 2007 05:22:35 +0000 (22:22 -0700)]
uml: shrink kernel stacks
Make kernel stacks be 1 page on i386 and 2 pages on x86_64. These match the
host values.
Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Dike [Fri, 11 May 2007 05:22:34 +0000 (22:22 -0700)]
uml: iRQ stacks
Add a separate IRQ stack. This differs from i386 in having the entire
interrupt run on a separate stack rather than starting on the normal kernel
stack and switching over once some preparation has been done. The underlying
mechanism, is of course, sigaltstack.
Another difference is that interrupts that happen in userspace are handled on
the normal kernel stack. These cause a wait wakeup instead of a signal
delivery so there is no point in trying to switch stacks for these. There's
no other stuff on the stack, so there is no extra stack consumption.
This quirk makes it possible to have the entire interrupt run on a separate
stack - process preemption (and calls to schedule()) happens on a normal
kernel stack. If we enable CONFIG_PREEMPT, this will need to be rethought.
The IRQ stack for CPU 0 is declared in the same way as the initial kernel
stack. IRQ stacks for other CPUs will be allocated dynamically.
An extra field was added to the thread_info structure. When the active
thread_info is copied to the IRQ stack, the real_thread field points back to
the original stack. This makes it easy to tell where to copy the thread_info
struct back to when the interrupt is finished. It also serves as a marker of
a nested interrupt. It is NULL for the first interrupt on the stack, and
non-NULL for any nested interrupts.
Care is taken to behave correctly if a second interrupt comes in when the
thread_info structure is being set up or taken down. I could just disable
interrupts here, but I don't feel like giving up any of the performance gained
by not flipping signals on and off.
If an interrupt comes in during these critical periods, the handler can't run
because it has no idea what shape the stack is in. So, it sets a bit for its
signal in a global mask and returns. The outer handler will deal with this
signal itself.
Atomicity is had with xchg. A nested interrupt that needs to bail out will
xchg its signal mask into pending_mask and repeat in case yet another
interrupt hit at the same time, until the mask stabilizes.
The outermost interrupt will set up the thread_info and xchg a zero into
pending_mask when it is done. At this point, nested interrupts will look at
->real_thread and see that no setup needs to be done. They can just continue
normally.
Similar care needs to be taken when exiting the outer handler. If another
interrupt comes in while it is copying the thread_info, it will drop a bit
into pending_mask. The outer handler will check this and if it is non-zero,
will loop, set up the stack again, and handle the interrupt.
Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Dike [Fri, 11 May 2007 05:22:32 +0000 (22:22 -0700)]
uml: tidy IRQ code
Some tidying of the irq code before introducing irq stacks. Mostly
style fixes, but the timer handler calls the timer code directly
rather than going through the generic sig_handler_common_skas.
Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Dike [Fri, 11 May 2007 05:22:31 +0000 (22:22 -0700)]
uml: use UM_THREAD_SIZE in userspace code
Now that we have UM_THREAD_SIZE, we can replace the calculations in
user-space code (an earlier patch took care of the kernel side of the
house).
Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Dike [Fri, 11 May 2007 05:22:30 +0000 (22:22 -0700)]
uml: remove task_protections
Replaced task_protections with stack_protections since they do the same
thing, and task_protections was misnamed anyway.
This needs THREAD_SIZE, so that's imported via common-offsets.h
Also tidied up the code in the vicinity.
Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hirokazu Takata [Fri, 11 May 2007 05:22:28 +0000 (22:22 -0700)]
m32r: fix pte_to_pgoff(), pgoff_to_pte() and __swp_type() macros
This patch is required to handle file-mapped or swapped-out pages
correctly.
- Fix pte_to_pgoff() and pgoff_to_pte() macros not to include
_PAGE_PROTNONE bit of PTE.
Mask value for { ACCESSED, N, (R, W, X), L, G } is not 0xef but 0x7f.
- Fix __swp_type() macro for MAX_SWAPFILES_SHIFT(=5), which is defined
in include/linux/swap.h.
Hirokazu Takata [Fri, 11 May 2007 05:22:25 +0000 (22:22 -0700)]
m32r: fix switch_to macro to push/pop frame pointer if needed
This patch fixes a rarely-happened but severe scheduling problem of
the recent m32r kernel of 2.6.17-rc3 or later.
In the following previous m32r patch, the switch_to macro was
modified not to do unnecessary push/pop operations for tuning.
> [PATCH] m32r: update switch_to macro for tuning
> 4127272c38619c56f0c1aa01d01c7bd757db70a1
In this modification, only 'lr' and 'sp' registers are push/pop'ed,
assuming that the m32r kernel is always compiled with
-fomit-frame-pointer option.
However, in 2.6 kernel, kernel/sched.c is irregularly compiled
with -fno-omit-frame-pointer if CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER
is not defined.
-- kernel/Makefile --
:
ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
# needed for x86 only. Why this used to be enabled for all architectures is beyond
# me. I suspect most platforms don't need this, but until we know that for sure
# I turn this off for IA-64 only. Andreas Schwab says it's also needed on m68k
# to get a correct value for the wait-channel (WCHAN in ps). --davidm
CFLAGS_sched.o := $(PROFILING) -fno-omit-frame-pointer
endif
:
---
Therefore, for the recent m32r kernel, we have to push/pop 'fp'
(frame pointer) if CONFIG_FRAME_POINTER is defined or
CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER is not defined.
VM statistics updates do not matter if the kernel is in idle powersaving
mode. So allow the timer to be deferred.
It would be better though if we could switch the timer between deferrable
and nondeferrable based on differentials present. The timer would start
out nondeferrable and if we find that there were no updates in the last
statistics interval then we would switch the timer to deferrable. If the
timer later finds again that there are differentials then go to
nondeferrable again.
And yet another way would be to run the timer shortly before going to idle?
The solution here means that the VM counters may be slightly off during
idle since differentials may be still pending while the timer is deferred.
Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Howells [Fri, 11 May 2007 05:22:20 +0000 (22:22 -0700)]
AFS: fix a couple of problems with unlinking AFS files
Fix a couple of problems with unlinking AFS files.
(1) The parent directory wasn't being updated properly between unlink() and
the following lookup().
It seems that, for some reason, invalidate_remote_inode() wasn't
discarding the directory contents correctly, so this patch calls
invalidate_inode_pages2() instead on non-regular files.
(2) afs_vnode_deleted_remotely() should handle vnodes that don't have a
source server recorded without oopsing.
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Howells [Fri, 11 May 2007 05:22:19 +0000 (22:22 -0700)]
AFS: fix interminable loop in afs_write_back_from_locked_page()
Following bug was uncovered by compiling with '-W' flag:
CC [M] fs/afs/write.o
fs/afs/write.c: In function â\80\98afs_write_back_from_locked_pageâ\80\99:
fs/afs/write.c:398: warning: comparison of unsigned expression >= 0 is always true
Loop variable 'n' is unsigned, so wraps around happily as far as I can
see. Trival fix attached (compile tested only).
Signed-off-by: Mika Kukkonen <mikukkon@iki.fi> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Brownell [Fri, 11 May 2007 05:22:17 +0000 (22:22 -0700)]
Documentation/gpio.txt mentions GENERIC_GPIO
Documentation/gpio.txt should mention the Kconfig GENERIC_GPIO flag, for
platforms to declare when relevant. This should help minimize goofs like
omitting it, or not depending on it when needed.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mika Kukkonen [Fri, 11 May 2007 05:22:17 +0000 (22:22 -0700)]
Bug in mm/thrash.c function grab_swap_token()
Following bug was uncovered by compiling with '-W' flag:
CC mm/thrash.o
mm/thrash.c: In function â\80\98grab_swap_tokenâ\80\99:
mm/thrash.c:52: warning: comparison of unsigned expression < 0 is always false
Variable token_priority is unsigned, so decrementing first and then
checking the result does not work; fixed by reversing the test, patch
attached (compile tested only).
I am not sure if likely() makes much sense in this new situation, but
I'll let somebody else to make a decision on that.
Signed-off-by: Mika Kukkonen <mikukkon@iki.fi> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vivek Goyal [Fri, 11 May 2007 05:22:15 +0000 (22:22 -0700)]
x86_64: display more intuitive error message if kernel is not 2MB aligned
o x86_64 kernel needs to be compiled for 2MB aligned addresses. Currently
we are using BUILD_BUG_ON() to warn the user if he has not done so. But
looks like folks are not finding message very intutive and don't open
the respective c file to find problem source. (Bug 8439)
arch/x86_64/kernel/head64.c: In function 'x86_64_start_kernel':
arch/x86_64/kernel/head64.c:70: error: size of array 'type name' is negative
o Using preprocessor directive #error to print a better message if
CONFIG_PHYSICAL_START is not aligned to 2MB boundary.
Joerg Roedel [Fri, 11 May 2007 05:22:14 +0000 (22:22 -0700)]
i386: work around miscompilation of alternatives code
A recent change makes my Dell 1501 hang on boot. It's an AMD MK-36. I use
an x86_64 kernel. It is 100% reproducible.
I debugged this problem a bit and my compiler[1]interprets the =A constraint
as %rax instead of %edx:%eax on x86_64 which causes the problem. The appended
patch provides a workaround for this and fixed the hang on my machine.
[1] gcc version 4.1.3 20070429 (prerelease) (Debian 4.1.2-5)
J. Bruce Fields [Thu, 10 May 2007 22:38:43 +0000 (18:38 -0400)]
locks: fix F_GETLK regression (failure to find conflicts)
In 9d6a8c5c213e34c475e72b245a8eb709258e968c we changed posix_test_lock
to modify its single file_lock argument instead of taking separate input
and output arguments. This makes it no longer safe to set the output
lock's fl_type to F_UNLCK before looking for a conflict, since that
means searching for a conflict against a lock with type F_UNLCK.
This fixes a regression which causes F_GETLK to incorrectly report no
conflict on most filesystems (including any filesystem that doesn't do
its own locking).
Also fix posix_lock_to_flock() to copy the lock type. This isn't
strictly necessary, since the caller already does this; but it seems
less likely to cause confusion in the future.
* master.kernel.org:/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
[WATCHDOG] MTX-1 Watchdog driver
[WATCHDOG] s3c2410_wdt - initialize watchdog irq resource
[WATCHDOG] Kconfig menuconfig patch
[WATCHDOG] pcwd.c: Port to the new device driver model
[WATCHDOG] use mutex instead of semaphore in Berkshire USB-PC Watchdog driver
[WATCHDOG] the scheduled removal of the i8xx_tco watchdog driver
[WATCHDOG] Semi-typical watchdog bug re early misc_register()
[WATCHDOG] add support for the w83627thf chipset.
Simon Horman [Thu, 10 May 2007 18:51:11 +0000 (11:51 -0700)]
Allow compat_ioctl.c to compile without CONFIG_NET
A small regression appears to have been introduced in the recent patch
"cleanup compat ioctl handling", which was included in Linus' tree after
2.6.20.
siocdevprivate_ioctl() is no longer defined if CONFIG_NET is undefined,
whereas previously it was a dummy function in this case.
This causes compilation with CONFIG_COMPAT but without CONFIG_NET to fail.
fs/compat_ioctl.c: In function `compat_sys_ioctl':
fs/compat_ioctl.c:3571: warning: implicit declaration of function `siocdevprivate_ioctl'
Cc: Christoph Hellwig <hch@lst.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/input/misc/ixp4xx-beeper.c: In function 'ixp4xx_spkr_event':
drivers/input/misc/ixp4xx-beeper.c:54: error: 'input_dev' undeclared (first use in this function)
drivers/input/misc/ixp4xx-beeper.c:54: error: (Each undeclared identifier is reported only once
drivers/input/misc/ixp4xx-beeper.c:54: error: for each function it appears in.)
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Acked-by: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Thu, 10 May 2007 20:32:24 +0000 (13:32 -0700)]
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (24 commits)
[POWERPC] Fix compile error with kexec and CONFIG_SMP=n
[POWERPC] Split initrd logic out of early_init_dt_scan_chosen() to fix warning
[POWERPC] Fix warning in hpte_decode(), and generalize it
[POWERPC] Minor pSeries IOMMU debug cleanup
[POWERPC] PS3: Fix sys manager build error
[POWERPC] Assorted janitorial EEH cleanups
[POWERPC] We don't define CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
[POWERPC] pmu_sys_suspended is only defined for PPC32
[POWERPC] Fix incorrect calculation of I/O window addresses
[POWERPC] celleb: Update celleb_defconfig
[POWERPC] celleb: Fix parsing of machine type hack command line option
[POWERPC] celleb: Fix PCI config space accesses to subordinate buses
[POWERPC] celleb: Fix support for multiple PCI domains
[POWERPC] Wire up sys_utimensat
[POWERPC] CPM_UART: Removed __init from cpm_uart_init_portdesc to fix warning
[POWERPC] User rheap from arch/powerpc/lib
[POWERPC] 83xx: Fix the PCI ranges in the MPC834x_MDS device tree.
[POWERPC] 83xx: Fix the PCI ranges in the MPC832x_MDS device tree.
[POWERPC] CPM_UART: cpm_uart_set_termios should take ktermios, not termios
[POWERPC] Change rheap functions to use ulongs instead of pointers
...
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
[SPARC64]: Use alloc_pci_dev() in PCI bus probes.
[SPARC64]: Bump PROMINTR_MAX to 32.
[SPARC64]: Fix recursion in PROM tree building.
[SERIAL] sunzilog: Interrupt enable before ISR handler installed
[SPARC64] PCI: Consolidate PCI access code into pci_common.c
Linus Torvalds [Thu, 10 May 2007 20:30:34 +0000 (13:30 -0700)]
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
acpi,msi-laptop: Fall back to EC polling mode for MSI laptop specific EC commands
sony-laptop: rename SONY_LAPTOP_OLD to a more meaningful SONYPI_COMPAT
asus-laptop: version bump and lindent
asus-laptop: fix light sens init
asus-laptop: add GPS support
asus-laptop: notify ALL events
ACPICA: Lindent
ACPI: created a dedicated workqueue for notify() execution
Revert "ACPICA: fix AML mutex re-entrancy"
Revert "Execute AML Notify() requests on stack."
Revert "ACPICA: revert "acpi_serialize" changes"
ACPI: delete un-reliable concept of cooling mode
ACPI: thermal trip points are read-only
Linus Torvalds [Thu, 10 May 2007 20:29:36 +0000 (13:29 -0700)]
Merge branch 'juju' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6
* 'juju' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: (138 commits)
firewire: Convert OHCI driver to use standard goto unwinding for error handling.
firewire: Always use parens with sizeof.
firewire: Drop single buffer request support.
firewire: Add a comment to describe why we split the sg list.
firewire: Return SCSI_MLQUEUE_HOST_BUSY for out of memory cases in queuecommand.
firewire: Handle the last few DMA mapping error cases.
firewire: Allocate scsi_host up front and allocate the sbp2_device as hostdata.
firewire: Provide module aliase for backwards compatibility.
firewire: Add to fw-core-y instead of assigning fw-core-objs in Makefile.
firewire: Break out shared IEEE1394 constant to separate header file.
firewire: Use linux/*.h instead of asm/*.h header files.
firewire: Uppercase most macro names.
firewire: Coding style cleanup: no spaces after function names.
firewire: Convert card_rwsem to a regular mutex.
firewire: Clean up comment style.
firewire: Use lib/ implementation of CRC ITU-T.
CRC ITU-T V.41
firewire: Rename fw-device-cdev.c to fw-cdev.c and move header to include/linux.
firewire: Future proof the iso ioctls by adding a handle for the iso context.
firewire: Add read/write and size annotations to IOC numbers.
...
Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Thu, 10 May 2007 18:50:51 +0000 (11:50 -0700)]
Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
[S390] update default configuration.
[S390] Kconfig: no wireless on s390.
[S390] Kconfig: use common Kconfig files for s390.
[S390] Kconfig: common config options for s390.
[S390] Kconfig: unwanted menus for s390.
[S390] Kconfig: menus with depends on HAS_IOMEM.
[S390] Kconfig: refine depends statements.
[S390] Avoid compile warning.
[S390] qdio: re-add lost perf_stats.tl_runs change in qdio_handle_pci
[S390] Avoid sparse warnings.
[S390] dasd: Fix modular build.
[S390] monreader inlining cleanup.
[S390] cio: Make some structures and a function static.
[S390] cio: Get rid of _ccw_device_get_device_number().
[S390] fix subsystem removal fallout
timer: revert parenthesis fix in tbase_get_deferrable() etc
On 09-05-2007 21:10, Pallipadi, Venkatesh wrote:
...
> On a 64 bit system, converting pointer to int causes unnecessary
> compiler warning, and intermediate long conversion was to avoid that.
> I will have to rephrase my comment to remove 32 bit value and use int,
> as that is what the function returns.
So, this patch reverts all changes done by my previous patch.
I apologize for my wrong comment about "logical error" here.
Alexey Dobriyan [Thu, 10 May 2007 10:15:58 +0000 (03:15 -0700)]
i2c-at91: compile fix (IS_ERR)
CC drivers/i2c/busses/i2c-at91.o
drivers/i2c/busses/i2c-at91.c: In function 'at91_i2c_probe':
drivers/i2c/busses/i2c-at91.c:213: warning: implicit declaration of function 'IS_ERR'
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Brownell <david-b@pacbell.net> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Brownell [Thu, 10 May 2007 10:15:52 +0000 (03:15 -0700)]
i2c-at91 supports new-style i2c drivers
Make i2c-at91 register as i2c adapter zero (none of these chips seem to
have more than one TWI controllers) to let it kick in any board-specific
device declarations; also make it hotplug/coldplug.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Jean Delvare <khali@linux-fr.org> Cc: Andrew Victor <andrew@sanpeople.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NeilBrown [Thu, 10 May 2007 10:15:50 +0000 (03:15 -0700)]
md: avoid a possibility that a read error can wrongly propagate through md/raid1 to a filesystem.
When a raid1 has only one working drive, we want read error to propagate up
to the filesystem as there is no point failing the last drive in an array.
Currently the code perform this check is racy. If a write and a read a
both submitted to a device on a 2-drive raid1, and the write fails followed
by the read failing, the read will see that there is only one working drive
and will pass the failure up, even though the one working drive is actually
the *other* one.
So, tighten up the locking.
Signed-off-by: Neil Brown <neilb@suse.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dmitry Torokhov [Thu, 10 May 2007 10:15:47 +0000 (03:15 -0700)]
drivers/hwmon: switch to using input_dev->dev.parent
In preparation for struct class_device -> struct device input core
conversion, switch to using input_dev->dev.parent when specifying device
position in sysfs tree.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Entering the kernel at startup_32 without passing our real mode data in
%esi, and without guaranteeing that physical and virtual addresses are
identity mapped makes head.S impossible to maintain.
The only user of this infrastructure is lguest which is not merged so
nothing we currently support will break by removing this over designed
nightmare, and only the pending lguest patches will be affected. The
pending Xen patches have a different entry point that they use.
We are currently discussing what Xen and lguest need to do to boot the
kernel in a more normal fashion so using startup_32 in this weird manner is
clearly not their long term direction.
So let's remove this code in head.S before it causes brain damage to people
trying to maintain head.S
Cc: Chris Wright <chrisw@sous-sol.org> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Zachary Amsden <zach@vmware.com> CC: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stephen Rothwell [Thu, 10 May 2007 10:15:27 +0000 (03:15 -0700)]
early_pfn_to_nid needs to be __meminit
Since it is referenced by memmap_init_zone (which is __meminit) via the
early_pfn_in_nid macro when CONFIG_NODES_SPAN_OTHER_NODES is set (which
basically means PowerPC 64).
This removes a section mismatch warning in those circumstances.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Howells [Thu, 10 May 2007 10:15:23 +0000 (03:15 -0700)]
AFS: further write support fixes
Further fixes for AFS write support:
(1) The afs_send_pages() outer loop must do an extra iteration if it ends
with 'first == last' because 'last' is inclusive in the page set
otherwise it fails to send the last page and complete the RxRPC op under
some circumstances.
(2) Similarly, the outer loop in afs_pages_written_back() must also do an
extra iteration if it ends with 'first == last', otherwise it fails to
clear PG_writeback on the last page under some circumstances.
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
slub: support concurrent local and remote frees and allocs on a slab
Avoid atomic overhead in slab_alloc and slab_free
SLUB needs to use the slab_lock for the per cpu slabs to synchronize with
potential kfree operations. This patch avoids that need by moving all free
objects onto a lockless_freelist. The regular freelist continues to exist
and will be used to free objects. So while we consume the
lockless_freelist the regular freelist may build up objects.
If we are out of objects on the lockless_freelist then we may check the
regular freelist. If it has objects then we move those over to the
lockless_freelist and do this again. There is a significant savings in
terms of atomic operations that have to be performed.
We can even free directly to the lockless_freelist if we know that we are
running on the same processor. So this speeds up short lived objects.
They may be allocated and freed without taking the slab_lock. This is
particular good for netperf.
In order to maximize the effect of the new faster hotpath we extract the
hottest performance pieces into inlined functions. These are then inlined
into kmem_cache_alloc and kmem_cache_free. So hotpath allocation and
freeing no longer requires a subroutine call within SLUB.
[I am not sure that it is worth doing this because it changes the easy to
read structure of slub just to reduce atomic ops. However, there is
someone out there with a benchmark on 4 way and 8 way processor systems
that seems to show a 5% regression vs. Slab. Seems that the regression is
due to increased atomic operations use vs. SLAB in SLUB). I wonder if
this is applicable or discernable at all in a real workload?]
Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Olaf Hering [Sat, 5 May 2007 21:17:13 +0000 (23:17 +0200)]
firewire: Provide module aliase for backwards compatibility.
This patch loads fw-sbp2 if sbp2 is still in the config file. So one can
go back and forth between releases without worry about the root
filesystem drivers.
Signed-off-by: Kristian Hoegsberg <krh@redhat.com>
Existing mkinitrd scripts still have to be adapted, unless they grok
module aliases.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
projects / linux-2.6 / log