Correct the return type of handle_IRQ_event() (inconsistency noticed during
Xen development), and remove redundant declarations. The return type
adjustment required breaking out the definition of irqreturn_t into a
separate header, in order to satisfy current include order dependencies.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This uninlines a few large functions in uaccess.h and cleans up the rest.
It includes a (hopefully temporary) workaround for the broken typeof of
gcc-4.1.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove long obsolete kernel syscalls, only execve is still used.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
These include nothing more than the basic set of files listed in
asm-generic/Kbuild.asm. Any extra arch-specific files will need to be
added.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
These aren't needed by glibc or klibc, and they're broken in some cases
anyway. The uClibc folks are apparently switching over to stop using
them too (now that we agreed that they should be dropped, at least).
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Bitmap functions for the minix filesystem and the ext2 filesystem except
ext2_set_bit_atomic() and ext2_clear_bit_atomic() do not require the atomic
guarantees.
But these are defined by using atomic bit operations on several architectures.
(cris, frv, h8300, ia64, m32r, m68k, m68knommu, mips, s390, sh, sh64, sparc,
sparc64, v850, and xtensa)
This patch switches to non atomic bit operation.
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch series fixes the following problems on 32 bits architecture.
o stat64 returns the lower 32 bits of blocks, although userland st_blocks
has 64 bits, because i_blocks has only 32 bits. The ioctl with FIOQSIZE has
the same problem.
o As Dave Kleikamp said, making >2TB file on JFS results in writing an
invalid block number to disk inode. The cause is the same as above too.
o In generic quota code dquot_transfer(), the file usage is calculated from
i_blocks via inode_get_bytes(). If the file is over 2TB, the change of
usage is less than expected. The cause is the same as above too.
o As Trond Myklebust said, statfs64's entries related to blocks are invalid
on statfs64 for a network filesystem which has more than 2^32-1 blocks with
CONFIG_LBD disabled. [PATCH 3/3]
We made patches to fix problems that occur when handling a large filesystem
and a large file. It was discussed on the mails titled "stat64 for over 2TB
file returned invalid st_blocks".
Signed-off-by: Takashi Sato <sho@tnes.nec.co.jp>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Implement the half-closed devices notifiation, by adding a new POLLRDHUP
(and its alias EPOLLRDHUP) bit to the existing poll/select sets. Since the
existing POLLHUP handling, that does not report correctly half-closed
devices, was feared to be changed, this implementation leaves the current
POLLHUP reporting unchanged and simply add a new bit that is set in the few
places where it makes sense. The same thing was discussed and conceptually
agreed quite some time ago:
http://lkml.org/lkml/2003/7/12/116
Since this new event bit is added to the existing Linux poll infrastruture,
even the existing poll/select system calls will be able to use it. As far
as the existing POLLHUP handling, the patch leaves it as is. The
pollrdhup-2.6.16.rc5-0.10.diff defines the POLLRDHUP for all the existing
archs and sets the bit in the six relevant files. The other attached diff
is the simple change required to sys/epoll.h to add the EPOLLRDHUP
definition.
There is "a stupid program" to test POLLRDHUP delivery here:
http://www.xmailserver.org/pollrdhup-test.c
It tests poll(2), but since the delivery is same epoll(2) will work equally.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Without branch hints, the very unlikely chance of the loop repeating due to
cmpxchg failure is unrolled with gcc-4 that I have tested.
Improve this for architectures with a native cas/cmpxchg. llsc archs
should try to implement this natively.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We require that all archs implement atomic_cmpxchg(), for the generic
version of atomic_add_unless().
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch claiming to remove enable_irq_nosync() had left it alive but killed
disable_irq_nosync() instead...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Make new MADV_REMOVE, MADV_DONTFORK, MADV_DOFORK consistent across all
arches. The idea is to make it possible to use them portably even before
distros include them in libc headers.
Move common flags to asm-generic/mman.h
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently, copy-on-write may change the physical address of a page even if the
user requested that the page is pinned in memory (either by mlock or by
get_user_pages). This happens if the process forks meanwhile, and the parent
writes to that page. As a result, the page is orphaned: in case of
get_user_pages, the application will never see any data hardware DMA's into
this page after the COW. In case of mlock'd memory, the parent is not getting
the realtime/security benefits of mlock.
In particular, this affects the Infiniband modules which do DMA from and into
user pages all the time.
This patch adds madvise options to control whether memory range is inherited
across fork. Useful e.g. for when hardware is doing DMA from/into these
pages. Could also be useful to an application wanting to speed up its forks
by cutting large areas out of consideration.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
function arguments can't be inline, TYVM...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
extern declaration of static object removed from header
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
extern declaration of static object removed from header
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
in amigahw.h custom renamed to amiga_custom, in drivers with few instances the
same replacement, in the rest - #define custom amiga_custom in driver itself
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
move the sanity check for NR_IRQS being no more than 1<<HARDIRQ_BITS from
asm-m68k/hardirq.h to asm-m68k/irq.h; needed since NR_IRQS is not necessary
know at the points of inclusion of asm/hardirq.h due to the rather ugly header
dependencies on m68k. Fix is by far simpler than trying to massage those
dependencies...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patchset annotates arch/* uses of ->thread_info. Ones that really are about
access of thread_info of given process are simply switched to
task_thread_info(task); ones that deal with access to objects on stack are
switched to new helper - task_stack_page(). A _lot_ of the latter are
actually open-coded instances of "find where pt_regs are"; those are
consolidated into task_pt_regs(task) (many architectures actually have such
helper already).
Note that these annotations are not mandatory - any code not converted to
these helpers still works. However, they clean up a lot of places and have
actually caught a number of bugs, so converting out of tree ports would be a
good idea...
As an example of breakage caught by that stuff, see i386 pt_regs mess - we
used to have it open-coded in a bunch of places and when back in April Stas
had fixed a bug in copy_thread(), the rest had been left out of sync. That
required two followup patches (the latest - just before 2.6.15) _and_ still
had left /proc/*/stat eip field broken. Try ps -eo eip on i386 and watch the
junk...
This patch:
new helper - task_stack_page(task). Returns pointer to the memory object
containing task stack; usually thread_info of task sits in the beginning
of that object.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Most arches copied the i386 ioctl.h. Combine them into a generic header.
Signed-off-by: Brian Gerst <bgerst@didntduck.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
add the per-arch mutex.h files for the remaining architectures.
We default to asm-generic/mutex-dec.h, because that performs
quite well on most arches. Arches that do not have atomic
decrement/increment instructions should switch to mutex-xchg.h
instead. Arches can also provide their own implementation for
the mutex fastpath primitives.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add atomic_xchg() to all the architectures. Needed by the new mutex code.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Most of the architectures have the same asm/futex.h. This consolidates them
into asm-generic, with the arches including it from their own asm/futex.h.
In the case of UML, this reverts the old broken futex.h and goes back to using
the same one as almost everyone else.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Kill L1_CACHE_SHIFT from all arches. Since L1_CACHE_SHIFT_MAX is not used
anymore with the introduction of INTERNODE_CACHE, kill L1_CACHE_SHIFT_MAX.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
m68k, m68knommu and h8300 define this, but it's not actually used
anywhere.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Several counters already have the need to use 64 atomic variables on 64 bit
platforms (see mm_counter_t in sched.h). We have to do ugly ifdefs to fall
back to 32 bit atomic on 32 bit platforms.
The VM statistics patch that I am working on will also make more extensive
use of atomic64.
This patch introduces a new type atomic_long_t by providing definitions in
asm-generic/atomic.h that works similar to the c "long" type. Its 32 bits
on 32 bit platforms and 64 bits on 64 bit platforms.
Also cleans up the determination of the mm_counter_t in sched.h.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here is the patch to implement madvise(MADV_REMOVE) - which frees up a
given range of pages & its associated backing store. Current
implementation supports only shmfs/tmpfs and other filesystems return
-ENOSYS.
"Some app allocates large tmpfs files, then when some task quits and some
client disconnect, some memory can be released. However the only way to
release tmpfs-swap is to MADV_REMOVE". - Andrea Arcangeli
Databases want to use this feature to drop a section of their bufferpool
(shared memory segments) - without writing back to disk/swap space.
This feature is also useful for supporting hot-plug memory on UML.
Concerns raised by Andrew Morton:
- "We have no plan for holepunching! If we _do_ have such a plan (or
might in the future) then what would the API look like? I think
sys_holepunch(fd, start, len), so we should start out with that."
- Using madvise is very weird, because people will ask "why do I need to
mmap my file before I can stick a hole in it?"
- None of the other madvise operations call into the filesystem in this
manner. A broad question is: is this capability an MM operation or a
filesytem operation? truncate, for example, is a filesystem operation
which sometimes has MM side-effects. madvise is an mm operation and with
this patch, it gains FS side-effects, only they're really, really
significant ones."
Comments:
- Andrea suggested the fs operation too but then it's more efficient to
have it as a mm operation with fs side effects, because they don't
immediatly know fd and physical offset of the range. It's possible to
fixup in userland and to use the fs operation but it's more expensive,
the vmas are already in the kernel and we can use them.
Short term plan & Future Direction:
- We seem to need this interface only for shmfs/tmpfs files in the short
term. We have to add hooks into the filesystem for correctness and
completeness. This is what this patch does.
- In the future, plan is to support both fs and mmap apis also. This
also involves (other) filesystem specific functions to be implemented.
- Current patch doesn't support VM_NONLINEAR - which can be addressed in
the future.
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Andrea Arcangeli <andrea@suse.de>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce an atomic_inc_not_zero operation. Make this a special case of
atomic_add_unless because lockless pagecache actually wants
atomic_inc_not_negativeone due to its offset refcount.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove task_work structure, use the standard thread flags functions and use
shifts in entry.S to test the thread flags. Add a few local labels to entry.S
to allow gas to generate short jumps.
Finally it changes a number of inline functions in thread_info.h to macros to
delay the current_thread_info() usage, which requires on m68k a structure
(task_struct) not yet defined at this point.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
a) added embedded thread_info [m68k processor.h]
b) added missing symbols in asm-offsets.c
c) task_thread_info() and friends in asm-m68k/thread_info.h
d) made m68k thread_info.h included by m68k processor.h, not the other way
round.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Would you mind applying the following patch that kills those two + the
m68k and Documentation/ references?
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
I don't know if we ever implemented this, but the only user in any 2.6
tree are the compat ioctls.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
__MUTEX_INITIALIZER() has no users, and equates to the more commonly used
DECLARE_MUTEX(), thus making it pretty much redundant. Remove it for good.
Signed-off-by: Arthur Othieno <a.othieno@bluewin.ch>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make sure we always return, as all syscalls should. Also move the common
prototype to <linux/syscalls.h>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Removed some more references to check_region().
I checked these changes into the 'checkreg' branch of
rsync://rsync.kernel.org/pub/scm/linux/kernel/git/jgarzik/misc-2.6.git
The only valid references remaining are in:
drivers/scsi/advansys.c
drivers/scsi/BusLogic.c
drivers/cdrom/sbpcd.c
sound/oss/pss.c
Remove last vestiges of ide_check_region()
drivers/char/specialix: trim trailing whitespace
drivers/char/specialix: eliminate use of check_region()
Remove outdated and unused references to check_region()
[sound oss] remove check_region() usage from cs4232, wavfront
[netdrvr eepro] trim trailing whitespace
[netdrvr eepro] remove check_region() usage
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As recently done by Russell King for ARM, commit
4732efbeb9 introduces a generic asm/futex.h copied
along most arches, which includes a "-ENOSYS support" to be changed if needed.
However, it includes an unused var (taken from the "real" version) which GCC
warns about.
Remove it from all arches having that file version (i.e. same GIT id).
$ git-diff-tree -r HEAD
and
$ git-ls-tree -r HEAD include/|grep 9feff4ce14
may be more interesting than looking at the patch itself, to make sure I've
just copied the arm header to all other archs having the original dummy version
of this file.
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As written in Documentation/feature-removal-schedule.txt, remove the
io_remap_page_range() kernel API.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch gathers all the struct flock64 definitions (and the operations),
puts them under !CONFIG_64BIT and cleans up the arch files.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch just gathers together all the struct flock definitions except
xtensa into asm-generic/fcntl.h.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch puts the most popular of each fcntl operation/flag into
asm-generic/fcntl.h and cleans up the arch files.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch puts the most popular of each open flag into asm-generic/fcntl.h
and cleans up the arch files.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This set of patches creates asm-generic/fcntl.h and consolidates as much as
possible from the asm-*/fcntl.h files into it.
This patch just gathers all the identical bits of the asm-*/fcntl.h files into
asm-generic/fcntl.h.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
unused and useless..
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The size of auxiliary vector is fixed at 42 in linux/sched.h. But it isn't
very obvious when looking at linux/elf.h. This patch adds AT_VECTOR_SIZE
so that we can change it if necessary when a new vector is added.
Because of include file ordering problems, doing this necessitated the
extraction of the AT_* symbols into a standalone header file.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ATM pthread_cond_signal is unnecessarily slow, because it wakes one waiter
(which at least on UP usually means an immediate context switch to one of
the waiter threads). This waiter wakes up and after a few instructions it
attempts to acquire the cv internal lock, but that lock is still held by
the thread calling pthread_cond_signal. So it goes to sleep and eventually
the signalling thread is scheduled in, unlocks the internal lock and wakes
the waiter again.
Now, before 2003-09-21 NPTL was using FUTEX_REQUEUE in pthread_cond_signal
to avoid this performance issue, but it was removed when locks were
redesigned to the 3 state scheme (unlocked, locked uncontended, locked
contended).
Following scenario shows why simply using FUTEX_REQUEUE in
pthread_cond_signal together with using lll_mutex_unlock_force in place of
lll_mutex_unlock is not enough and probably why it has been disabled at
that time:
The number is value in cv->__data.__lock.
thr1 thr2 thr3
0 pthread_cond_wait
1 lll_mutex_lock (cv->__data.__lock)
0 lll_mutex_unlock (cv->__data.__lock)
0 lll_futex_wait (&cv->__data.__futex, futexval)
0 pthread_cond_signal
1 lll_mutex_lock (cv->__data.__lock)
1 pthread_cond_signal
2 lll_mutex_lock (cv->__data.__lock)
2 lll_futex_wait (&cv->__data.__lock, 2)
2 lll_futex_requeue (&cv->__data.__futex, 0, 1, &cv->__data.__lock)
# FUTEX_REQUEUE, not FUTEX_CMP_REQUEUE
2 lll_mutex_unlock_force (cv->__data.__lock)
0 cv->__data.__lock = 0
0 lll_futex_wake (&cv->__data.__lock, 1)
1 lll_mutex_lock (cv->__data.__lock)
0 lll_mutex_unlock (cv->__data.__lock)
# Here, lll_mutex_unlock doesn't know there are threads waiting
# on the internal cv's lock
Now, I believe it is possible to use FUTEX_REQUEUE in pthread_cond_signal,
but it will cost us not one, but 2 extra syscalls and, what's worse, one of
these extra syscalls will be done for every single waiting loop in
pthread_cond_*wait.
We would need to use lll_mutex_unlock_force in pthread_cond_signal after
requeue and lll_mutex_cond_lock in pthread_cond_*wait after lll_futex_wait.
Another alternative is to do the unlocking pthread_cond_signal needs to do
(the lock can't be unlocked before lll_futex_wake, as that is racy) in the
kernel.
I have implemented both variants, futex-requeue-glibc.patch is the first
one and futex-wake_op{,-glibc}.patch is the unlocking inside of the kernel.
The kernel interface allows userland to specify how exactly an unlocking
operation should look like (some atomic arithmetic operation with optional
constant argument and comparison of the previous futex value with another
constant).
It has been implemented just for ppc*, x86_64 and i?86, for other
architectures I'm including just a stub header which can be used as a
starting point by maintainers to write support for their arches and ATM
will just return -ENOSYS for FUTEX_WAKE_OP. The requeue patch has been
(lightly) tested just on x86_64, the wake_op patch on ppc64 kernel running
32-bit and 64-bit NPTL and x86_64 kernel running 32-bit and 64-bit NPTL.
With the following benchmark on UP x86-64 I get:
for i in nptl-orig nptl-requeue nptl-wake_op; do echo time elf/ld.so --library-path .:$i /tmp/bench; \
for j in 1 2; do echo ( time elf/ld.so --library-path .:$i /tmp/bench ) 2>&1; done; done
time elf/ld.so --library-path .:nptl-orig /tmp/bench
real 0m0.655s user 0m0.253s sys 0m0.403s
real 0m0.657s user 0m0.269s sys 0m0.388s
time elf/ld.so --library-path .:nptl-requeue /tmp/bench
real 0m0.496s user 0m0.225s sys 0m0.271s
real 0m0.531s user 0m0.242s sys 0m0.288s
time elf/ld.so --library-path .:nptl-wake_op /tmp/bench
real 0m0.380s user 0m0.176s sys 0m0.204s
real 0m0.382s user 0m0.175s sys 0m0.207s
The benchmark is at:
http://sourceware.org/ml/libc-alpha/2005-03/txt00001.txt
Older futex-requeue-glibc.patch version is at:
http://sourceware.org/ml/libc-alpha/2005-03/txt00002.txt
Older futex-wake_op-glibc.patch version is at:
http://sourceware.org/ml/libc-alpha/2005-03/txt00003.txt
Will post a new version (just x86-64 fixes so that the patch
applies against pthread_cond_signal.S) to libc-hacker ml soon.
Attached is the kernel FUTEX_WAKE_OP patch as well as a simple-minded
testcase that will not test the atomicity of the operation, but at least
check if the threads that should have been woken up are woken up and
whether the arithmetic operation in the kernel gave the expected results.
Acked-by: Ingo Molnar <mingo@redhat.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Jamie Lokier <jamie@shareable.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the builtin functions for memset/memclr/memcpy, special optimizations for
page operations have dedicated functions now. Uninline memmove/memchr and
move all functions into a single file and clean it up a little.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Move a few cache functions into its own file and fix flush_icache_range() so
it can handle both kernel and user addresses correctly (assuming context is
set correctly).
Turn copy_to_user_page/copy_from_user_page into inline functions and add a
missing cache flush.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is used only in slab.c and each architecture gets to define whcih
underlying type is to be used.
Seems a bit silly - move it to slab.c and use the same type for all
architectures: unsigned int.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Someone mentioned that almost all the architectures used basically the same
implementation of get_order. This patch consolidates them into
asm-generic/page.h and includes that in the appropriate places. The
exceptions are ia64 and ppc which have their own (presumably optimised)
versions.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When the kernel is working well and we want to restart cleanly
kernel_restart is the function to use. But in many instances
the kernel wants to reboot when thing are expected to be working
very badly such as from panic or a software watchdog handler.
This patch adds the function emergency_restart() so that
callers can be clear what semantics they expect when calling
restart. emergency_restart() is expected to be callable
from interrupt context and possibly reliable in even more
trying circumstances.
This is an initial generic implementation for all architectures.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
http://bugme.osdl.org/show_bug.cgi?id=4016
Written-by: David Shaohua Li <shaohua.li@intel.com>
Acked-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Remove legacy ISA serial ports for Accent, Boca, Fourport, Hub6 and MCA
from the architecture specific serial.h include.
The only ports which remain in asm-*/serial.h are the platform specific
entries. These should really be converted by platform maintainers to
use a platform device, such as can be found in
arch/arm/mach-footbridge/isa.c
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The preempt_count member of struct thread_info is currently either defined
as int, unsigned int or __s32 depending on arch. This patch makes the type
of preempt_count an int on all archs.
Having preempt_count be an unsigned type prevents the catching of
preempt_count < 0 bugs, and using int on some archs and __s32 on others is
not exactely "neat" - much nicer when it's just int all over.
A previous version of this patch was already ACK'ed by Robert Love, and the
only change in this version of the patch compared to the one he ACK'ed is
that this one also makes sure the preempt_count member is consistently
commented.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
New file - asm-generic/signal.h. Contains declarations of
__sighandler_t, __sigrestore_t, SIG_DFL, SIG_IGN, SIG_ERR and default
definitions of SIG_BLOCK, SIG_UNBLOCK and SIG_SETMASK.
asm-*/signal.h switched to including it. The only exception is
asm-parisc/signal.h that wants its own declaration of __sighandler_t;
that one is left as-is.
asm-ppc64/signal.h required one more thing - unlike everybody else it
used __sigrestorer_t instead of usual __sigrestore_t. PPC64 switched to
common spelling.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The attached patch moves the IRQ-related SA_xxx flags (namely, SA_PROBE,
SA_SAMPLE_RANDOM and SA_SHIRQ) from all the arch-specific headers to
linux/signal.h. This looks like a left-over after the irq-handling code
was consolidated. The code was moved to kernel/irq/*, but the flags are
still left per-arch.
Right now, adding a new IRQ flag to the arch-specific header, like this
patch does:
http://cvs.sourceforge.net/viewcvs.py/*checkout*/alsa/alsa-driver/utils/patches/pcsp-kernel-2.6.10-03.diff?rev=1.1
no longer works, it breaks the compilation for all other arches, unless you
add that flag to all the other arch-specific headers too. So I think such
a clean-up makes sense.
Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch eliminates all kernel BUGs, trims about 35k off the typical
kernel, and makes the system slightly faster.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Replace misleading definition of FIRST_USER_PGD_NR 0 by definition of
FIRST_USER_ADDRESS 0 in all the MMU architectures beyond arm and arm26.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
make defconfig give the following error on ppc (gcc-4):
include/asm-m68k/setup.h:365: error: array type has incomplete element
type
Signed-Off-By: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
