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2006-03-09[PATCH] m68k: fix cmpxchg compile errors if CONFIG_RMW_INSNS=nRoman Zippel
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>
2006-02-18[PATCH] iomap_copy fallout (m68k)Al Viro
added __raw_writel(), sanitized include order in iomap_copy.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-02-18[PATCH] m68k: restore disable_irq_nosync()Al Viro
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>
2006-02-15[PATCH] add asm-generic/mman.hMichael S. Tsirkin
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>
2006-02-14[PATCH] madvise MADV_DONTFORK/MADV_DOFORKMichael S. Tsirkin
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>
2006-01-12[PATCH] m68k: kill mach_floppy_setup, convert to proper __setup() in driversAl Viro
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>
2006-01-12[PATCH] m68k: cast in strnlen switched to unsigned longAl Viro
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>
2006-01-12[PATCH] m68k: NULL noise removalAl Viro
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>
2006-01-12[PATCH] m68k: dsp56k __user annotationsAl Viro
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>
2006-01-12[PATCH] m68k: checksum __user annotationsAl Viro
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>
2006-01-12[PATCH] m68k: signal __user annotationsAl Viro
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>
2006-01-12[PATCH] m68k: basic __user annotationsAl Viro
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>
2006-01-12[PATCH] m68k: basic iomem annotationsAl Viro
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>
2006-01-12[PATCH] m68k: bogus function argument types (sun3_pgtable.h)Al Viro
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>
2006-01-12[PATCH] m68k: static vs. extern in amigaints.hAl Viro
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>
2006-01-12[PATCH] m68k: static vs. extern in sun3ints.hAl Viro
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>
2006-01-12[PATCH] m68k: namespace pollution fix (custom->amiga_custom)Al Viro
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>
2006-01-12[PATCH] m68k: compile fix - hardirq checks were in wrong placeAl Viro
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>
2006-01-12[PATCH] missing helper - task_stack_page()Al Viro
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>
2006-01-10[PATCH] Generic ioctl.hBrian Gerst
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>
2006-01-09[PATCH] mutex subsystem, add default include/asm-*/mutex.h filesArjan van de Ven
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>
2006-01-09[PATCH] mutex subsystem, add atomic_xchg() to all archesIngo Molnar
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>
2006-01-08[PATCH] consolidate asm/futex.hJeff Dike
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>
2006-01-08[PATCH] Kill L1_CACHE_SHIFT_MAXRavikiran G Thirumalai
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>
2006-01-06[PATCH] m68knommu: remove enable_irq_nosync()Christoph Hellwig
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>
2006-01-06[PATCH] atomic_long_t & include/asm-generic/atomic.h V2Christoph Lameter
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>
2006-01-06[PATCH] madvise(MADV_REMOVE): remove pages from tmpfs shm backing storeBadari Pulavarty
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>
2006-01-03[FLS64]: generic versionStephen Hemminger
Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-13[PATCH] atomic: inc_not_zeroNick Piggin
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>
2005-11-13[PATCH] atomic: cmpxchgNick Piggin
Introduce an atomic_cmpxchg operation. 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>
2005-11-13[PATCH] m68k: convert thread flags to use bit fieldsRoman Zippel
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>
2005-11-13[PATCH] m68k: m68k-specific thread_info changesAl Viro
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>
2005-11-07[SPARC]: Kill remaining kbio.h references.Christoph Hellwig
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>
2005-11-07[SPARC]: remove vuid_event.hChristoph Hellwig
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>
2005-10-30[PATCH] semaphore: Remove __MUTEX_INITIALIZER()Arthur Othieno
__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>
2005-10-30[PATCH] unify sys_ptrace prototypeChristoph Hellwig
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>
2005-10-30[PATCH] remove some more check_region stuffJeff Garzik
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>
2005-09-21[PATCH] Remove unused var from asm/futex.hPaolo 'Blaisorblade' Giarrusso
As recently done by Russell King for ARM, commit 4732efbeb997189d9f9b04708dc26bf8613ed721 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 9feff4ce1424bc390608326240be369eb13aa648 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>
2005-09-13[PATCH] feature removal of io_remap_page_range()Randy Dunlap
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>
2005-09-07[PATCH] Clean up struct flock64 definitionsStephen Rothwell
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>
2005-09-07[PATCH] Clean up struct flock definitionsStephen Rothwell
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>
2005-09-07[PATCH] Clean up the fcntl operationsStephen Rothwell
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>
2005-09-07[PATCH] Clean up the open flagsStephen Rothwell
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>
2005-09-07[PATCH] Create asm-generic/fcntl.hStephen Rothwell
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>
2005-09-07[PATCH] remove verify_area(): remove verify_area() from various uaccess.h ↵Jesper Juhl
headers Remove the deprecated (and unused) verify_area() from various uaccess.h headers. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] remove asm-*/hdreg.hChristoph Hellwig
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>
2005-09-07[PATCH] auxiliary vector cleanupsH. J. Lu
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>
2005-09-07[PATCH] FUTEX_WAKE_OP: pthread_cond_signal() speedupJakub Jelinek
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>
2005-09-05[PATCH] m68k: cleanup inline mem functionsRoman Zippel
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>
2005-09-05[PATCH] m68k: move cache functions into separate fileRoman Zippel
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>