14 Aug, 2012
1 commit
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ARM recently moved to asm-generic/mutex-xchg.h for its mutex
implementation after the previous implementation was found to be missing
some crucial memory barriers. However, this has revealed some problems
running hackbench on SMP platforms due to the way in which the
MUTEX_SPIN_ON_OWNER code operates.The symptoms are that a bunch of hackbench tasks are left waiting on an
unlocked mutex and therefore never get woken up to claim it. This boils
down to the following sequence of events:Task A Task B Task C Lock value
0 1
1 lock() 0
2 lock() 0
3 spin(A) 0
4 unlock() 1
5 lock() 0
6 cmpxchg(1,0) 0
7 contended() -1
8 lock() 0
9 spin(C) 0
10 unlock() 1
11 cmpxchg(1,0) 0
12 unlock() 1At this point, the lock is unlocked, but Task B is in an uninterruptible
sleep with nobody to wake it up.This patch fixes the problem by ensuring we put the lock into the
contended state if we fail to acquire it on the fastpath, ensuring that
any blocked waiters are woken up when the mutex is released.Signed-off-by: Will Deacon
Cc: Arnd Bergmann
Cc: Chris Mason
Cc: Ingo Molnar
Cc:
Reviewed-by: Nicolas Pitre
Signed-off-by: Peter Zijlstra
Link: http://lkml.kernel.org/n/tip-6e9lrw2avczr0617fzl5vqb8@git.kernel.org
Signed-off-by: Thomas Gleixner
31 Jul, 2012
3 commits
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Merge Andrew's first set of patches:
"Non-MM patches:- lots of misc bits
- tree-wide have_clk() cleanups
- quite a lot of printk tweaks. I draw your attention to "printk:
convert the format for KERN_ to a 2 byte pattern" which
looks a bit scary. But afaict it's solid.- backlight updates
- lib/ feature work (notably the addition and use of memweight())
- checkpatch updates
- rtc updates
- nilfs updates
- fatfs updates (partial, still waiting for acks)
- kdump, proc, fork, IPC, sysctl, taskstats, pps, etc
- new fault-injection feature work"
* Merge emailed patches from Andrew Morton : (128 commits)
drivers/misc/lkdtm.c: fix missing allocation failure check
lib/scatterlist: do not re-write gfp_flags in __sg_alloc_table()
fault-injection: add tool to run command with failslab or fail_page_alloc
fault-injection: add selftests for cpu and memory hotplug
powerpc: pSeries reconfig notifier error injection module
memory: memory notifier error injection module
PM: PM notifier error injection module
cpu: rewrite cpu-notifier-error-inject module
fault-injection: notifier error injection
c/r: fcntl: add F_GETOWNER_UIDS option
resource: make sure requested range is included in the root range
include/linux/aio.h: cpp->C conversions
fs: cachefiles: add support for large files in filesystem caching
pps: return PTR_ERR on error in device_create
taskstats: check nla_reserve() return
sysctl: suppress kmemleak messages
ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION
ipc: compat: use signed size_t types for msgsnd and msgrcv
ipc: allow compat IPC version field parsing if !ARCH_WANT_OLD_COMPAT_IPC
ipc: add COMPAT_SHMLBA support
... -
When we restore file descriptors we would like them to look exactly as
they were at dumping time.With help of fcntl it's almost possible, the missing snippet is file
owners UIDs.To be able to read their values the F_GETOWNER_UIDS is introduced.
This option is valid iif CONFIG_CHECKPOINT_RESTORE is turned on, otherwise
returning -EINVAL.Signed-off-by: Cyrill Gorcunov
Acked-by: "Eric W. Biederman"
Cc: "Serge E. Hallyn"
Cc: Oleg Nesterov
Cc: Pavel Emelyanov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Pull DMA-mapping updates from Marek Szyprowski:
"Those patches are continuation of my earlier work.They contains extensions to DMA-mapping framework to remove limitation
of the current ARM implementation (like limited total size of DMA
coherent/write combine buffers), improve performance of buffer sharing
between devices (attributes to skip cpu cache operations or creation
of additional kernel mapping for some specific use cases) as well as
some unification of the common code for dma_mmap_attrs() and
dma_mmap_coherent() functions. All extensions have been implemented
and tested for ARM architecture."* 'for-linus-for-3.6-rc1' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
ARM: dma-mapping: add support for DMA_ATTR_SKIP_CPU_SYNC attribute
common: DMA-mapping: add DMA_ATTR_SKIP_CPU_SYNC attribute
ARM: dma-mapping: add support for dma_get_sgtable()
common: dma-mapping: introduce dma_get_sgtable() function
ARM: dma-mapping: add support for DMA_ATTR_NO_KERNEL_MAPPING attribute
common: DMA-mapping: add DMA_ATTR_NO_KERNEL_MAPPING attribute
common: dma-mapping: add support for generic dma_mmap_* calls
ARM: dma-mapping: fix error path for memory allocation failure
ARM: dma-mapping: add more sanity checks in arm_dma_mmap()
ARM: dma-mapping: remove custom consistent dma region
mm: vmalloc: use const void * for caller argument
scatterlist: add sg_alloc_table_from_pages function
30 Jul, 2012
2 commits
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This patch adds dma_get_sgtable() function which is required to let
drivers to share the buffers allocated by DMA-mapping subsystem. Right
now the driver gets a dma address of the allocated buffer and the kernel
virtual mapping for it. If it wants to share it with other device (= map
into its dma address space) it usually hacks around kernel virtual
addresses to get pointers to pages or assumes that both devices share
the DMA address space. Both solutions are just hacks for the special
cases, which should be avoided in the final version of buffer sharing.To solve this issue in a generic way, a new call to DMA mapping has been
introduced - dma_get_sgtable(). It allocates a scatter-list which
describes the allocated buffer and lets the driver(s) to use it with
other device(s) by calling dma_map_sg() on it.This patch provides a generic implementation based on virt_to_page()
call. Architectures which require more sophisticated translation might
provide their own get_sgtable() methods.Signed-off-by: Marek Szyprowski
Reviewed-by: Kyungmin Park
Reviewed-by: Daniel Vetter -
Commit 9adc5374 ('common: dma-mapping: introduce mmap method') added a
generic method for implementing mmap user call to dma_map_ops structure.This patch converts ARM and PowerPC architectures (the only providers of
dma_mmap_coherent/dma_mmap_writecombine calls) to use this generic
dma_map_ops based call and adds a generic cross architecture
definition for dma_mmap_attrs, dma_mmap_coherent, dma_mmap_writecombine
functions.The generic mmap virt_to_page-based fallback implementation is provided for
architectures which don't provide their own implementation for mmap method.Signed-off-by: Marek Szyprowski
Reviewed-by: Kyungmin Park
28 Jul, 2012
3 commits
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Pull ARM updates from Russell King:
"First ARM push of this merge window, post me coming back from holiday.
This is what has been in linux-next for the last few weeks. Not much
to say which isn't described by the commit summaries."* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (32 commits)
ARM: 7463/1: topology: Update cpu_power according to DT information
ARM: 7462/1: topology: factorize the update of sibling masks
ARM: 7461/1: topology: Add arch_scale_freq_power function
ARM: 7456/1: ptrace: provide separate functions for tracing syscall {entry,exit}
ARM: 7455/1: audit: move syscall auditing until after ptrace SIGTRAP handling
ARM: 7454/1: entry: don't bother with syscall tracing on ret_from_fork path
ARM: 7453/1: audit: only allow syscall auditing for pure EABI userspace
ARM: 7452/1: delay: allow timer-based delay implementation to be selected
ARM: 7451/1: arch timer: implement read_current_timer and get_cycles
ARM: 7450/1: dcache: select DCACHE_WORD_ACCESS for little-endian ARMv6+ CPUs
ARM: 7449/1: use generic strnlen_user and strncpy_from_user functions
ARM: 7448/1: perf: remove arm_perf_pmu_ids global enumeration
ARM: 7447/1: rwlocks: remove unused branch labels from trylock routines
ARM: 7446/1: spinlock: use ticket algorithm for ARMv6+ locking implementation
ARM: 7445/1: mm: update CONTEXTIDR register to contain PID of current process
ARM: 7444/1: kernel: add arch-timer C3STOP feature
ARM: 7460/1: remove asm/locks.h
ARM: 7439/1: head.S: simplify initial page table mapping
ARM: 7437/1: zImage: Allow DTB command line concatenation with ATAG_CMDLINE
ARM: 7436/1: Do not map the vectors page as write-through on UP systems
... -
Pull final kmap_atomic cleanups from Cong Wang:
"This should be the final round of cleanup, as the definitions of enum
km_type finally get removed from the whole tree. The patches have
been in linux-next for a long time."* 'kmap_atomic' of git://github.com/congwang/linux:
pipe: remove KM_USER0 from comments
vmalloc: remove KM_USER0 from comments
feature-removal-schedule.txt: remove kmap_atomic(page, km_type)
tile: remove km_type definitions
um: remove km_type definitions
asm-generic: remove km_type definitions
avr32: remove km_type definitions
frv: remove km_type definitions
powerpc: remove km_type definitions
arm: remove km_type definitions
highmem: remove the deprecated form of kmap_atomic
tile: remove usage of enum km_type
frv: remove the second parameter of kmap_atomic_primary()
jbd2: remove the second argument of kmap_atomic
27 Jul, 2012
1 commit
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Pull x86/mm changes from Peter Anvin:
"The big change here is the patchset by Alex Shi to use INVLPG to flush
only the affected pages when we only need to flush a small page range.It also removes the special INVALIDATE_TLB_VECTOR interrupts (32
vectors!) and replace it with an ordinary IPI function call."Fix up trivial conflicts in arch/x86/include/asm/apic.h (added code next
to changed line)* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tlb: Fix build warning and crash when building for !SMP
x86/tlb: do flush_tlb_kernel_range by 'invlpg'
x86/tlb: replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR
x86/tlb: enable tlb flush range support for x86
mm/mmu_gather: enable tlb flush range in generic mmu_gather
x86/tlb: add tlb_flushall_shift knob into debugfs
x86/tlb: add tlb_flushall_shift for specific CPU
x86/tlb: fall back to flush all when meet a THP large page
x86/flush_tlb: try flush_tlb_single one by one in flush_tlb_range
x86/tlb_info: get last level TLB entry number of CPU
x86: Add read_mostly declaration/definition to variables from smp.h
x86: Define early read-mostly per-cpu macros
24 Jul, 2012
1 commit
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Signed-off-by: Cong Wang
06 Jul, 2012
1 commit
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dev_set_cma_area incorrectly assigned cma to global area on first call
due to incorrect check. This patch fixes this issue.Signed-off-by: Marek Szyprowski
29 Jun, 2012
1 commit
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sizes.h is used throughout the AMBA code and drivers, so the header
should be available to everyone in order to driver AMBA/PrimeCell
peripherals behind a PCI bridge where the host can be any platform
(I'm doing it under x86).At this step includes ,
to allow a grace period for both in-tree and out-of-tree drivers.Signed-off-by: Alessandro Rubini
Acked-by: Giancarlo Asnaghi
Acked-by: Linus Walleij
Cc: Alan Cox
Signed-off-by: Russell King
28 Jun, 2012
2 commits
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This patch enabled the tlb flush range support in generic mmu layer.
Most of arch has self tlb flush range support, like ARM/IA64 etc.
X86 arch has no this support in hardware yet. But another instruction
'invlpg' can implement this function in some degree. So, enable this
feather in generic layer for x86 now. and maybe useful for other archs
in further.Generic mmu_gather struct is protected by micro
HAVE_GENERIC_MMU_GATHER. Other archs that has flush range supported
own self mmu_gather struct. So, now this change is safe for them.In future we may unify this struct and related functions on multiple
archs.Thanks for Peter Zijlstra time and time reminder for multiple
architecture code safe!Signed-off-by: Alex Shi
Link: http://lkml.kernel.org/r/1340845344-27557-7-git-send-email-alex.shi@intel.com
Signed-off-by: H. Peter Anvin -
Testing show different CPU type(micro architectures and NUMA mode) has
different balance points between the TLB flush all and multiple invlpg.
And there also has cases the tlb flush change has no any help.This patch give a interface to let x86 vendor developers have a chance
to set different shift for different CPU type.like some machine in my hands, balance points is 16 entries on
Romely-EP; while it is at 8 entries on Bloomfield NHM-EP; and is 256 on
IVB mobile CPU. but on model 15 core2 Xeon using invlpg has nothing
help.For untested machine, do a conservative optimization, same as NHM CPU.
Signed-off-by: Alex Shi
Link: http://lkml.kernel.org/r/1340845344-27557-5-git-send-email-alex.shi@intel.com
Signed-off-by: H. Peter Anvin
26 Jun, 2012
1 commit
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Commit 2603efa31a03 ("bug.h: Fix up powerpc build regression") corrected
the powerpc build case and extended the __ASSEMBLY__ guards, but it also
got caught in pre-processor hell accidentally matching the else case of
CONFIG_BUG resulting in the BUG disabled case tripping up on
-Werror=implicit-function-declaration.It's not possible to __ASSEMBLY__ guard the entire file as architecture
code needs to get at the BUGFLAG_WARNING definition in the GENERIC_BUG
case, but the rest of the CONFIG_BUG=y/n case needs to be guarded.Rather than littering endless __ASSEMBLY__ checks in each of the if/else
cases we just move the BUGFLAG definitions up under their own
GENERIC_BUG test and then shove everything else under one big
__ASSEMBLY__ guard.Build tested on all of x86 CONFIG_BUG=y, CONFIG_BUG=n, powerpc (due to
it's dependence on BUGFLAG definitions in assembly code), and sh (due to
not bringing in linux/kernel.h to satisfy the taint flag definitions used
by the generic bug code).Hopefully that's the end of the corner cases and I can abstain from ever
having to touch this infernal header ever again.Reported-by: Fengguang Wu
Tested-by: Fengguang Wu
Acked-by: Randy Dunlap
Cc: Arnd Bergmann
Signed-off-by: Paul Mundt
Signed-off-by: Linus Torvalds
21 Jun, 2012
2 commits
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* emailed from Andrew Morton : (21 patches)
mm/memblock: fix overlapping allocation when doubling reserved array
c/r: prctl: Move PR_GET_TID_ADDRESS to a proper place
pidns: find_new_reaper() can no longer switch to init_pid_ns.child_reaper
pidns: guarantee that the pidns init will be the last pidns process reaped
fault-inject: avoid call to random32() if fault injection is disabled
Viresh has moved
get_maintainer: Fix --help warning
mm/memory.c: fix kernel-doc warnings
mm: fix kernel-doc warnings
mm: correctly synchronize rss-counters at exit/exec
mm, thp: print useful information when mmap_sem is unlocked in zap_pmd_range
h8300: use the declarations provided by
h8300: fix use of extinct _sbss and _ebss
xtensa: use the declarations provided by
xtensa: use "test -e" instead of bashism "test -a"
xtensa: replace xtensa-specific _f{data,text} by _s{data,text}
memcg: fix use_hierarchy css_is_ancestor oops regression
mm, oom: fix and cleanup oom score calculations
nilfs2: ensure proper cache clearing for gc-inodes
thp: avoid atomic64_read in pmd_read_atomic for 32bit PAE
... -
In the x86 32bit PAE CONFIG_TRANSPARENT_HUGEPAGE=y case while holding the
mmap_sem for reading, cmpxchg8b cannot be used to read pmd contents under
Xen.So instead of dealing only with "consistent" pmdvals in
pmd_none_or_trans_huge_or_clear_bad() (which would be conceptually
simpler) we let pmd_none_or_trans_huge_or_clear_bad() deal with pmdvals
where the low 32bit and high 32bit could be inconsistent (to avoid having
to use cmpxchg8b).The only guarantee we get from pmd_read_atomic is that if the low part of
the pmd was found null, the high part will be null too (so the pmd will be
considered unstable). And if the low part of the pmd is found "stable"
later, then it means the whole pmd was read atomically (because after a
pmd is stable, neither MADV_DONTNEED nor page faults can alter it anymore,
and we read the high part after the low part).In the 32bit PAE x86 case, it is enough to read the low part of the pmdval
atomically to declare the pmd as "stable" and that's true for THP and no
THP, furthermore in the THP case we also have a barrier() that will
prevent any inconsistent pmdvals to be cached by a later re-read of the
*pmd.Signed-off-by: Andrea Arcangeli
Cc: Jonathan Nieder
Cc: Ulrich Obergfell
Cc: Mel Gorman
Cc: Hugh Dickins
Cc: Larry Woodman
Cc: Petr Matousek
Cc: Rik van Riel
Cc: Jan Beulich
Cc: KOSAKI Motohiro
Tested-by: Andrew Jones
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Jun, 2012
1 commit
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The asm-generic/bug.h __ASSEMBLY__ guarding is completely bogus, which
tripped up the powerpc build when the kernel.h include was added:In file included from include/asm-generic/bug.h:5:0,
from arch/powerpc/include/asm/bug.h:127,
from arch/powerpc/kernel/head_64.S:31:
include/linux/kernel.h:44:0: warning: "ALIGN" redefined [enabled by default]
include/linux/linkage.h:57:0: note: this is the location of the previous definition
include/linux/sysinfo.h: Assembler messages:
include/linux/sysinfo.h:7: Error: Unrecognized opcode: `struct'
include/linux/sysinfo.h:8: Error: Unrecognized opcode: `__kernel_long_t'Moving the __ASSEMBLY__ guard up and stashing the kernel.h include under
it fixes this up, as well as covering the case the original fix was
attempting to handle.Tested-by: Stephen Rothwell
Acked-by: Arnd Bergmann
Signed-off-by: Paul Mundt
Signed-off-by: Linus Torvalds
13 Jun, 2012
1 commit
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…h/trivial' into sh-fixes-for-linus
11 Jun, 2012
1 commit
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asm-generic/bug.h uses taint flags that are only defined in
linux/kernel.h, resulting in build failures on platforms that
don't include linux/kernel.h some other way:arch/sh/include/asm/thread_info.h:172:2: error: 'TAINT_WARN' undeclared (first use in this function)
Caused by commit edd63a2763bd ("set_restore_sigmask() is never called
without SIGPENDING (and never should be)").Reported-by: Stephen Rothwell
Cc: Al Viro
Signed-off-by: Paul Mundt
02 Jun, 2012
1 commit
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Pull vfs changes from Al Viro.
"A lot of misc stuff. The obvious groups:
* Miklos' atomic_open series; kills the damn abuse of
->d_revalidate() by NFS, which was the major stumbling block for
all work in that area.
* ripping security_file_mmap() and dealing with deadlocks in the
area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in
general.
* ->encode_fh() switched to saner API; insane fake dentry in
mm/cleancache.c gone.
* assorted annotations in fs (endianness, __user)
* parts of Artem's ->s_dirty work (jff2 and reiserfs parts)
* ->update_time() work from Josef.
* other bits and pieces all over the place.Normally it would've been in two or three pull requests, but
signal.git stuff had eaten a lot of time during this cycle ;-/"Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the
'truncate_range' inode method was removed by the VM changes, the VFS
update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due
to sparse fix added twice, with other changes nearby).* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits)
nfs: don't open in ->d_revalidate
vfs: retry last component if opening stale dentry
vfs: nameidata_to_filp(): don't throw away file on error
vfs: nameidata_to_filp(): inline __dentry_open()
vfs: do_dentry_open(): don't put filp
vfs: split __dentry_open()
vfs: do_last() common post lookup
vfs: do_last(): add audit_inode before open
vfs: do_last(): only return EISDIR for O_CREAT
vfs: do_last(): check LOOKUP_DIRECTORY
vfs: do_last(): make ENOENT exit RCU safe
vfs: make follow_link check RCU safe
vfs: do_last(): use inode variable
vfs: do_last(): inline walk_component()
vfs: do_last(): make exit RCU safe
vfs: split do_lookup()
Btrfs: move over to use ->update_time
fs: introduce inode operation ->update_time
reiserfs: get rid of resierfs_sync_super
reiserfs: mark the superblock as dirty a bit later
...
01 Jun, 2012
3 commits
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Merge misc patches from Andrew Morton:
- the "misc" tree - stuff from all over the map
- checkpatch updates
- fatfs
- kmod changes
- procfs
- cpumask
- UML
- kexec
- mqueue
- rapidio
- pidns
- some checkpoint-restore feature work. Reluctantly. Most of it
delayed a release. I'm still rather worried that we don't have a
clear roadmap to completion for this work.* emailed from Andrew Morton : (78 patches)
kconfig: update compression algorithm info
c/r: prctl: add ability to set new mm_struct::exe_file
c/r: prctl: extend PR_SET_MM to set up more mm_struct entries
c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat
syscalls, x86: add __NR_kcmp syscall
fs, proc: introduce /proc//task//children entry
sysctl: make kernel.ns_last_pid control dependent on CHECKPOINT_RESTORE
aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()
eventfd: change int to __u64 in eventfd_signal()
fs/nls: add Apple NLS
pidns: make killed children autoreap
pidns: use task_active_pid_ns in do_notify_parent
rapidio/tsi721: add DMA engine support
rapidio: add DMA engine support for RIO data transfers
ipc/mqueue: add rbtree node caching support
tools/selftests: add mq_perf_tests
ipc/mqueue: strengthen checks on mqueue creation
ipc/mqueue: correct mq_attr_ok test
ipc/mqueue: improve performance of send/recv
selftests: add mq_open_tests
... -
Previous code was using optimizations which were developed to work well
even on narrow-word CPUs (by today's standards). But Linux runs only on
32-bit and wider CPUs. We can use that.First: using 32x32->64 multiply and trivial 32-bit shift, we can correctly
divide by 10 much larger numbers, and thus we can print groups of 9 digits
instead of groups of 5 digits.Next: there are two algorithms to print larger numbers. One is generic:
divide by 1000000000 and repeatedly print groups of (up to) 9 digits.
It's conceptually simple, but requires an (unsigned long long) /
1000000000 division.Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
manipulates them cleverly and generates groups of 4 decimal digits. It so
happens that it does NOT require long long division.If long is > 32 bits, division of 64-bit values is relatively easy, and we
will use the first algorithm. If long long is > 64 bits (strange
architecture with VERY large long long), second algorithm can't be used,
and we again use the first one.Else (if long is 32 bits and long long is 64 bits) we use second one.
And third: there is a simple optimization which takes fast path not only
for zero as was done before, but for all one-digit numbers.In all tested cases new code is faster than old one, in many cases by 30%,
in few cases by more than 50% (for example, on x86-32, conversion of
12345678). Code growth is ~0 in 32-bit case and ~130 bytes in 64-bit
case.This patch is based upon an original from Michal Nazarewicz.
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Michal Nazarewicz
Signed-off-by: Denys Vlasenko
Cc: Douglas W Jones
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Pull two small kvm fixes from Avi Kivity:
"A build fix for non-kvm archs and a transparent hugepage refcount
bugfix on hosts with 4M pages."* git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: Export asm-generic/kvm_para.h
KVM: MMU: fix huge page adapted on non-PAE host
31 May, 2012
1 commit
-
Signed-off-by: Al Viro
30 May, 2012
1 commit
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When holding the mmap_sem for reading, pmd_offset_map_lock should only
run on a pmd_t that has been read atomically from the pmdp pointer,
otherwise we may read only half of it leading to this crash.PID: 11679 TASK: f06e8000 CPU: 3 COMMAND: "do_race_2_panic"
#0 [f06a9dd8] crash_kexec at c049b5ec
#1 [f06a9e2c] oops_end at c083d1c2
#2 [f06a9e40] no_context at c0433ded
#3 [f06a9e64] bad_area_nosemaphore at c043401a
#4 [f06a9e6c] __do_page_fault at c0434493
#5 [f06a9eec] do_page_fault at c083eb45
#6 [f06a9f04] error_code (via page_fault) at c083c5d5
EAX: 01fb470c EBX: fff35000 ECX: 00000003 EDX: 00000100 EBP:
00000000
DS: 007b ESI: 9e201000 ES: 007b EDI: 01fb4700 GS: 00e0
CS: 0060 EIP: c083bc14 ERR: ffffffff EFLAGS: 00010246
#7 [f06a9f38] _spin_lock at c083bc14
#8 [f06a9f44] sys_mincore at c0507b7d
#9 [f06a9fb0] system_call at c083becd
start len
EAX: ffffffda EBX: 9e200000 ECX: 00001000 EDX: 6228537f
DS: 007b ESI: 00000000 ES: 007b EDI: 003d0f00
SS: 007b ESP: 62285354 EBP: 62285388 GS: 0033
CS: 0073 EIP: 00291416 ERR: 000000da EFLAGS: 00000286This should be a longstanding bug affecting x86 32bit PAE without THP.
Only archs with 64bit large pmd_t and 32bit unsigned long should be
affected.With THP enabled the barrier() in pmd_none_or_trans_huge_or_clear_bad()
would partly hide the bug when the pmd transition from none to stable,
by forcing a re-read of the *pmd in pmd_offset_map_lock, but when THP is
enabled a new set of problem arises by the fact could then transition
freely in any of the none, pmd_trans_huge or pmd_trans_stable states.
So making the barrier in pmd_none_or_trans_huge_or_clear_bad()
unconditional isn't good idea and it would be a flakey solution.This should be fully fixed by introducing a pmd_read_atomic that reads
the pmd in order with THP disabled, or by reading the pmd atomically
with cmpxchg8b with THP enabled.Luckily this new race condition only triggers in the places that must
already be covered by pmd_none_or_trans_huge_or_clear_bad() so the fix
is localized there but this bug is not related to THP.NOTE: this can trigger on x86 32bit systems with PAE enabled with more
than 4G of ram, otherwise the high part of the pmd will never risk to be
truncated because it would be zero at all times, in turn so hiding the
SMP race.This bug was discovered and fully debugged by Ulrich, quote:
----
[..]
pmd_none_or_trans_huge_or_clear_bad() loads the content of edx and
eax.496 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t
*pmd)
497 {
498 /* depend on compiler for an atomic pmd read */
499 pmd_t pmdval = *pmd;// edi = pmd pointer
0xc0507a74 : mov 0x8(%esp),%edi
...
// edx = PTE page table high address
0xc0507a84 : mov 0x4(%edi),%edx
...
// eax = PTE page table low address
0xc0507a8e : mov (%edi),%eax[..]
Please note that the PMD is not read atomically. These are two "mov"
instructions where the high order bits of the PMD entry are fetched
first. Hence, the above machine code is prone to the following race.- The PMD entry {high|low} is 0x0000000000000000.
The "mov" at 0xc0507a84 loads 0x00000000 into edx.- A page fault (on another CPU) sneaks in between the two "mov"
instructions and instantiates the PMD.- The PMD entry {high|low} is now 0x00000003fda38067.
The "mov" at 0xc0507a8e loads 0xfda38067 into eax.
----Reported-by: Ulrich Obergfell
Signed-off-by: Andrea Arcangeli
Cc: Mel Gorman
Cc: Hugh Dickins
Cc: Larry Woodman
Cc: Petr Matousek
Cc: Rik van Riel
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 May, 2012
1 commit
-
Prevents build failures on non-KVM archs.
Tested-by: Geert Uytterhoeven
Signed-off-by: Avi Kivity
27 May, 2012
2 commits
-
This makes actually live up to its promise of
allowing architectures to help tune the string functions that do their
work a word at a time.David had already taken the x86 strncpy_from_user() function, modified
it to work on sparc, and then done the extra work to make it generically
useful. This then expands on that work by making x86 use that generic
version, completing the circle.But more importantly, it fixes up the word-at-a-time interfaces so that
it's now easy to also support things like strnlen_user(), and pretty
much most random string functions.David reports that it all works fine on sparc, and Jonas Bonn reported
that an earlier version of this worked on OpenRISC too. It's pretty
easy for architectures to add support for this and just replace their
private versions with the generic code.* generic-string-functions:
sparc: use the new generic strnlen_user() function
x86: use the new generic strnlen_user() function
lib: add generic strnlen_user() function
word-at-a-time: make the interfaces truly generic
x86: use generic strncpy_from_user routine -
This changes the interfaces in to be a bit more
complicated, but a lot more generic.In particular, it allows us to really do the operations efficiently on
both little-endian and big-endian machines, pretty much regardless of
machine details. For example, if you can rely on a fast population
count instruction on your architecture, this will allow you to make your
optimized file with that.NOTE! The "generic" version in include/asm-generic/word-at-a-time.h is
not truly generic, it actually only works on big-endian. Why? Because
on little-endian the generic algorithms are wasteful, since you can
inevitably do better. The x86 implementation is an example of that.(The only truly non-generic part of the asm-generic implementation is
the "find_zero()" function, and you could make a little-endian version
of it. And if the Kbuild infrastructure allowed us to pick a particular
header file, that would be lovely)The functions are as follows:
- WORD_AT_A_TIME_CONSTANTS: specific constants that the algorithm
uses.- has_zero(): take a word, and determine if it has a zero byte in it.
It gets the word, the pointer to the constant pool, and a pointer to
an intermediate "data" field it can set.This is the "quick-and-dirty" zero tester: it's what is run inside
the hot loops.- "prep_zero_mask()": take the word, the data that has_zero() produced,
and the constant pool, and generate an *exact* mask of which byte had
the first zero. This is run directly *outside* the loop, and allows
the "has_zero()" function to answer the "is there a zero byte"
question without necessarily getting exactly *which* byte is the
first one to contain a zero.If you do multiple byte lookups concurrently (eg "hash_name()", which
looks for both NUL and '/' bytes), after you've done the prep_zero_mask()
phase, the result of those can be or'ed together to get the "either
or" case.- The result from "prep_zero_mask()" can then be fed into "find_zero()"
(to find the byte offset of the first byte that was zero) or into
"zero_bytemask()" (to find the bytemask of the bytes preceding the
zero byte).The existence of zero_bytemask() is optional, and is not necessary
for the normal string routines. But dentry name hashing needs it, so
if you enable DENTRY_WORD_AT_A_TIME you need to expose it.This changes the generic strncpy_from_user() function and the dentry
hashing functions to use these modified word-at-a-time interfaces. This
gets us back to the optimized state of the x86 strncpy that we lost in
the previous commit when moving over to the generic version.Signed-off-by: Linus Torvalds
26 May, 2012
3 commits
-
Pull tile updates from Chris Metcalf:
"These changes cover a range of new arch/tile features and
optimizations. They've been through LKML review and on linux-next for
a month or so. There's also one bug-fix that just missed 3.4, which
I've marked for stable."Fixed up trivial conflict in arch/tile/Kconfig (new added tile Kconfig
entries clashing with the generic timer/clockevents changes).* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
tile: default to tilegx_defconfig for ARCH=tile
tile: fix bug where fls(0) was not returning 0
arch/tile: mark TILEGX as not EXPERIMENTAL
tile/mm/fault.c: Port OOM changes to handle_page_fault
arch/tile: add descriptive text if the kernel reports a bad trap
arch/tile: allow querying cpu module information from the hypervisor
arch/tile: fix hardwall for tilegx and generalize for idn and ipi
arch/tile: support multiple huge page sizes dynamically
mm: add new arch_make_huge_pte() method for tile support
arch/tile: support kexec() for tilegx
arch/tile: support header for cacheflush() syscall
arch/tile: Allow tilegx to build with either 16K or 64K page size
arch/tile: optimize get_user/put_user and friends
arch/tile: support building big-endian kernel
arch/tile: allow building Linux with transparent huge pages enabled
arch/tile: use interrupt critical sections less -
The change adds some infrastructure for managing tile pmd's more generally,
using pte_pmd() and pmd_pte() methods to translate pmd values to and
from ptes, since on TILEPro a pmd is really just a nested structure
holding a pgd (aka pte). Several existing pmd methods are moved into
this framework, and a whole raft of additional pmd accessors are defined
that are used by the transparent hugepage framework.The tile PTE now has a "client2" bit. The bit is used to indicate a
transparent huge page is in the process of being split into subpages.This change also fixes a generic bug where the return value of the
generic pmdp_splitting_flush() was incorrect.Signed-off-by: Chris Metcalf
-
Pull CMA and ARM DMA-mapping updates from Marek Szyprowski:
"These patches contain two major updates for DMA mapping subsystem
(mainly for ARM architecture). First one is Contiguous Memory
Allocator (CMA) which makes it possible for device drivers to allocate
big contiguous chunks of memory after the system has booted.The main difference from the similar frameworks is the fact that CMA
allows to transparently reuse the memory region reserved for the big
chunk allocation as a system memory, so no memory is wasted when no
big chunk is allocated. Once the alloc request is issued, the
framework migrates system pages to create space for the required big
chunk of physically contiguous memory.For more information one can refer to nice LWN articles:
- 'A reworked contiguous memory allocator':
http://lwn.net/Articles/447405/- 'CMA and ARM':
http://lwn.net/Articles/450286/- 'A deep dive into CMA':
http://lwn.net/Articles/486301/- and the following thread with the patches and links to all previous
versions:
https://lkml.org/lkml/2012/4/3/204The main client for this new framework is ARM DMA-mapping subsystem.
The second part provides a complete redesign in ARM DMA-mapping
subsystem. The core implementation has been changed to use common
struct dma_map_ops based infrastructure with the recent updates for
new dma attributes merged in v3.4-rc2. This allows to use more than
one implementation of dma-mapping calls and change/select them on the
struct device basis. The first client of this new infractructure is
dmabounce implementation which has been completely cut out of the
core, common code.The last patch of this redesign update introduces a new, experimental
implementation of dma-mapping calls on top of generic IOMMU framework.
This lets ARM sub-platform to transparently use IOMMU for DMA-mapping
calls if one provides required IOMMU hardware.For more information please refer to the following thread:
http://www.spinics.net/lists/arm-kernel/msg175729.htmlThe last patch merges changes from both updates and provides a
resolution for the conflicts which cannot be avoided when patches have
been applied on the same files (mainly arch/arm/mm/dma-mapping.c)."Acked by Andrew Morton :
"Yup, this one please. It's had much work, plenty of review and I
think even Russell is happy with it."* 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping: (28 commits)
ARM: dma-mapping: use PMD size for section unmap
cma: fix migration mode
ARM: integrate CMA with DMA-mapping subsystem
X86: integrate CMA with DMA-mapping subsystem
drivers: add Contiguous Memory Allocator
mm: trigger page reclaim in alloc_contig_range() to stabilise watermarks
mm: extract reclaim code from __alloc_pages_direct_reclaim()
mm: Serialize access to min_free_kbytes
mm: page_isolation: MIGRATE_CMA isolation functions added
mm: mmzone: MIGRATE_CMA migration type added
mm: page_alloc: change fallbacks array handling
mm: page_alloc: introduce alloc_contig_range()
mm: compaction: export some of the functions
mm: compaction: introduce isolate_freepages_range()
mm: compaction: introduce map_pages()
mm: compaction: introduce isolate_migratepages_range()
mm: page_alloc: remove trailing whitespace
ARM: dma-mapping: add support for IOMMU mapper
ARM: dma-mapping: use alloc, mmap, free from dma_ops
ARM: dma-mapping: remove redundant code and do the cleanup
...Conflicts:
arch/x86/include/asm/dma-mapping.h
25 May, 2012
2 commits
-
Pull KVM changes from Avi Kivity:
"Changes include additional instruction emulation, page-crossing MMIO,
faster dirty logging, preventing the watchdog from killing a stopped
guest, module autoload, a new MSI ABI, and some minor optimizations
and fixes. Outside x86 we have a small s390 and a very large ppc
update.Regarding the new (for kvm) rebaseless workflow, some of the patches
that were merged before we switch trees had to be rebased, while
others are true pulls. In either case the signoffs should be correct
now."Fix up trivial conflicts in Documentation/feature-removal-schedule.txt
arch/powerpc/kvm/book3s_segment.S and arch/x86/include/asm/kvm_para.h.I suspect the kvm_para.h resolution ends up doing the "do I have cpuid"
check effectively twice (it was done differently in two different
commits), but better safe than sorry ;)* 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (125 commits)
KVM: make asm-generic/kvm_para.h have an ifdef __KERNEL__ block
KVM: s390: onereg for timer related registers
KVM: s390: epoch difference and TOD programmable field
KVM: s390: KVM_GET/SET_ONEREG for s390
KVM: s390: add capability indicating COW support
KVM: Fix mmu_reload() clash with nested vmx event injection
KVM: MMU: Don't use RCU for lockless shadow walking
KVM: VMX: Optimize %ds, %es reload
KVM: VMX: Fix %ds/%es clobber
KVM: x86 emulator: convert bsf/bsr instructions to emulate_2op_SrcV_nobyte()
KVM: VMX: unlike vmcs on fail path
KVM: PPC: Emulator: clean up SPR reads and writes
KVM: PPC: Emulator: clean up instruction parsing
kvm/powerpc: Add new ioctl to retreive server MMU infos
kvm/book3s: Make kernel emulated H_PUT_TCE available for "PR" KVM
KVM: PPC: bookehv: Fix r8/r13 storing in level exception handler
KVM: PPC: Book3S: Enable IRQs during exit handling
KVM: PPC: Fix PR KVM on POWER7 bare metal
KVM: PPC: Fix stbux emulation
KVM: PPC: bookehv: Use lwz/stw instead of PPC_LL/PPC_STL for 32-bit fields
... -
Pull GPIO driver changes from Grant Likely:
"Lots of gpio changes, both to core code and drivers.Changes do touch architecture code to remove the need for separate
arm/gpio.h includes in most architectures.Some new drivers are added, and a number of gpio drivers are converted
to use irq_domains for gpio inputs used as interrupts. Device tree
support has been amended to allow multiple gpio_chips to use the same
device tree node.Remaining changes are primarily bug fixes."
* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6: (33 commits)
gpio/generic: initialize basic_mmio_gpio shadow variables properly
gpiolib: Remove 'const' from data argument of gpiochip_find()
gpio/rc5t583: add gpio driver for RICOH PMIC RC5T583
gpiolib: quiet gpiochip_add boot message noise
gpio: mpc8xxx: Prevent NULL pointer deref in demux handler
gpio/lpc32xx: Add device tree support
gpio: Adjust of_xlate API to support multiple GPIO chips
gpiolib: Implement devm_gpio_request_one()
gpio-mcp23s08: dbg_show: fix pullup configuration display
Add support for TCA6424A
gpio/omap: (re)fix wakeups on level-triggered GPIOs
gpio/omap: fix broken context restore for non-OFF mode transitions
gpio/omap: fix missing check in *_runtime_suspend()
gpio/omap: remove cpu_is_omapxxxx() checks from *_runtime_resume()
gpio/omap: remove suspend/resume callbacks
gpio/omap: remove retrigger variable in gpio_irq_handler
gpio/omap: remove saved_wakeup field from struct gpio_bank
gpio/omap: remove suspend_wakeup field from struct gpio_bank
gpio/omap: remove saved_fallingdetect, saved_risingdetect
gpio/omap: remove virtual_irq_start variable
...Conflicts:
drivers/gpio/gpio-samsung.c
23 May, 2012
1 commit
-
Pull perf changes from Ingo Molnar:
"Lots of changes:- (much) improved assembly annotation support in perf report, with
jump visualization, searching, navigation, visual output
improvements and more.- kernel support for AMD IBS PMU hardware features. Notably 'perf
record -e cycles:p' and 'perf top -e cycles:p' should work without
skid now, like PEBS does on the Intel side, because it takes
advantage of IBS transparently.- the libtracevents library: it is the first step towards unifying
tracing tooling and perf, and it also gives a tracing library for
external tools like powertop to rely on.- infrastructure: various improvements and refactoring of the UI
modules and related code- infrastructure: cleanup and simplification of the profiling
targets code (--uid, --pid, --tid, --cpu, --all-cpus, etc.)- tons of robustness fixes all around
- various ftrace updates: speedups, cleanups, robustness
improvements.- typing 'make' in tools/ will now give you a menu of projects to
build and a short help text to explain what each does.- ... and lots of other changes I forgot to list.
The perf record make bzImage + perf report regression you reported
should be fixed."* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (166 commits)
tracing: Remove kernel_lock annotations
tracing: Fix initial buffer_size_kb state
ring-buffer: Merge separate resize loops
perf evsel: Create events initially disabled -- again
perf tools: Split term type into value type and term type
perf hists: Fix callchain ip printf format
perf target: Add uses_mmap field
ftrace: Remove selecting FRAME_POINTER with FUNCTION_TRACER
ftrace/x86: Have x86 ftrace use the ftrace_modify_all_code()
ftrace: Make ftrace_modify_all_code() global for archs to use
ftrace: Return record ip addr for ftrace_location()
ftrace: Consolidate ftrace_location() and ftrace_text_reserved()
ftrace: Speed up search by skipping pages by address
ftrace: Remove extra helper functions
ftrace: Sort all function addresses, not just per page
tracing: change CPU ring buffer state from tracing_cpumask
tracing: Check return value of tracing_dentry_percpu()
ring-buffer: Reset head page before running self test
ring-buffer: Add integrity check at end of iter read
ring-buffer: Make addition of pages in ring buffer atomic
...
22 May, 2012
3 commits
-
Conflicts:
arch/arm/Kconfig
arch/arm/mm/dma-mapping.cSigned-off-by: Marek Szyprowski
-
Pull security subsystem updates from James Morris:
"New notable features:
- The seccomp work from Will Drewry
- PR_{GET,SET}_NO_NEW_PRIVS from Andy Lutomirski
- Longer security labels for Smack from Casey Schaufler
- Additional ptrace restriction modes for Yama by Kees Cook"Fix up trivial context conflicts in arch/x86/Kconfig and include/linux/filter.h
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (65 commits)
apparmor: fix long path failure due to disconnected path
apparmor: fix profile lookup for unconfined
ima: fix filename hint to reflect script interpreter name
KEYS: Don't check for NULL key pointer in key_validate()
Smack: allow for significantly longer Smack labels v4
gfp flags for security_inode_alloc()?
Smack: recursive tramsmute
Yama: replace capable() with ns_capable()
TOMOYO: Accept manager programs which do not start with / .
KEYS: Add invalidation support
KEYS: Do LRU discard in full keyrings
KEYS: Permit in-place link replacement in keyring list
KEYS: Perform RCU synchronisation on keys prior to key destruction
KEYS: Announce key type (un)registration
KEYS: Reorganise keys Makefile
KEYS: Move the key config into security/keys/Kconfig
KEYS: Use the compat keyctl() syscall wrapper on Sparc64 for Sparc32 compat
Yama: remove an unused variable
samples/seccomp: fix dependencies on arch macros
Yama: add additional ptrace scopes
... -
Pull PCI changes from Bjorn Helgaas:
- Host bridge cleanups from Yinghai
- Disable Bus Master bit on PCI device shutdown (kexec-related)
- Stratus ftServer fix
- pci_dev_reset() locking fix
- IvyBridge graphics erratum workaround* tag 'pci-for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (21 commits)
microblaze/PCI: fix "io_offset undeclared" error
x86/PCI: only check for spinlock being held in SMP kernels
resources: add resource_overlaps()
PCI: fix uninitialized variable 'cap_mask'
MAINTAINERS: update PCI git tree and patchwork
PCI: disable Bus Master on PCI device shutdown
PCI: work around IvyBridge internal graphics FLR erratum
x86/PCI: fix unused variable warning in amd_bus.c
PCI: move mutex locking out of pci_dev_reset function
PCI: work around Stratus ftServer broken PCIe hierarchy
x86/PCI: merge pcibios_scan_root() and pci_scan_bus_on_node()
x86/PCI: dynamically allocate pci_root_info for native host bridge drivers
x86/PCI: embed pci_sysdata into pci_root_info on ACPI path
x86/PCI: embed name into pci_root_info struct
x86/PCI: add host bridge resource release for _CRS path
x86/PCI: refactor get_current_resources()
PCI: add host bridge release support
PCI: add generic device into pci_host_bridge struct
PCI: rename pci_host_bridge() to find_pci_root_bridge()
x86/PCI: fix memleak with get_current_resources()
...
21 May, 2012
1 commit
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There are two functions in this asm-generic file. Looking at
other arch which do not use the generic version, these two fcns
are within an #ifdef __KERNEL__ block, so make the generic one
consistent with those.Signed-off-by: Paul Gortmaker
Signed-off-by: Avi Kivity
