Linus Torvalds
4f988f152e
seqlock: add 'raw_seqcount_begin()' function ...
The normal read_seqcount_begin() function will wait for any current
writers to exit their critical region by looping until the sequence
count is even.
That "wait for sequence count to stabilize" is the right thing to do if
the read-locker will just retry the whole operation on contention: no
point in doing a potentially expensive reader sequence if we know at the
beginning that we'll just end up re-doing it all.
HOWEVER. Some users don't actually retry the operation, but instead
will abort and do the operation with proper locking. So the sequence
count case may be the optimistic quick case, but in the presense of
writers you may want to do full locking in order to guarantee forward
progress. The prime example of this would be the RCU name lookup.
And in that case, you may well be better off without the "retry early",
and are in a rush to instead get to the failure handling. Thus this
"raw" interface that just returns the sequence number without testing it
- it just forces the low bit to zero so that read_seqcount_retry() will
always fail such a "active concurrent writer" scenario.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-04 15:13:54 -07:00
Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm
2012-04-15 17:35:19 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
2012-03-28 10:01:29 -07:00
mxs-dma : move the mxs dma.h to a more common place
2012-03-27 00:37:23 +01:00
HSI: hsi: Rework hsi_event interface
2012-04-23 14:23:32 +03:00
mfd: Convert twl6040 to i2c driver, and separate it from twl core
2012-04-16 16:45:34 +02:00
mfd: Fix modular builds of rc5t583 regulator support
2012-04-16 21:27:07 +02:00
The following text was taken from the original review request:
2012-03-24 10:41:37 -07:00
mmc: remove MMC bus legacy suspend/resume method
2012-04-20 20:30:19 -04:00
MTD merge for 3.4
2012-03-30 17:31:56 -07:00
netfilter: ipset: avoid use of kernel-only types
2012-03-26 21:06:30 +02:00
netfilter: ip6_tables: ip6t_ext_hdr is now static inline
2012-04-09 16:29:34 +02:00
nfsd: include cld.h in the headers_install target
2012-04-16 15:19:12 -04:00
pinctrl: include <linux/bug.h> to prevent compile errors
2012-04-11 09:31:01 +02:00
avr32: fix build failures from mis-naming of atmel_nand.h
2012-04-02 14:41:25 -07:00
Add I2C driver for Summit Microelectronics SMB347 Battery Charger.
2012-03-26 20:41:01 +04:00
regulator: Fixes for -rc1
2012-04-04 10:09:30 -07:00
spi: fix spi.h kernel-doc warning
2012-04-27 11:03:38 -06:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
Merge nfs containerization work from Trond's tree
2012-03-26 11:48:54 -04:00
USB: EHCI: fix crash during suspend on ASUS computers
2012-04-24 13:55:43 -07:00
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
2012-03-30 16:45:39 -07:00
apple_bl: Add register/unregister functions
2012-03-22 09:31:55 -04:00
The following text was taken from the original review request:
2012-03-24 10:41:37 -07:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
bitops: introduce for_each_clear_bit()
2012-03-23 16:58:34 -07:00
block: use lockdep_assert_held for queue locking
2012-03-30 12:33:28 +02:00
The following text was taken from the original review request:
2012-03-24 10:41:37 -07:00
cgroup: revert ss_id_lock to spinlock
2012-03-21 17:55:01 -07:00
Remove all #inclusions of asm/system.h
2012-03-28 18:30:03 +01:00
Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-03-29 18:12:23 -07:00
include/ and checkpatch: prefer __scanf to __attribute__((format(scanf,...)
2012-03-23 16:58:36 -07:00
The following text was taken from the original review request:
2012-03-24 10:41:37 -07:00
The following text was taken from the original review request:
2012-03-24 10:41:37 -07:00
cpuidle: power_usage should be declared signed integer
2012-03-30 03:23:30 -04:00
cpumask: remove old cpu_*_map.
2012-03-29 15:38:31 +10:30
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-03-29 14:46:05 -07:00
crc32: bolt on crc32c
2012-03-23 16:58:38 -07:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
crypto: user - Fix size of netlink dump message
2012-03-29 19:52:48 +08:00
Disintegrate and delete asm/system.h
2012-03-28 15:58:21 -07:00
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
2012-03-21 18:55:10 -07:00
common: DMA-mapping: add NON-CONSISTENT attribute
2012-03-28 16:36:44 +02:00
Merge branch 'for-linus-3.4' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf
2012-03-28 15:02:41 -07:00
Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping
2012-04-04 17:13:43 -07:00
dmaengine-fixes for 3.4-rc3
2012-04-10 15:30:16 -07:00
Merge branch 'linux_next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac
2012-03-28 14:24:40 -07:00
efi: Add new variable attributes
2012-04-30 15:30:18 -07:00
ethtool: Remove exception to the requirement of holding RTNL lock
2012-04-06 02:43:12 -04:00
migrate ext2_fs.h guts to fs/ext2/ext2.h
2012-03-31 16:03:16 -04:00
The following text was taken from the original review request:
2012-03-24 10:41:37 -07:00
firewire: restore the device.h include in linux/firewire.h
2012-04-02 14:41:27 -07:00
Merge branch 'akpm' (Andrew's patch-bomb)
2012-04-05 15:30:34 -07:00
fuse: use flexible array in fuse.h
2012-04-12 12:57:08 +02:00
ARM: pxa: fix gpio wakeup setting
2012-04-27 10:46:45 +08:00
GPIO changes for v3.4
2012-03-28 14:08:46 -07:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGE
2012-03-21 17:55:02 -07:00
hugetlbfs: fix alignment of huge page requests
2012-03-21 17:54:59 -07:00
i2c: Update the FSF address
2012-03-26 21:47:19 +02:00
i2c: Update the FSF address
2012-03-26 21:47:19 +02:00
i2c: Update the FSF address
2012-03-26 21:47:19 +02:00
i2c: Update the FSF address
2012-03-26 21:47:19 +02:00
i2c: Update the FSF address
2012-03-26 21:47:19 +02:00
i2c: Update the FSF address
2012-03-26 21:47:19 +02:00
Disintegrate and delete asm/system.h
2012-03-28 15:58:21 -07:00
eql: dont rely on HZ=100
2012-03-27 22:45:26 -04:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
Remove all #inclusions of asm/system.h
2012-03-28 18:30:03 +01:00
irq: Add IRQ_TYPE_DEFAULT for use by PIC drivers
2012-04-23 11:04:29 +10:00
irq_domain: Move irq_virq_count into NOMAP revmap
2012-04-12 00:37:48 -06:00
Merge branch 'for-next' of git://gitorious.org/kernel-hsi/kernel-hsi
2012-04-02 09:50:40 -07:00
kconfig: fix IS_ENABLED to not require all options to be defined
2012-04-12 18:35:58 -07:00
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-03-31 13:34:04 -07:00
NFS client updates for Linux 3.4
2012-03-23 08:53:47 -07:00
x86,kgdb: Fix DEBUG_RODATA limitation using text_poke()
2012-03-29 17:41:25 -05:00
PM / Sleep: Mitigate race between the freezer and request_firmware()
2012-03-28 23:30:28 +02:00
KVM: unmap pages from the iommu when slots are removed
2012-04-11 22:55:25 -03:00
leds-lm3530: support pwm input mode
2012-03-23 16:58:35 -07:00
drivers/leds/leds-lp5521.c: support led pattern data
2012-03-23 16:58:34 -07:00
[SCSI] libsas, libata: fix start of life for a sas ata_port
2012-04-23 12:11:47 +01:00
Add #includes needed to permit the removal of asm/system.h
2012-03-28 18:30:03 +01:00
backlight: new backlight driver for LP855x devices
2012-03-23 16:58:33 -07:00
lp8727_charger: Correct typos on the comment
2012-03-26 20:40:59 +04:00
lsm_audit: don't specify the audit pre/post callbacks in 'struct common_audit_data'
2012-04-03 09:49:59 -07:00
magic.h: move some FS magic numbers into magic.h
2012-03-23 16:58:31 -07:00
memcg: fix performance of mem_cgroup_begin_update_page_stat()
2012-03-21 17:55:02 -07:00
kill mm argument of vm_munmap()
2012-04-21 01:58:20 -04:00
remoteproc/rpmsg: new subsystem
2012-03-27 16:30:09 -07:00
module: move __module_get and try_module_get() out of line.
2012-03-26 12:50:52 +10:30
params: <level>_initcall-like kernel parameters
2012-03-26 12:50:51 +10:30
[SCSI] st: expand ability to write immediate filemarks
2012-03-27 08:26:34 +01:00
net: fix /proc/net/dev regression
2012-04-03 17:23:23 -04:00
set fake_rtable's dst to NULL to avoid kernel Oops
2012-04-24 00:16:24 -04:00
Merge nfs containerization work from Trond's tree
2012-03-26 11:48:54 -04:00
NFSv4: Ensure we do not reuse open owner names
2012-04-20 23:14:28 -04:00
nmi watchdog: do not use cpp symbol in Kconfig
2012-03-23 16:58:31 -07:00
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
2012-03-28 14:41:36 -07:00
The following text was taken from the original review request:
2012-03-24 10:41:37 -07:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
memcg: remove PCG_FILE_MAPPED
2012-03-21 17:55:01 -07:00
Remove all #inclusions of asm/system.h
2012-03-28 18:30:03 +01:00
Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci
2012-03-23 14:02:12 -07:00
perf: Move mmap page data_head offset assertion out of header
2012-03-24 08:46:59 +01:00
pidns: add reboot_pid_ns() to handle the reboot syscall
2012-03-28 17:14:36 -07:00
pipes: add a "packetized pipe" mode for writing
2012-04-29 13:12:42 -07:00
The following text was taken from the original review request:
2012-03-24 10:41:37 -07:00
PM / QoS: add pm_qos_update_request_timeout() API
2012-03-28 23:31:24 +02:00
poll: add poll_requested_events() and poll_does_not_wait() functions
2012-03-23 16:58:38 -07:00
prctl: add PR_{SET,GET}_CHILD_SUBREAPER to allow simple process supervision
2012-03-23 16:58:32 -07:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
radix-tree: introduce bit-optimized iterator
2012-03-28 17:14:37 -07:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
The following text was taken from the original review request:
2012-03-24 10:41:37 -07:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
Remove all #inclusions of asm/system.h
2012-03-28 18:30:03 +01:00
Disintegrate and delete asm/system.h
2012-03-28 15:58:21 -07:00
The following text was taken from the original review request:
2012-03-24 10:08:39 -07:00
seqlock: add 'raw_seqcount_begin()' function
2012-05-04 15:13:54 -07:00
serial/8250_pci: add a "force background timer" flag and use it for the "kt" serial port
2012-04-09 10:38:30 -07:00
net: fix two typos in skbuff.h
2012-05-01 09:40:19 -04:00
Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
2012-03-28 15:04:26 -07:00
smp: add func to IPI cpus based on parameter func
2012-03-28 17:14:35 -07:00
tcp: tcp_sendpages() should call tcp_push() once
2012-04-05 19:04:27 -04:00
Disintegrate and delete asm/system.h
2012-03-28 15:58:21 -07:00
locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage
2012-03-23 13:18:57 +01:00
do not export kernel's NULL #define to userspace
2012-04-14 07:47:49 -07:00
Remove all #inclusions of asm/system.h
2012-03-28 18:30:03 +01:00
memcg swap: use mem_cgroup_uncharge_swap fix
2012-04-05 15:25:51 -07:00
Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-03-29 18:12:23 -07:00
ntp: Fix leap-second hrtimer livelock
2012-03-22 19:43:43 -07:00
ptrace: the killed tracee should not enter the syscall
2012-03-23 16:58:40 -07:00
Remove all #inclusions of asm/system.h
2012-03-28 18:30:03 +01:00
irq: Kill pointless irqd_to_hw export
2012-04-10 22:39:17 -06:00
vgaarb.h: fix build warnings
2012-04-11 09:36:00 +01:00
virtio: drop thaw PM operation
2012-03-31 08:09:50 +05:30
remoteproc/rpmsg: new subsystem
2012-03-27 16:30:09 -07:00
mm: fix up the vmscan stat in vmstat
2012-04-25 21:26:33 -07:00
Remove all #inclusions of asm/system.h
2012-03-28 18:30:03 +01:00
watchdog: Add support for WDIOC_GETTIMELEFT IOCTL in watchdog core
2012-03-27 20:15:37 +02:00
