Linus Torvalds [Wed, 1 May 2013 15:17:51 +0000 (08:17 -0700)]
Merge branch 'ipc-scalability'
Merge IPC cleanup and scalability patches from Andrew Morton.
This cleans up many of the oddities in the IPC code, uses the list
iterator helpers, splits out locking and adds per-semaphore locks for
greater scalability of the IPC semaphore code.
Most normal user-level locking by now uses futexes (ie pthreads, but
also a lot of specialized locks), but SysV IPC semaphores are apparently
still used in some big applications, either for portability reasons, or
because they offer tracking and undo (and you don't need to have a
special shared memory area for them).
Our IPC semaphore scalability was pitiful. We used to lock much too big
ranges, and we used to have a single ipc lock per ipc semaphore array.
Most loads never cared, but some do. There are some numbers in the
individual commits.
* ipc-scalability:
ipc: sysv shared memory limited to 8TiB
ipc/msg.c: use list_for_each_entry_[safe] for list traversing
ipc,sem: fine grained locking for semtimedop
ipc,sem: have only one list in struct sem_queue
ipc,sem: open code and rename sem_lock
ipc,sem: do not hold ipc lock more than necessary
ipc: introduce lockless pre_down ipcctl
ipc: introduce obtaining a lockless ipc object
ipc: remove bogus lock comment for ipc_checkid
ipc/msgutil.c: use linux/uaccess.h
ipc: refactor msg list search into separate function
ipc: simplify msg list search
ipc: implement MSG_COPY as a new receive mode
ipc: remove msg handling from queue scan
ipc: set EFAULT as default error in load_msg()
ipc: tighten msg copy loops
ipc: separate msg allocation from userspace copy
ipc: clamp with min()
Robin Holt [Wed, 1 May 2013 02:15:54 +0000 (19:15 -0700)]
ipc: sysv shared memory limited to 8TiB
Trying to run an application which was trying to put data into half of
memory using shmget(), we found that having a shmall value below 8EiB-8TiB
would prevent us from using anything more than 8TiB. By setting
kernel.shmall greater than 8EiB-8TiB would make the job work.
In the newseg() function, ns->shm_tot which, at 8TiB is INT_MAX.
[akpm@linux-foundation.org: make ipc/shm.c:newseg()'s numpages size_t, not int] Signed-off-by: Robin Holt <holt@sgi.com> Reported-by: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ipc/msg.c: use list_for_each_entry_[safe] for list traversing
The ipc/msg.c code does its list operations by hand and it open-codes the
accesses, instead of using for_each_entry_[safe].
Signed-off-by: Nikola Pajkovsky <npajkovs@redhat.com> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rik van Riel [Wed, 1 May 2013 02:15:44 +0000 (19:15 -0700)]
ipc,sem: fine grained locking for semtimedop
Introduce finer grained locking for semtimedop, to handle the common case
of a program wanting to manipulate one semaphore from an array with
multiple semaphores.
If the call is a semop manipulating just one semaphore in an array with
multiple semaphores, only take the lock for that semaphore itself.
If the call needs to manipulate multiple semaphores, or another caller is
in a transaction that manipulates multiple semaphores, the sem_array lock
is taken, as well as all the locks for the individual semaphores.
On a 24 CPU system, performance numbers with the semop-multi
test with N threads and N semaphores, look like this:
Rik van Riel [Wed, 1 May 2013 02:15:39 +0000 (19:15 -0700)]
ipc,sem: have only one list in struct sem_queue
Having only one list in struct sem_queue, and only queueing simple
semaphore operations on the list for the semaphore involved, allows us to
introduce finer grained locking for semtimedop.
Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Chegu Vinod <chegu_vinod@hp.com> Cc: Emmanuel Benisty <benisty.e@gmail.com> Cc: Jason Low <jason.low2@hp.com> Cc: Michel Lespinasse <walken@google.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2) While on an Oracle swingbench DSS (data mining) workload the
improvements are not as exciting as with Rik's benchmark, we can see
some positive numbers. For an 8 socket machine the following are the
percentages of %sys time incurred in the ipc lock:
Davidlohr Bueso [Wed, 1 May 2013 02:15:24 +0000 (19:15 -0700)]
ipc: introduce lockless pre_down ipcctl
Various forms of ipc use ipcctl_pre_down() to retrieve an ipc object and
check permissions, mostly for IPC_RMID and IPC_SET commands.
Introduce ipcctl_pre_down_nolock(), a lockless version of this function.
The locking version is retained, yet modified to call the nolock version
without affecting its semantics, thus transparent to all ipc callers.
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Signed-off-by: Rik van Riel <riel@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Chegu Vinod <chegu_vinod@hp.com> Cc: Emmanuel Benisty <benisty.e@gmail.com> Cc: Jason Low <jason.low2@hp.com> Cc: Michel Lespinasse <walken@google.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davidlohr Bueso [Wed, 1 May 2013 02:15:19 +0000 (19:15 -0700)]
ipc: introduce obtaining a lockless ipc object
Through ipc_lock() and therefore ipc_lock_check() we currently return the
locked ipc object. This is not necessary for all situations and can,
therefore, cause unnecessary ipc lock contention.
Introduce analogous ipc_obtain_object() and ipc_obtain_object_check()
functions that only lookup and return the ipc object.
Both these functions must be called within the RCU read critical section.
[akpm@linux-foundation.org: propagate the ipc_obtain_object() errno from ipc_lock()] Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Signed-off-by: Rik van Riel <riel@redhat.com> Reviewed-by: Chegu Vinod <chegu_vinod@hp.com> Acked-by: Michel Lespinasse <walken@google.com> Cc: Emmanuel Benisty <benisty.e@gmail.com> Cc: Jason Low <jason.low2@hp.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davidlohr Bueso [Wed, 1 May 2013 02:15:14 +0000 (19:15 -0700)]
ipc: remove bogus lock comment for ipc_checkid
This series makes the sysv semaphore code more scalable, by reducing the
time the semaphore lock is held, and making the locking more scalable for
semaphore arrays with multiple semaphores.
The first four patches were written by Davidlohr Buesso, and reduce the
hold time of the semaphore lock.
The last three patches change the sysv semaphore code locking to be more
fine grained, providing a performance boost when multiple semaphores in a
semaphore array are being manipulated simultaneously.
On a 24 CPU system, performance numbers with the semop-multi
test with N threads and N semaphores, look like this:
Linus Torvalds [Wed, 1 May 2013 15:04:12 +0000 (08:04 -0700)]
Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"Mostly performance and bug fixes, plus some cleanups. The one new
feature this merge window is a new ioctl EXT4_IOC_SWAP_BOOT which
allows installation of a hidden inode designed for boot loaders."
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (50 commits)
ext4: fix type-widening bug in inode table readahead code
ext4: add check for inodes_count overflow in new resize ioctl
ext4: fix Kconfig documentation for CONFIG_EXT4_DEBUG
ext4: fix online resizing for ext3-compat file systems
jbd2: trace when lock_buffer in do_get_write_access takes a long time
ext4: mark metadata blocks using bh flags
buffer: add BH_Prio and BH_Meta flags
ext4: mark all metadata I/O with REQ_META
ext4: fix readdir error in case inline_data+^dir_index.
ext4: fix readdir error in the case of inline_data+dir_index
jbd2: use kmem_cache_zalloc instead of kmem_cache_alloc/memset
ext4: mext_insert_extents should update extent block checksum
ext4: move quota initialization out of inode allocation transaction
ext4: reserve xattr index for Rich ACL support
jbd2: reduce journal_head size
ext4: clear buffer_uninit flag when submitting IO
ext4: use io_end for multiple bios
ext4: make ext4_bio_write_page() use BH_Async_Write flags
ext4: Use kstrtoul() instead of parse_strtoul()
ext4: defragmentation code cleanup
...
Linus Torvalds [Wed, 1 May 2013 14:44:37 +0000 (07:44 -0700)]
Merge tag 'tag-for-linus-3.10' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf
Pull dma-buf updates from Sumit Semwal:
"Added debugfs support to dma-buf"
* tag 'tag-for-linus-3.10' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf:
dma-buf: Add debugfs support
dma-buf: replace dma_buf_export() with dma_buf_export_named()
Linus Torvalds [Wed, 1 May 2013 14:43:05 +0000 (07:43 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rkuo/linux-hexagon-kernel
Pull Hexagon fixes from Richard Kuo:
"Changes for the Hexagon architecture (and one touching OpenRISC).
They include various fixes to make use of additional arch features and
cleanups. The largest functional change is a cleanup of the signal
and event return paths"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rkuo/linux-hexagon-kernel: (32 commits)
Hexagon: add v4 CS regs to core copyout macro
Hexagon: use correct translation for VMALLOC_START
Hexagon: use correct translations for DMA mappings
Hexagon: fix return value for notify_resume case in do_work_pending
Hexagon: fix signal number for user mem faults
Hexagon: remove two Kconfig entries
arch: remove CONFIG_GENERIC_FIND_NEXT_BIT again
Hexagon: update copyright dates
Hexagon: add translation types for __vmnewmap
Hexagon: fix signal.c compile error
Hexagon: break up user fn/arg register setting
Hexagon: use generic sys_fork, sys_vfork, and sys_clone
Hexagon: fix psp/sp macro
Hexagon: fix up int enable/disable at ret_from_fork
Hexagon: add IOMEM and _relaxed IO macros
Hexagon: switch to using the device type for IO mappings
Hexagon: don't print info for offline CPU's
Hexagon: add support for single-stepping (v4+)
Hexagon: use correct work mask when checking for more work
Hexagon: add support for additional exceptions
...
Linus Torvalds [Wed, 1 May 2013 14:32:21 +0000 (07:32 -0700)]
tty: fix up atime/mtime mess, take three
We first tried to avoid updating atime/mtime entirely (commit b0de59b5733d: "TTY: do not update atime/mtime on read/write"), and then
limited it to only update it occasionally (commit 37b7f3c76595: "TTY:
fix atime/mtime regression"), but it turns out that this was both
insufficient and overkill.
It was insufficient because we let people attach to the shared ptmx node
to see activity without even reading atime/mtime, and it was overkill
because the "only once a minute" means that you can't really tell an
idle person from an active one with 'w'.
So this tries to fix the problem properly. It marks the shared ptmx
node as un-notifiable, and it lowers the "only once a minute" to a few
seconds instead - still long enough that you can't time individual
keystrokes, but short enough that you can tell whether somebody is
active or not.
Linus Torvalds [Wed, 1 May 2013 14:21:43 +0000 (07:21 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull compat cleanup from Al Viro:
"Mostly about syscall wrappers this time; there will be another pile
with patches in the same general area from various people, but I'd
rather push those after both that and vfs.git pile are in."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
syscalls.h: slightly reduce the jungles of macros
get rid of union semop in sys_semctl(2) arguments
make do_mremap() static
sparc: no need to sign-extend in sync_file_range() wrapper
ppc compat wrappers for add_key(2) and request_key(2) are pointless
x86: trim sys_ia32.h
x86: sys32_kill and sys32_mprotect are pointless
get rid of compat_sys_semctl() and friends in case of ARCH_WANT_OLD_COMPAT_IPC
merge compat sys_ipc instances
consolidate compat lookup_dcookie()
convert vmsplice to COMPAT_SYSCALL_DEFINE
switch getrusage() to COMPAT_SYSCALL_DEFINE
switch epoll_pwait to COMPAT_SYSCALL_DEFINE
convert sendfile{,64} to COMPAT_SYSCALL_DEFINE
switch signalfd{,4}() to COMPAT_SYSCALL_DEFINE
make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect
make HAVE_SYSCALL_WRAPPERS unconditional
consolidate cond_syscall and SYSCALL_ALIAS declarations
teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long
get rid of duplicate logics in __SC_....[1-6] definitions
Add debugfs support to make it easier to print debug information
about the dma-buf buffers.
Cc: Dave Airlie <airlied@redhat.com>
[minor fixes on init and warning fix] Cc: Dan Carpenter <dan.carpenter@oracle.com>
[remove double unlock in fail case] Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Sumit Semwal [Fri, 22 Mar 2013 12:52:16 +0000 (18:22 +0530)]
dma-buf: replace dma_buf_export() with dma_buf_export_named()
For debugging purposes, it is useful to have a name-string added
while exporting buffers. Hence, dma_buf_export() is replaced with
dma_buf_export_named(), which additionally takes 'exp_name' as a
parameter.
For backward compatibility, and for lazy exporters who don't wish to
name themselves, a #define dma_buf_export() is also made available,
which adds a __FILE__ instead of 'exp_name'.
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
[Thanks for the idea!] Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Paul Bolle [Thu, 21 Mar 2013 10:13:17 +0000 (11:13 +0100)]
Hexagon: remove two Kconfig entries
The Kconfig entries for HEXAGON_VM and HEXAGON_ANGEL_TRAPS were added,
together with the configuration and makefiles for the Hexagon
architecture, in v3.2. They have never been used. They can safely be
removed.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
[rkuo@codeaurora.org: adjust for line changes in Kconfig] Signed-off-by: Richard Kuo <rkuo@codeaurora.org>
Richard Kuo [Tue, 29 May 2012 22:23:14 +0000 (17:23 -0500)]
Hexagon: Signal and return path fixes
This fixes the return value of sigreturn and moves the work pending check
into a c routine for readability and fixes the loop for multiple pending
signals. Based on feedback from Al Viro.
Linus Torvalds [Wed, 1 May 2013 00:37:43 +0000 (17:37 -0700)]
Merge branch 'akpm' (incoming from Andrew)
Merge third batch of fixes from Andrew Morton:
"Most of the rest. I still have two large patchsets against AIO and
IPC, but they're a bit stuck behind other trees and I'm about to
vanish for six days.
- random fixlets
- inotify
- more of the MM queue
- show_stack() cleanups
- DMI update
- kthread/workqueue things
- compat cleanups
- epoll udpates
- binfmt updates
- nilfs2
- hfs
- hfsplus
- ptrace
- kmod
- coredump
- kexec
- rbtree
- pids
- pidns
- pps
- semaphore tweaks
- some w1 patches
- relay updates
- core Kconfig changes
- sysrq tweaks"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (109 commits)
Documentation/sysrq: fix inconstistent help message of sysrq key
ethernet/emac/sysrq: fix inconstistent help message of sysrq key
sparc/sysrq: fix inconstistent help message of sysrq key
powerpc/xmon/sysrq: fix inconstistent help message of sysrq key
ARM/etm/sysrq: fix inconstistent help message of sysrq key
power/sysrq: fix inconstistent help message of sysrq key
kgdb/sysrq: fix inconstistent help message of sysrq key
lib/decompress.c: fix initconst
notifier-error-inject: fix module names in Kconfig
kernel/sys.c: make prctl(PR_SET_MM) generally available
UAPI: remove empty Kbuild files
menuconfig: print more info for symbol without prompts
init/Kconfig: re-order CONFIG_EXPERT options to fix menuconfig display
kconfig menu: move Virtualization drivers near other virtualization options
Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
relay: use macro PAGE_ALIGN instead of FIX_SIZE
kernel/relay.c: move FIX_SIZE macro into relay.c
kernel/relay.c: remove unused function argument actor
drivers/w1/slaves/w1_ds2760.c: fix the error handling in w1_ds2760_add_slave()
drivers/w1/slaves/w1_ds2781.c: fix the error handling in w1_ds2781_add_slave()
...
Linus Torvalds [Wed, 1 May 2013 00:16:17 +0000 (17:16 -0700)]
Merge tag 'md-3.10' of git://neil.brown.name/md
Pull md fixes from NeilBrown:
"A mixed bag of little fixes. No real new functionality here. Several
patches are tagged for -stable."
* tag 'md-3.10' of git://neil.brown.name/md:
MD: ignore discard request for hard disks of hybid raid1/raid10 array
md: bad block list should default to disabled.
md: raid1/raid10 md devices leak memory when stopping
DM RAID: Add message/status support for changing sync action
MD: Export 'md_reap_sync_thread' function
md: don't update metadata when stopping a read-only array.
md: Allow devices to be re-added to a read-only array.
md/raid10: Allow skipping recovery when clean arrays are assembled
MD: Fix typos in MD documentation
md/raid5: avoid an extra write when writing to a known-bad-block.
md/raid5: Change or of some order to improve efficiency.
md: use set_bit_le and clear_bit_le
md: HOT_DISK_REMOVE shouldn't make a read-auto device active.
md: use common code for all calls to ->hot_remove_disk()
md: never update metadata when array is read-only.
this would confuse user trigger sysrq by upper-case character, which is
inconsistent with the real lower-case character registed key.
This inconsistent help message will also lead more confused when
26 upper-case letters put into use in future.
This patch fix spare sysrq key: "global-regs(y)"
Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
this would confuse user trigger sysrq by upper-case character, which is
inconsistent with the real lower-case character registed key.
This inconsistent help message will also lead more confused when
26 upper-case letters put into use in future.
This patch fix arm etm sysrq key: "etm-buffer-dump(v)"
(This patch also add "-" to separate each sysrq key help word,
instead of spaces)
Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This functionality is needed by any application or package that needs to
reconstruct Linux processes, that is, to start them in any way other than
by means of an "execve()" from an executable file. This includes:
1. Restoring processes from a checkpoint-file (by all potential
user-level checkpointing packages, not only CRIU's).
2. Restarting processes on another node after process migration.
3. Starting duplicated copies of a running process (for reliability
and high-availablity).
4. Starting a process from an executable format that is not supported
by Linux, thus requiring a "manual execve" by a user-level utility.
5. Similarly, starting a process from a networked and/or crypted
executable that, for confidentiality, licensing or other reasons,
may not be written to the local file-systems.
The code that does that was already included in the Linux kernel by the
CRIU group, in the form of "prctl(PR_SET_MM)", but prior to this was
enclosed within their private "#ifdef CONFIG_CHECKPOINT_RESTORE", which is
normally disabled. The patch removes those ifdefs.
Signed-off-by: Amnon Shiloh <u3557@miso.sublimeip.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
menuconfig: print more info for symbol without prompts
When we search a config symbol, if it has no prompt the position of this
symbol in the Kconfig file and it's dependencies are not printed. This
can be inconvenient, especially when it's set to n and we want to find out
why.
the following is an example:
before:
Symbol: GENERIC_SMP_IDLE_THREAD [=y]
Type : boolean
Selected by: X86 [=y]
after:
Symbol: GENERIC_SMP_IDLE_THREAD [=y]
Type : boolean
Defined at arch/Kconfig:213
Selected by: X86 [=y]
Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.com> Signed-off-by: Libo Chen <libo.chen@huawei.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Frysinger [Tue, 30 Apr 2013 22:28:45 +0000 (15:28 -0700)]
init/Kconfig: re-order CONFIG_EXPERT options to fix menuconfig display
The kconfig language requires that dependent options all follow the
menuconfig symbol in order to be collapsed below it. Recently some hidden
options were added below the EXPERT menuconfig, but did not depend on
EXPERT (because hidden options can't). This broke the display. So
re-order all these options, and while we're here stick the PCI quirks
under the EXPERT menu (since it isn't sitting with any related options).
Before this commit, we get:
[*] Configure standard kernel features (expert users) --->
[ ] Sysctl syscall support
[*] Load all symbols for debugging/ksymoops
...
[ ] Embedded system
Now we get the older (and correct) behavior:
[*] Configure standard kernel features (expert users) --->
[ ] Embedded system
And if you go into the expert menu you get the expert options:
[ ] Sysctl syscall support
[*] Load all symbols for debugging/ksymoops
...
Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Tue, 30 Apr 2013 22:28:44 +0000 (15:28 -0700)]
kconfig menu: move Virtualization drivers near other virtualization options
Make virtualization drivers be logically grouped together (physically
near each other) in the kconfig menu by moving "Virtualization drivers"
to be near "Virtio drivers", Microsort Hyper-V, and Xen driver support.
This is just a user-friendly, visual search change.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Alexander Graf <agraf@suse.de> Cc: Stuart Yoder <stuart.yoder@freescale.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The help text for this config is duplicated across the x86, parisc, and
s390 Kconfig.debug files. Arnd Bergman noted that the help text was
slightly misleading and should be fixed to state that enabling this
option isn't a problem when using pre 4.4 gcc.
To simplify the rewording, consolidate the text into lib/Kconfig.debug
and modify it there to be more explicit about when you should say N to
this config.
Also, make the text a bit more generic by stating that this option
enables compile time checks so we can cover architectures which emit
warnings vs. ones which emit errors. The details of how an
architecture decided to implement the checks isn't as important as the
concept of compile time checking of copy_from_user() calls.
While we're doing this, remove all the copy_from_user_overflow() code
that's duplicated many times and place it into lib/ so that any
architecture supporting this option can get the function for free.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Helge Deller <deller@gmx.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/w1/slaves/w1_ds2760.c: fix the error handling in w1_ds2760_add_slave()
Use platform_device_put() instead of platform_device_unregister() if
platform_device_add() fail, and platform_device_del() should be used in
the error handling case after platform_device_add() success.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Greg KH <greg@kroah.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/w1/slaves/w1_ds2781.c: fix the error handling in w1_ds2781_add_slave()
Use platform_device_put() instead of platform_device_unregister() if
platform_device_add() fail, and platform_device_del() should be used in
the error handling case after platform_device_add() success.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Greg KH <greg@kroah.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/w1/slaves/w1_ds2780.c: fix the error handling in w1_ds2780_add_slave()
Use platform_device_put() instead of platform_device_unregister() if
platform_device_add() fail, and platform_device_del() should be used in
the error handling case after platform_device_add() success.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Greg KH <greg@kroah.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/w1/slaves/w1_bq27000.c: fix the error handling in w1_bq27000_add_slave()
Use platform_device_put() instead of platform_device_unregister() if
platform_device_add() fails, and also add the return value check of
platform_device_add_data().
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Greg KH <greg@kroah.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/pps/kc.c:37:1: sparse: symbol 'pps_kc_hardpps_lock' was not declared. Should it be static?
drivers/pps/kc.c:39:19: sparse: symbol 'pps_kc_hardpps_dev' was not declared. Should it be static?
drivers/pps/kc.c:40:5: sparse: symbol 'pps_kc_hardpps_mode' was not declared. Should it be static?
pps: hide more configuration symbols behind CONFIG_PPS
Make CONFIG_PPS_DEBUG and CONFIG_NTP_PPS be hidden if CONFIG_PPS is not
selected, so that we are not prompted for these configuration options if
CONFIG_PPS is not set.
Michal Belczyk [Tue, 30 Apr 2013 22:28:28 +0000 (15:28 -0700)]
nbd: increase default and max request sizes
Raise the default max request size for nbd to 128KB (from 127KB) to get it
4KB aligned. This patch also allows the max request size to be increased
(via /sys/block/nbd<x>/queue/max_sectors_kb) to 32MB.
The patch makes nbd network traffic more efficient by:
- reducing request fragmentation (4KB alignment)
- reducing the number of requests (fewer round trips, less network overhead)
Especially in high latency networks, larger request size can make a dramatic
Signed-off-by: Paul Clements <paul.clements@steeleye.com> Signed-off-by: Michal Belczyk <belczyk@bsd.krakow.pl> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/pid.c: improve flow of a loop inside alloc_pidmap.
find_next_offset() searches for an available "cleaned bit" in the
respective pid bitmap (page), so returns the offset if found, otherwise
it returns a value equals to BITS_PER_PAGE.
For example, suppose find_next_offset didn't find any available bit, so
there's no purpose to call mk_pid (Wasteful Cpu Cycles).
Therefore, I found it could be better to call mk_pid after the checking
(offset < BITS_PER_PAGE) returned sucessfully! Another point: If (offset
< BITS_PER_PAGE) results in a "failure", then mk_pid would be called
again afterwards.
[akpm@linux-foundation.org: simplify code] Signed-off-by: Raphael S. Carvalho <raphael.scarv@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
exec: do not abuse ->cred_guard_mutex in threadgroup_lock()
threadgroup_lock() takes signal->cred_guard_mutex to ensure that
thread_group_leader() is stable. This doesn't look nice, the scope of
this lock in do_execve() is huge.
And as Dave pointed out this can lead to deadlock, we have the
following dependencies:
Change de_thread() to take threadgroup_change_begin() around the
switch-the-leader code and change threadgroup_lock() to avoid
->cred_guard_mutex.
Note that de_thread() can't sleep with ->group_rwsem held, this can
obviously deadlock with the exiting leader if the writer is active, so it
does threadgroup_change_end() before schedule().
Reported-by: Dave Jones <davej@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Rientjes [Tue, 30 Apr 2013 22:28:18 +0000 (15:28 -0700)]
fs, proc: truncate /proc/pid/comm writes to first TASK_COMM_LEN bytes
Currently, a write to a procfs file will return the number of bytes
successfully written. If the actual string is longer than this, the
remainder of the string will not be be written and userspace will
complete the operation by issuing additional write()s.
Hence
$ echo -n "abcdefghijklmnopqrs" > /proc/self/comm
results in
$ cat /proc/$$/comm
pqrs
since the final four bytes were written with a second write() since
TASK_COMM_LEN == 16. This is obviously an undesired result and not
equivalent to prctl(PR_SET_NAME). The implementation should not need to
know the definition of TASK_COMM_LEN.
This patch truncates the string to the first TASK_COMM_LEN bytes and
returns the bytes written as the length of the string written so the
second write() is suppressed.
$ cat /proc/$$/comm
abcdefghijklmno
Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
coredump: change wait_for_dump_helpers() to use wait_event_interruptible()
wait_for_dump_helpers() calls wake_up/kill_fasync from inside the
wait_event-like loop. This is not needed and in fact this is not
strictly correct, we can/should do this only once after we change
pipe->writers. We could even check if it becomes zero.
Change this code to use use wait_event_interruptible(), this can also
help to make this wait freezable.
With this patch we check pipe->readers without pipe_lock(), this is
fine. Once we see pipe->readers == 1 we know that the handler
decremented the counter, this is all we need.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Mandeep Singh Baines <msb@chromium.org> Cc: Neil Horman <nhorman@redhat.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>