We can't go around calling all sorts of magic per character functions at
full rate 3G data speed.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'linux-next' of git://git.infradead.org/ubifs-2.6:
UBIFS: fix corruption dump
UBIFS: clean up free space checking
UBIFS: small amendments in the LEB scanning code
UBIFS: dump a little more in case of corruptions
MAINTAINERS: update ahunter's e-mail address
UBIFS: allow more than one volume to be mounted
UBIFS: fix assertion warning
UBIFS: minor spelling and grammar fixes
UBIFS: fix 64-bit divisions in debug print
UBIFS: few spelling fixes
UBIFS: set write-buffer timout to 3-5 seconds
UBIFS: slightly optimize write-buffer timer usage
UBIFS: improve debugging messaged
UBIFS: fix integer overflow warning
* 'for-linus' of git://git.open-osd.org/linux-open-osd:
osdblk: Adjust queue limits to lower device's limits
osdblk: a Linux block device for OSD objects
MAINTAINERS: Add osd maintained files (F:)
exofs: Avoid using file_fsync()
exofs: Remove IBM copyrights
exofs: Fix bio leak in error handling path (sync read)
* 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel: (22 commits)
drm/i915: Fix for LVDS VBT change on IGDNG
drm/i915: Zap the GTT mapping when transitioning from untiled to tiled.
drm/i915: Refactor calls to unmap_mapping_range
drm/i915: Avoid saving/restore the modesetting registers twice in KMS mode
drm: Disable the unused connectors explicitly when resuming with KMS.
drm/i915: Restore the KMS modeset for every activated CRTC
drm/i915: Fix harmless warning from patch merged after i2c rework.
drm/i915: Disable GEM when a broken video BIOS takes up the whole aperture.
drm/i915: Check the LID device to decide whether the LVDS should be initialized
drm/i915: Move lock to more reasonable location
drm/i915: Add gtt_offset to gem object list debugfs output
drm/i915: Remove gtt_bound from drm_i915_gem_object
drm/i915: Disable VGA output when doing DRM_MODE_DPMS_OFF.
drm/i915: crt fetch EDID by DVI-I converter on G4x platform
drm/i915: Don't update display FIFO watermark on IGDNG
drm/i915: Adjust DisplayPort clocks to use 96MHz reference
drm/i915: Make driver less chatty
drm/i915: fix up a raw 64bit divide
drm/i915: enable sdvo lvds scaling function.
drm/i915: Set SSC frequency for 8xx chips correctly
...
exception.txt only explains the code on x86, so it's better to
move it into Documentation/x86 directory.
And also rename it to exception-tables.txt which looks much
more reasonable.
This patch is on top of the previous one.
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update Documentation/exception.txt.
Remove trailing whitespaces in it.
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When building v2.6.31-rc2-344-g69ca06c, the following build errors are
found due to missing includes:
CC [M] fs/fuse/dev.o
fs/fuse/dev.c: In function ‘request_end’:
fs/fuse/dev.c:289: error: ‘BLK_RW_SYNC’ undeclared (first use in this function)
...
fs/nfs/write.c: In function ‘nfs_set_page_writeback’:
fs/nfs/write.c:207: error: ‘BLK_RW_ASYNC’ undeclared (first use in this function)
Signed-off-by: Larry Finger@lwfinger.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
nilfs2: fix disorder in cp count on error during deleting checkpoints
nilfs2: fix lockdep warning between regular file and inode file
nilfs2: fix incorrect KERN_CRIT messages in case of write failures
nilfs2: fix hang problem of log writer which occurs after write failures
nilfs2: remove unlikely directive causing mis-conversion of error code
* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
dma-debug: Fix the overlap() function to be correct and readable
oprofile: reset bt_lost_no_mapping with other stats
x86/oprofile: rename kernel parameter for architectural perfmon to arch_perfmon
signals: declare sys_rt_tgsigqueueinfo in syscalls.h
rcu: Mark Hierarchical RCU no longer experimental
dma-debug: Put all hash-chain locks into the same lock class
dma-debug: fix off-by-one error in overlap function
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (50 commits)
perf report: Add "Fractal" mode output - support callchains with relative overhead rate
perf_counter tools: callchains: Manage the cumul hits on the fly
perf report: Change default callchain parameters
perf report: Use a modifiable string for default callchain options
perf report: Warn on callchain output request from non-callchain file
x86: atomic64: Inline atomic64_read() again
x86: atomic64: Clean up atomic64_sub_and_test() and atomic64_add_negative()
x86: atomic64: Improve atomic64_xchg()
x86: atomic64: Export APIs to modules
x86: atomic64: Improve atomic64_read()
x86: atomic64: Code atomic(64)_read and atomic(64)_set in C not CPP
x86: atomic64: Fix unclean type use in atomic64_xchg()
x86: atomic64: Make atomic_read() type-safe
x86: atomic64: Reduce size of functions
x86: atomic64: Improve atomic64_add_return()
x86: atomic64: Improve cmpxchg8b()
x86: atomic64: Improve atomic64_read()
x86: atomic64: Move the 32-bit atomic64_t implementation to a .c file
x86: atomic64: The atomic64_t data type should be 8 bytes aligned on 32-bit too
perf report: Annotate variable initialization
...
Optimize cond_resched() by removing one conditional.
Currently cond_resched() checks system_state ==
SYSTEM_RUNNING in order to avoid scheduling before the
scheduler is running.
We can however, as per suggestion of Matt, use
PREEMPT_ACTIVE to accomplish that very same.
Suggested-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull the initial preempt_count value into a single
definition site.
Maintainers for: alpha, ia64 and m68k, please have a look,
your arch code is funny.
The header magic is a bit odd, but similar to the KERNEL_DS
one, CPP waits with expanding these macros until the
INIT_THREAD_INFO macro itself is expanded, which is in
arch/*/kernel/init_task.c where we've already included
sched.h so we're good.
Cc: tony.luck@intel.com
Cc: rth@twiddle.net
Cc: geert@linux-m68k.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
IGDNG mobile chip's LVDS data block removes panel fitting
register definition. So this fixes offset for LVDS timing
block parsing. Thanks for Michael Fu to catch this.
Signed-off-by: Zhenyu Wang <zhenyu.z.wang@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
As of 52dc7d32b8, we could leave an old
linear GTT mapping in place, so that apps trying to GTT-mapped write in
tiled data wouldn't get the fence added, and garbage would get displayed.
Signed-off-by: Eric Anholt <eric@anholt.net>
As we call unmap_mapping_range() twice in identical fashion, refactor
and attempt to explain why we need to call unmap_mapping_range().
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
Linus noticed how unclean and buggy the overlap() function is:
- It uses convoluted (and bug-causing) positive checks for
range overlap - instead of using a more natural negative
check.
- Even the positive checks are buggy: a positive intersection
check has four natural cases while we checked only for three,
missing the (addr < start && addr2 == end) case for example.
- The variables are mis-named, making it non-obvious how the
check was done.
- It needlessly uses u64 instead of unsigned long. Since these
are kernel memory pointers and we explicitly exclude highmem
ranges anyway we cannot ever overflow 32 bits, even if we
could. (and on 64-bit it doesnt matter anyway)
All in one, this function needs a total revamp. I used Linus's
suggestions minus the paranoid checks (we cannot overflow really
because if we get totally bad DMA ranges passed far more things
break in the systems than just DMA debugging). I also fixed a
few other small details i noticed.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In KMS mode we now use the normal mode-setting paths to set the modes
back to the current configuration, so we don't need to also run the more
limited non-KMS implementation of modesetting for resume.
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
This is seen on some G41 systems, where the BIOS will consume all but
a few KB of the aperture. This should be bad for all operating systems, as
it means that the OS can't dynamically manage memory between graphics and
the rest of the system, and OSes that did static memory management
statically add memory in addition to the BIOS allocation anyway. So, instead
of working around it, just fail out verbosely.
fd.o bug #21574
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: Fix trace_print_seq()
kprobes: No need to unlock kprobe_insn_mutex
tracing/fastboot: Document the need of initcall_debug
trace_export: Repair missed fields
tracing: Fix stack tracer sysctl handling
In case memory is scarce, we now default to oom_cfqq. Once memory is
available again, we should allocate a new cfqq and stop using oom_cfqq for
a particular io context.
Once a new request comes in, check if we are using oom_cfqq, and if yes,
try to allocate a new cfqq.
Tested the patch by forcing the use of oom_cfqq and upon next request thread
realized that it was using oom_cfqq and it allocated a new cfqq.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
I overlooked SG_DXFER_TO_FROM_DEV support when I converted sg to use
the block layer mapping API (2.6.28).
Douglas Gilbert explained SG_DXFER_TO_FROM_DEV:
http://www.spinics.net/lists/linux-scsi/msg37135.html
=
The semantics of SG_DXFER_TO_FROM_DEV were:
- copy user space buffer to kernel (LLD) buffer
- do SCSI command which is assumed to be of the DATA_IN
(data from device) variety. This would overwrite
some or all of the kernel buffer
- copy kernel (LLD) buffer back to the user space.
The idea was to detect short reads by filling the original
user space buffer with some marker bytes ("0xec" it would
seem in this report). The "resid" value is a better way
of detecting short reads but that was only added this century
and requires co-operation from the LLD.
=
This patch changes the block layer mapping API to support this
semantics. This simply adds another field to struct rq_map_data and
enables __bio_copy_iov() to copy data from user space even with READ
requests.
It's better to add the flags field and kills null_mapped and the new
from_user fields in struct rq_map_data but that approach makes it
difficult to send this patch to stable trees because st and osst
drivers use struct rq_map_data (they were converted to use the block
layer in 2.6.29 and 2.6.30). Well, I should clean up the block layer
mapping API.
zhou sf reported this regiression and tested this patch:
http://www.spinics.net/lists/linux-scsi/msg37128.htmlhttp://www.spinics.net/lists/linux-scsi/msg37168.html
Reported-by: zhou sf <sxzzsf@gmail.com>
Tested-by: zhou sf <sxzzsf@gmail.com>
Cc: stable@kernel.org
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently, blk_scsi_ioctl_init() is not called since it lacks
an initcall marking. This causes the command table to be
unitialized, hence somce commands are block when they should
not have been.
This fixes a regression introduced by commit
018e044689
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Commit 1faa16d228 accidentally broke
the bdi congestion wait queue logic, causing us to wait on congestion
for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
git commit 507e1231 "timer stats: Optimize by adding quick check to
avoid function calls" added one wrong check so that one unnecessary
function call isn't elimated.
time_stats_account_hrtimer() checks if timer->start_pid isn't
initialized in order to find out if timer_stats_update_stats() should
be called. However start_pid is initialized with -1 instead of 0, so
that the function call always happens.
Check timer->start_site like in timer_stats_account_timer() to fix
this.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The timer migration expiry check should prevent the migration of a
timer to another CPU when the timer expires before the next event is
scheduled on the other CPU. Migrating the timer might delay it because
we can not reprogram the clock event device on the other CPU. But the
code implementing that check has two flaws:
- for !HIGHRES the check compares the expiry value with the clock
events device expiry value which is wrong for CLOCK_REALTIME based
timers.
- the check is racy. It holds the hrtimer base lock of the target CPU,
but the clock event device expiry value can be modified
nevertheless, e.g. by an timer interrupt firing.
The !HIGHRES case is easy to fix as we can enqueue the timer on the
cpu which was selected by the load balancer. It runs the idle
balancing code once per jiffy anyway. So the maximum delay for the
timer is the same as when we keep the tick on the current cpu going.
In the HIGHRES case we can get the next expiry value from the hrtimer
cpu_base of the target CPU and serialize the update with the cpu_base
lock. This moves the lock section in hrtimer_interrupt() so we can set
next_event to KTIME_MAX while we are handling the expired timers and
set it to the next expiry value after we handled the timers under the
base lock. While the expired timers are processed timer migration is
blocked because the expiry time of the timer is always <= KTIME_MAX.
Also remove the now useless clockevents_get_next_event() function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The timer migration code needs to check whether the expiry time of the
timer is before the programmed clock event expiry time when the timer
is enqueued on another CPU because we can not reprogram the timer
device on the other CPU. The current logic checks the expiry time even
if we enqueue on the current CPU when nohz_get_load_balancer() returns
current CPU. This might lead to an endless loop in the expiry check
code when the expiry time of the timer is before the current
programmed next event.
Check whether nohz_get_load_balancer() returns current CPU and skip
the expiry check if this is the case.
The bug was triggered from the networking code. The patch fixes the
regression http://bugzilla.kernel.org/show_bug.cgi?id=13738
(Soft-Lockup/Race in networking in 2.6.31-rc1+195)
Cc: Arun Bharadwaj <arun@linux.vnet.ibm.com
Tested-by: Joao Correia <joaomiguelcorreia@gmail.com>
Tested-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The bt_lost_no_mapping is not getting reset at the start of a
profiling run, thus the oprofiled.log shows erroneous values for this
statistic. The attached patch fixes this problem.
Signed-off-by: Maynard Johnson <maynardj@us.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* fix/asoc:
ASoC: Fix wm8753 register cache size and initialization
ASoC: add locking to mpc5200-psc-ac97 driver
ASoC: Fix mpc5200-psc-ac97 to ensure the data ready bit is cleared
ASoC: Fix register cache initialisation for WM8753
init_rt_rq() initializes only rq->rt.pushable_tasks, and not the
pushable_tasks field of the passed rt_rq. The plist is not used
uninitialized since the only pushable_tasks plists used are the
ones of root rt_rqs; anyway reinitializing the list on every group
creation corrupts the root plist, losing its previous contents.
Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090615185638.GK21741@gandalf.sssup.it>
CC: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The sched_stat fields are currently not reset upon fork.
Ingo's recent commit 6c594c21fc
did reset nr_migrations, but it didn't reset any of the
others.
This patch resets all sched_stat fields on fork.
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <193b0f820907090457s7a3662f4gcdecdc22fcae857b@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fixes an easily triggerable BUG() when setting process affinities.
Make sure to count the number of migratable tasks in the same place:
the root rt_rq. Otherwise the number doesn't make sense and we'll hit
the BUG in set_cpus_allowed_rt().
Also, make sure we only count tasks, not groups (this is probably
already taken care of by the fact that rt_se->nr_cpus_allowed will be 0
for groups, but be more explicit)
Tested-by: Thomas Gleixner <tglx@linutronix.de>
CC: stable@kernel.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Gregory Haskins <ghaskins@novell.com>
LKML-Reference: <1247067476.9777.57.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
[WATCHDOG] w83627hf_wdt.c: add support for the W83627EHF support
[WATCHDOG] SA1100 watchdog maximum timeout
[WATCHDOG] w83697ug, fix lock imbalance
[WATCHDOG] drivers/watchdog/bcm47xx_wdt.c: Remove unnecessary semicolons
Remove call to the mx3fb_set_par() and the mx3fb_blank() before the
register_framebuffer().
This fixes a problem with uninitialized the fb_info->mm_lock mutex
introduced by the commit 537a1bf059 " fbdev: add mutex for fb_mmap
locking"
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove call to the fb_set_par() before the register_framebuffer().
This fixes a problem with uninitialized the fb_info->mm_lock mutex
introduced by the commit 537a1bf059 " fbdev: add mutex for fb_mmap
locking"
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: when ATTR_READONLY is set, only clear write bits on non-directories
cifs: remove cifsInodeInfo->inUse counter
cifs: convert cifs_get_inode_info and non-posix readdir to use cifs_iget
[CIFS] update cifs version number
cifs: add and use CIFSSMBUnixSetFileInfo for setattr calls
cifs: make a separate function for filling out FILE_UNIX_BASIC_INFO
cifs: rename CIFSSMBUnixSetInfo to CIFSSMBUnixSetPathInfo
cifs: add pid of initiating process to spnego upcall info
cifs: fix regression with O_EXCL creates and optimize away lookup
cifs: add new cifs_iget function and convert unix codepath to use it
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (29 commits)
cxgb3: Fix crash caused by stashing wrong netdev_queue
ixgbe: Fix coexistence of FCoE and Flow Director in 82599
memory barrier: adding smp_mb__after_lock
net: adding memory barrier to the poll and receive callbacks
netpoll: Fix carrier detection for drivers that are using phylib
includecheck fix: include/linux, rfkill.h
p54: tx refused but queue active
Atheros Kconfig needs to be dependent on WLAN_80211
mac80211: fix docbook
mac80211_hwsim: avoid NULL access
ssb: Add support for 4318E
b43: Add support for 4318E
zd1211rw: adding SONY IFU-WLM2 (054c:0257) as a zd1211b device
zd1211rw: 07b8:6001 is a ZD1211B
r6040: bump driver version to 0.24 and date to 08 July 2009
r6040: restore MIER register correctly when IRQ line is shared
ipv4: Fix fib_trie rebalancing, part 4 (root thresholds)
davinci_emac: fix kernel oops when changing MAC address while interface is down
igb: set lan id prior to configuring phy
mac80211: minstrel: avoid accessing negative indices in rix_to_ndx()
...
Looks like the change in ad361c9884
wasn't compile tested.
Signed-off-by: Dave Jones <davej@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The short name of the achitecture is 'arch_perfmon'. This patch
changes the kernel parameter to use this name.
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit c3a8c5b6 ("cxgb3: move away from LLTX") exposed a bug in how
cxgb3 looks up the netdev_queue it stashes away in a qset during
initialization. For multiport devices, the TX queue index it uses is
offset by the first_qset index of each port. This leads to a crash
once LLTX is removed, since hard_start_xmit is called with one TX
queue lock held, while the TX reclaim timer task grabs a different
(wrong) TX queue lock when it frees skbs.
Fix this by removing the first_qset offset used to look up the TX
queue passed into t3_sge_alloc_qset() from setup_sge_qsets().
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Acked-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix coexistence of Fiber Channel over Ethernet (FCoE) and Flow Director (FDIR)
in 82599 and remove the disabling of FDIR when FCoE is enabled.
Currently, FDIR is turned off when FCoE is enabled under the assumption that
FCoE is always enabled with DCB being turned on. However, FDIR does not have
to be turned off all the time when FCoE is enabled since FCoE can be enabled
without DCB being turned on, e.g., use link pause only. This patch makes sure
that when DCB is turned on or off, FDIR is turned on or off correspondingly;
and when FCoE is enabled, it does not disable FDIR, rather, it will have FDIR
set up properly so FCoE and FDIR can coexist regardless of DCB being on or off.
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adding smp_mb__after_lock define to be used as a smp_mb call after
a lock.
Making it nop for x86, since {read|write|spin}_lock() on x86 are
full memory barriers.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adding memory barrier after the poll_wait function, paired with
receive callbacks. Adding fuctions sock_poll_wait and sk_has_sleeper
to wrap the memory barrier.
Without the memory barrier, following race can happen.
The race fires, when following code paths meet, and the tp->rcv_nxt
and __add_wait_queue updates stay in CPU caches.
CPU1 CPU2
sys_select receive packet
... ...
__add_wait_queue update tp->rcv_nxt
... ...
tp->rcv_nxt check sock_def_readable
... {
schedule ...
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible(sk->sk_sleep)
...
}
If there was no cache the code would work ok, since the wait_queue and
rcv_nxt are opposit to each other.
Meaning that once tp->rcv_nxt is updated by CPU2, the CPU1 either already
passed the tp->rcv_nxt check and sleeps, or will get the new value for
tp->rcv_nxt and will return with new data mask.
In both cases the process (CPU1) is being added to the wait queue, so the
waitqueue_active (CPU2) call cannot miss and will wake up CPU1.
The bad case is when the __add_wait_queue changes done by CPU1 stay in its
cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 will then
endup calling schedule and sleep forever if there are no more data on the
socket.
Calls to poll_wait in following modules were ommited:
net/bluetooth/af_bluetooth.c
net/irda/af_irda.c
net/irda/irnet/irnet_ppp.c
net/mac80211/rc80211_pid_debugfs.c
net/phonet/socket.c
net/rds/af_rds.c
net/rfkill/core.c
net/sunrpc/cache.c
net/sunrpc/rpc_pipe.c
net/tipc/socket.c
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cifs: when ATTR_READONLY is set, only clear write bits on non-directories
On windows servers, ATTR_READONLY apparently either has no meaning or
serves as some sort of queue to certain applications for unrelated
behavior. This MS kbase article has details:
http://support.microsoft.com/kb/326549/
Don't clear the write bits directory mode when ATTR_READONLY is set.
Reported-by: pouchat@peewiki.net
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
