This code is becoming duplicated in many places. So let's consolidate
it into a handy macro that is known to be right and available for reuse.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add debug uart support for MSM8974. This patch adds a Kconfig
entry and the base address for the debug uart.
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Create the hidden config DEBUG_MSM_UART and clean-up
the default selection for CONFIG_DEBUG_LL_INCLUDE.
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch proposes to remove the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The memory pinning code in uaccess_with_memcpy.c does not check
for HugeTLB or THP pmds, and will enter an infinite loop should
a __copy_to_user or __clear_user occur against a huge page.
This patch adds detection code for huge pages to pin_page_for_write.
As this code can be executed in a fast path it refers to the actual
pmds rather than the vma. If a HugeTLB or THP is found (they have
the same pmd representation on ARM), the page table spinlock is
taken to prevent modification whilst the page is pinned.
On ARM, huge pages are only represented as pmds, thus no huge pud
checks are performed. (For huge puds one would lock the page table
in a similar manner as in the pmd case).
Two helper functions are introduced; pmd_thp_or_huge will check
whether or not a page is huge or transparent huge (which have the
same pmd layout on ARM), and pmd_hugewillfault will detect whether
or not a page fault will occur on write to the page.
Running the following test (with the chunking from read_zero
removed):
$ dd if=/dev/zero of=/dev/null bs=10M count=1024
Gave: 2.3 GB/s backed by normal pages,
2.9 GB/s backed by huge pages,
5.1 GB/s backed by huge pages, with page mask=HPAGE_MASK.
After some discussion, it was decided not to adopt the HPAGE_MASK,
as this would have a significant detrimental effect on the overall
system latency due to page_table_lock being held for too long.
This could be revisited if split huge page locks are adopted.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The work-around for A15 errata 798181 is not needed if appropriate ECO
fixes have been applied to r3p2 and earlier core revisions. This can be
checked by reading REVIDR register bits 4 and 9. If only bit 4 is set,
then the IPI broadcast can be skipped.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Our spinlocks are only 32-bit (2x16-bit tickets) and, on processors
with 64-bit atomic instructions, cmpxchg64 makes use of the double-word
exclusive accessors.
This patch wires up the cmpxchg-based lockless lockref implementation
for ARM.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch introduces cmpxchg64_relaxed for arm, which performs a 64-bit
cmpxchg operation without barrier semantics. cmpxchg64_local is updated
to use the new operation.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Our cmpxchg64 macros are wrappers around atomic64_cmpxchg. Whilst this is
great for code re-use, there is a case for barrier-less cmpxchg where it
is known to be safe (for example cmpxchg64_local and cmpxchg-based
lockrefs).
This patch introduces a 64-bit cmpxchg implementation specifically
for the cmpxchg64_* macros, so that it can be later used by the lockref
code.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This implements output of debug messages on efm32 SoCs.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
With LPAE enabled, physical address space is larger than 4GB. Allow mapping any
part of it via /dev/mem by using PHYS_MASK to determine valid range.
PHYS_MASK covers 40 bits with LPAE enabled and 32 bits otherwise.
Reported-by: Vassili Karpov <av1474@comtv.ru>
Signed-off-by: Sergey Dyasly <dserrg@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that we can deal with nested NMI due to IRET re-enabling NMIs and
can deal with faults from NMI by making sure we preserve CR2 over NMIs
we can in fact simply access user-space memory from NMI context.
So rewrite copy_from_user_nmi() to use __copy_from_user_inatomic() and
rework the fault path to do the minimal required work before taking
the in_atomic() fault handler.
In particular avoid perf_sw_event() which would make perf recurse on
itself (it should be harmless as our recursion protections should be
able to deal with this -- but why tempt fate).
Also rename notify_page_fault() to kprobes_fault() as that is a much
better name; there is no notifier in it and its specific to kprobes.
Don measured that his worst case NMI path shrunk from ~300K cycles to
~150K cycles.
Cc: Stephane Eranian <eranian@google.com>
Cc: jmario@redhat.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: dave.hansen@linux.intel.com
Tested-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131024105206.GM2490@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Oleg complained about the excessive 0-ing in perf_event_mmap_event(),
so try and be smarter about it while keeping it fairly fool proof and
avoid leaking random bits out to userspace.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-8jirlm99m6if2z13wd6rbyu6@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf_event_mmap_event() does kzalloc(PATH_MAX + sizeof(u64)) to
ensure we can align the size later. However this means that we
actually allocate PAGE_SIZE * 2 buffer, seems too much.
Change this code to allocate PATH_MAX==PAGE_SIZE bytes, but tell
d_path() to not use the last sizeof(u64) bytes.
Note: it is not clear why do we need __GFP_ZERO, see the next patch.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131016201004.GC23214@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1. perf_event_mmap(vma) is never called with a gate_vma-like arg,
remove the "if (!vma->vm_mm)" code.
2. arch_vma_name() can use the chached value of mmap_event->vma.
3. Change the code to not call arch_vma_name() twice.
4. Purely cosmetic, but since we use "goto got_name" all the time
remove "else" from "[stack]" branch just for symmetry.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131016200945.GB23214@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
throttle_cfs_rq() doesn't check to make sure that period_timer is running,
and while update_curr/assign_cfs_runtime does, a concurrently running
period_timer on another cpu could cancel itself between this cpu's
update_curr and throttle_cfs_rq(). If there are no other cfs_rqs running
in the tg to restart the timer, this causes the cfs_rq to be stranded
forever.
Fix this by calling __start_cfs_bandwidth() in throttle if the timer is
inactive.
(Also add some sched_debug lines for cfs_bandwidth.)
Tested: make a run/sleep task in a cgroup, loop switching the cgroup
between 1ms/100ms quota and unlimited, checking for timer_active=0 and
throttled=1 as a failure. With the throttle_cfs_rq() change commented out
this fails, with the full patch it passes.
Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181632.22647.84174.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, group entity load-weights are initialized to zero. This
admits some races with respect to the first time they are re-weighted in
earlty use. ( Let g[x] denote the se for "g" on cpu "x". )
Suppose that we have root->a and that a enters a throttled state,
immediately followed by a[0]->t1 (the only task running on cpu[0])
blocking:
put_prev_task(group_cfs_rq(a[0]), t1)
put_prev_entity(..., t1)
check_cfs_rq_runtime(group_cfs_rq(a[0]))
throttle_cfs_rq(group_cfs_rq(a[0]))
Then, before unthrottling occurs, let a[0]->b[0]->t2 wake for the first
time:
enqueue_task_fair(rq[0], t2)
enqueue_entity(group_cfs_rq(b[0]), t2)
enqueue_entity_load_avg(group_cfs_rq(b[0]), t2)
account_entity_enqueue(group_cfs_ra(b[0]), t2)
update_cfs_shares(group_cfs_rq(b[0]))
< skipped because b is part of a throttled hierarchy >
enqueue_entity(group_cfs_rq(a[0]), b[0])
...
We now have b[0] enqueued, yet group_cfs_rq(a[0])->load.weight == 0
which violates invariants in several code-paths. Eliminate the
possibility of this by initializing group entity weight.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131016181627.22647.47543.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
__start_cfs_bandwidth calls hrtimer_cancel while holding rq->lock,
waiting for the hrtimer to finish. However, if sched_cfs_period_timer
runs for another loop iteration, the hrtimer can attempt to take
rq->lock, resulting in deadlock.
Fix this by ensuring that cfs_b->timer_active is cleared only if the
_latest_ call to do_sched_cfs_period_timer is returning as idle. Then
__start_cfs_bandwidth can just call hrtimer_try_to_cancel and wait for
that to succeed or timer_active == 1.
Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181622.22647.16643.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hrtimer_expires_remaining does not take internal hrtimer locks and thus
must be guarded against concurrent __hrtimer_start_range_ns (but
returning HRTIMER_RESTART is safe). Use cfs_b->lock to make it safe.
Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181617.22647.73829.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When we transition cfs_bandwidth_used to false, any currently
throttled groups will incorrectly return false from cfs_rq_throttled.
While tg_set_cfs_bandwidth will unthrottle them eventually, currently
running code (including at least dequeue_task_fair and
distribute_cfs_runtime) will cause errors.
Fix this by turning off cfs_bandwidth_used only after unthrottling all
cfs_rqs.
Tested: toggle bandwidth back and forth on a loaded cgroup. Caused
crashes in minutes without the patch, hasn't crashed with it.
Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: pjt@google.com
Link: http://lkml.kernel.org/r/20131016181611.22647.80365.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
OK, so what I'm actually seeing on my WSM is that sched/clock.c is
'broken' for the purpose we're using it for.
What triggered it is that my WSM-EP is broken :-(
[ 0.001000] tsc: Fast TSC calibration using PIT
[ 0.002000] tsc: Detected 2533.715 MHz processor
[ 0.500180] TSC synchronization [CPU#0 -> CPU#6]:
[ 0.505197] Measured 3 cycles TSC warp between CPUs, turning off TSC clock.
[ 0.004000] tsc: Marking TSC unstable due to check_tsc_sync_source failed
For some reason it consistently detects TSC skew, even though NHM+
should have a single clock domain for 'reasonable' systems.
This marks sched_clock_stable=0, which means that we do fancy stuff to
try and get a 'sane' clock. Part of this fancy stuff relies on the tick,
clearly that's gone when NOHZ=y. So for idle cpus time gets stuck, until
it either wakes up or gets kicked by another cpu.
While this is perfectly fine for the scheduler -- it only cares about
actually running stuff, and when we're running stuff we're obviously not
idle. This does somewhat break down for perf which can trigger events
just fine on an otherwise idle cpu.
So I've got NMIs get get 'measured' as taking ~1ms, which actually
don't last nearly that long:
<idle>-0 [013] d.h. 886.311970: rcu_nmi_enter <-do_nmi
...
<idle>-0 [013] d.h. 886.311997: perf_sample_event_took: HERE!!! : 1040990
So ftrace (which uses sched_clock(), not the fancy bits) only sees
~27us, but we measure ~1ms !!
Now since all this measurement stuff lives in x86 code, we can actually
fix it.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: mingo@kernel.org
Cc: dave.hansen@linux.intel.com
Cc: eranian@google.com
Cc: Don Zickus <dzickus@redhat.com>
Cc: jmario@redhat.com
Cc: acme@infradead.org
Link: http://lkml.kernel.org/r/20131017133350.GG3364@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The PPC64 people noticed a missing memory barrier and crufty old
comments in the perf ring buffer code. So update all the comments and
add the missing barrier.
When the architecture implements local_t using atomic_long_t there
will be double barriers issued; but short of introducing more
conditional barrier primitives this is the best we can do.
Reported-by: Victor Kaplansky <victork@il.ibm.com>
Tested-by: Victor Kaplansky <victork@il.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: michael@ellerman.id.au
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: anton@samba.org
Cc: benh@kernel.crashing.org
Link: http://lkml.kernel.org/r/20131025173749.GG19466@laptop.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The CS2 region contains the Assabet board configuration and status
registers, which are 32-bit. Unfortunately, some boot loaders do not
configure this region correctly, leaving it setup as a 16-bit region.
Fix this.
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This updates the h3600 defconfig against the latest kernel with
some small options coming and going due to Kconfig structure,
then modernize it to:
- Configure for low latency preemptive kernel
- Configure for tickless idle
- Enable HRtimers
Tested on the iPAQ h3630.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The SA1100 was implementing its own variants of gpio_get_value()
and gpio_set_value() and only selectively falling back to
gpiolib for extended (EGPIO) handling. However the driver in
gpio/gpio-sa1100.c already handles the same functionality for
these lines, yet remain unused.
The only upside would be things like a timing-critical hotpath
on bit-banged GPIO, but that kind of things does not seem to
happen on these GPIOs, so it is not worth having the extra
complexity.
Tested with some buttons on the Compaq iPAQ H3630.
Cc: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When removing the complex GPIO interface from the SA1100 machines,
we also removed the implicit #includes for a few header files
that was included by <linux/gpio.h> thru <mach/gpio.h>, causing
a compile warning on the simpad boardfile, as <asm/irq.h> was no
longer #included, as follows:
./../arch/arm/include/asm/irq.h:9:0: warning: "NR_IRQS" redefined
[enabled by default]
#define NR_IRQS NR_IRQS_LEGACY
^
In file included from ../../arch/arm/mach-sa1100/simpad.c:29:0:
../../arch/arm/mach-sa1100/include/mach/irqs.h:87:0: note: this is the
location of the previous definition
#define NR_IRQS (IRQ_BOARD_START + NR_IRQS_LOCOMO)
This resolves the problem by explicitly including <asm/irq.h>
into the simpad boardfile.
Reported-by: Olof Johansson <olof@lixom.net>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Cc: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than return true/false indicating whether there was budget left, return
the total packets cleaned. This currently has no use, but will be used in a
following patch which enables CONFIG_NET_RX_BUSY_POLL support in order to track
how many packets were cleaned during the busy poll as part of the extended
statistics.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
dmab->area and addr fields should be cleared at the head of
snd_malloc_dev_iram() as especially dmab->area is used to indicate the
allocation failure / fallback.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Commit 'f52bb72254'
Author: Sricharan R <r.sricharan@ti.com>
ARM: mm: Correct virt_to_phys patching for 64 bit physical addresses
introduced a __ARMEB__ macro usage in a new place, but missed the second
underscore. So correcting it here.
Also a explicit .align keyword is needed for the label with .long
data-type to be aligned on the 4 byte boundary. Otherwise this can
cause problem for thumb2 build. So adding it here.
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds ixgbevf_rx_skb in line with how ixgbe handles the variations on
how packets can be received. It will be extended in a following patch for
CONFIG_NET_RX_BUSY_POLL support.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Neaten and shorten the code using the new fb_<level> macros.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Add fb_<level> convenience macros for emitting the
"fb%d: ", struct fb_info->node value.
Neatens and shortens the code a bit.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
This patch removes the unnecessary display of PCIe bandwidth twice. Since the
ixgbe_check_minimum_link does a better job, and ensures accurate detection on
even complex chains, this older check is no longer necessary.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
The dmi_list array is initialized using gnu designated initializers, and
therefore may contain fewer explicitly defined entries as there are
elements in it. This is because the enum above with M_xyz constants
contains more items than the designated initializer. Those elements not
explicitly initialized are implicitly set to 0.
Now efifb_setup() loops through all these array elements, and performs
a strcmp on each item. For non explicitly initialized elements this will
be a null pointer:
This patch swaps the check order in the if statement, thus checks first
whether dmi_list[i].base is null.
Signed-off-by: James Bates <james.h.bates@gmail.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
This patch updates the ixgbe_check_minimum_link function to correctly show that
there is some minor loss of encoding, even though we don't calculate it in the
max GT/s equation. It is small enough to not bother, but is better to report it
than not.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
A THP PMD update is accounted for as 512 pages updated in vmstat. This is
large difference when estimating the cost of automatic NUMA balancing and
can be misleading when comparing results that had collapsed versus split
THP. This patch addresses the accounting issue.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-10-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
THP migration uses the page lock to guard against parallel allocations
but there are cases like this still open
Task A Task B
--------------------- ---------------------
do_huge_pmd_numa_page do_huge_pmd_numa_page
lock_page
mpol_misplaced == -1
unlock_page
goto clear_pmdnuma
lock_page
mpol_misplaced == 2
migrate_misplaced_transhuge
pmd = pmd_mknonnuma
set_pmd_at
During hours of testing, one crashed with weird errors and while I have
no direct evidence, I suspect something like the race above happened.
This patch extends the page lock to being held until the pmd_numa is
cleared to prevent migration starting in parallel while the pmd_numa is
being cleared. It also flushes the old pmd entry and orders pagetable
insertion before rmap insertion.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-9-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There are three callers of task_numa_fault():
- do_huge_pmd_numa_page():
Accounts against the current node, not the node where the
page resides, unless we migrated, in which case it accounts
against the node we migrated to.
- do_numa_page():
Accounts against the current node, not the node where the
page resides, unless we migrated, in which case it accounts
against the node we migrated to.
- do_pmd_numa_page():
Accounts not at all when the page isn't migrated, otherwise
accounts against the node we migrated towards.
This seems wrong to me; all three sites should have the same
sementaics, furthermore we should accounts against where the page
really is, we already know where the task is.
So modify all three sites to always account; we did after all receive
the fault; and always account to where the page is after migration,
regardless of success.
They all still differ on when they clear the PTE/PMD; ideally that
would get sorted too.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-8-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
module->name is a fixed array, so we can check the empty contents
straightforwardly in module_slot_match().
Spotted by coverity CID 1056786.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
THP migrations are serialised by the page lock but on its own that does
not prevent THP splits. If the page is split during THP migration then
the pmd_same checks will prevent page table corruption but the unlock page
and other fix-ups potentially will cause corruption. This patch takes the
anon_vma lock to prevent parallel splits during migration.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-7-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The locking for migrating THP is unusual. While normal page migration
prevents parallel accesses using a migration PTE, THP migration relies on
a combination of the page_table_lock, the page lock and the existance of
the NUMA hinting PTE to guarantee safety but there is a bug in the scheme.
If a THP page is currently being migrated and another thread traps a
fault on the same page it checks if the page is misplaced. If it is not,
then pmd_numa is cleared. The problem is that it checks if the page is
misplaced without holding the page lock meaning that the racing thread
can be migrating the THP when the second thread clears the NUMA bit
and faults a stale page.
This patch checks if the page is potentially being migrated and stalls
using the lock_page if it is potentially being migrated before checking
if the page is misplaced or not.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-6-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fix a possible NULL access of indexp in fill_audio_out_name() called
from snd_hda_get_pin_label().
Spotted by coverity CID 402035.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The probe code of snd-usb-6fire driver overrides the devices[] pointer
wrongly without checking whether it's already occupied or not. This
would screw up the device disconnection later.
Spotted by coverity CID 141423.
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
If another task handled a hinting fault in parallel then do not double
account for it.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-5-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
