jump_lable patching is very expensive operation that involves pausing all
cpus. The patching of perf_sched_events jump_label is easily controllable
from userspace by unprivileged user.
When te user runs a loop like this:
"while true; do perf stat -e cycles true; done"
... the performance of my test application that just increments a counter
for one second drops by 4%.
This is on a 16 cpu box with my test application using only one of
them. An impact on a real server doing real work will be worse.
Performance of KVM PMU drops nearly 50% due to jump_lable for "perf
record" since KVM PMU implementation creates and destroys perf event
frequently.
This patch introduces a way to rate limit jump_label patching and uses
it to fix the above problem.
I believe that as jump_label use will spread the problem will become more
common and thus solving it in a generic code is appropriate. Also fixing
it in the perf code would result in moving jump_label accounting logic to
perf code with all the ifdefs in case of JUMP_LABEL=n kernel. With this
patch all details are nicely hidden inside jump_label code.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111127155909.GO2557@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch introduces x86 perf scheduler code helper functions. We
need this to later add more complex functionality to support
overlapping counter constraints (next patch).
The algorithm is modified so that the range of weight values is now
generated from the constraints. There shouldn't be other functional
changes.
With the helper functions the scheduler is controlled. There are
functions to initialize, traverse the event list, find unused counters
etc. The scheduler keeps its own state.
V3:
* Added macro for_each_set_bit_cont().
* Changed functions interfaces of perf_sched_find_counter() and
perf_sched_next_event() to use bool as return value.
* Added some comments to make code better understandable.
V4:
* Fix broken event assignment if weight of the first event is not
wmin (perf_sched_init()).
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1321616122-1533-2-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Gleb writes:
> Currently pmu is disabled and re-enabled on each timer interrupt even
> when no rotation or frequency adjustment is needed. On Intel CPU this
> results in two writes into PERF_GLOBAL_CTRL MSR per tick. On bare metal
> it does not cause significant slowdown, but when running perf in a virtual
> machine it leads to 20% slowdown on my machine.
Cure this by keeping a perf_event_context::nr_freq counter that counts the
number of active events that require frequency adjustments and use this in a
similar fashion to the already existing nr_events != nr_active test in
perf_rotate_context().
By being able to exclude both rotation and frequency adjustments a-priory for
the common case we can avoid the otherwise superfluous PMU disable.
Suggested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-515yhoatehd3gza7we9fapaa@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some are never used, some are set but never read, dev_hoq_count is
incremented and decremented, but never read.
Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We never walk ordered_cmd_list in the se_device, so remove all code related
to supporting it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
We already have a perfectly valid se_device pointer in the command, so
remove the mostly useless duplicates.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Convert to unsigned bit fields for active I/O shutdown fields.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch removes legacy usage of PYX_TRANSPORT_* return codes in a number
of locations and addresses cases where transport_generic_request_failure()
was returning the incorrect sense upon CHECK_CONDITION status after the
v3.1 converson to use errno return codes.
This includes the conversion of transport_generic_request_failure() to
process cmd->scsi_sense_reason and handle extra TCM_RESERVATION_CONFLICT
before calling transport_send_check_condition_and_sense() to queue up
response status. It also drops PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES legacy
usgae, and returns TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE w/ a response
for these cases.
transport_generic_allocate_tasks(), transport_generic_new_cmd(), backend
SCF_SCSI_DATA_SG_IO_CDB ->do_task(), and emulated ->execute_task() have
all been updated to set se_cmd->scsi_sense_reason and return errno codes
universally upon failure. This includes cmd->scsi_sense_reason assignment
in target_core_alua.c, target_core_pr.c and target_core_cdb.c emulation code.
Finally it updates fabric modules to remove the legacy usage, and for
TFO->new_cmd_map() callers forwards return values outside of fabric code.
iscsi-target has also been updated to remove a handful of special cases
related to the cleanup and signaling QUEUE_FULL handling w/ ft_write_pending()
(v2: Drop extra SCF_SCSI_CDB_EXCEPTION check during failure from
transport_generic_new_cmd, and re-add missing task->task_error_status
assignment in transport_complete_task)
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
intr_remapping: Fix section mismatch in ir_dev_scope_init()
intel-iommu: Fix section mismatch in dmar_parse_rmrr_atsr_dev()
x86, amd: Fix up numa_node information for AMD CPU family 15h model 0-0fh northbridge functions
x86, AMD: Correct align_va_addr documentation
x86/rtc, mrst: Don't register a platform RTC device for for Intel MID platforms
x86/mrst: Battery fixes
x86/paravirt: PTE updates in k(un)map_atomic need to be synchronous, regardless of lazy_mmu mode
x86: Fix "Acer Aspire 1" reboot hang
x86/mtrr: Resolve inconsistency with Intel processor manual
x86: Document rdmsr_safe restrictions
x86, microcode: Fix the failure path of microcode update driver init code
Add TAINT_FIRMWARE_WORKAROUND on MTRR fixup
x86/mpparse: Account for bus types other than ISA and PCI
x86, mrst: Change the pmic_gpio device type to IPC
mrst: Added some platform data for the SFI translations
x86,mrst: Power control commands update
x86/reboot: Blacklist Dell OptiPlex 990 known to require PCI reboot
x86, UV: Fix UV2 hub part number
x86: Add user_mode_vm check in stack_overflow_check
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix loss of notification with multi-event
perf, x86: Force IBS LVT offset assignment for family 10h
perf, x86: Disable PEBS on SandyBridge chips
trace_events_filter: Use rcu_assign_pointer() when setting ftrace_event_call->filter
perf session: Fix crash with invalid CPU list
perf python: Fix undefined symbol problem
perf/x86: Enable raw event access to Intel offcore events
perf: Don't use -ENOSPC for out of PMU resources
perf: Do not set task_ctx pointer in cpuctx if there are no events in the context
perf/x86: Fix PEBS instruction unwind
oprofile, x86: Fix crash when unloading module (nmi timer mode)
oprofile: Fix crash when unloading module (hr timer mode)
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched, x86: Avoid unnecessary overflow in sched_clock
sched: Fix buglet in return_cfs_rq_runtime()
sched: Avoid SMT siblings in select_idle_sibling() if possible
sched: Set the command name of the idle tasks in SMP kernels
sched, rt: Provide means of disabling cross-cpu bandwidth sharing
sched: Document wait_for_completion_*() return values
sched_fair: Fix a typo in the comment describing update_sd_lb_stats
sched: Add a comment to effective_load() since it's a pain
Add EthType 0x88b5.
This Ethertype value is available for public use for prototype and
vendor-specific protocol development,as defined in Amendment 802a
to IEEE Std 802.
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To reflect the fact that a refrence is not obtained to the
resulting neighbour entry.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Roland Dreier <roland@purestorage.com>
It's not always true that the device_node of regulator can be found
at dev->of_node at the time when of_get_regulator_init_data() is being
called, because in some cases the regulator nodes in device tree do
not have 'struct device' behind them until regulator_dev gets created
for it by core function regulator_register().
The patch adds device_node as a new parameter to
of_get_regulator_init_data(), so that caller can pass in the node of
regulator directly.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
More consistency cleanups. Drop the _OFF, separate and indent
CTRL/CAP/STATUS bit definitions. This helped find the previous
mis-use of bit 0 in the PASID capability register.
Reviewed-by: Joerg Roedel <joerg.roedel@amd.com>
Tested-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
If the kernel has requested control of the SHPC native hotplug
feature for a given root bridge, the acpiphp driver should not try
to handle that root bridge and it should leave it to shpchp.
Failing to do so causes problems to happen if shpchp is loaded
and unloaded before loading acpiphp (ACPI-based hotplug won't work
in that case anyway).
To address this issue make find_root_bridges() ignore PCI root
bridges with SHPC native hotplug enabled and make add_bridge()
return error code if SHPC native hotplug is enabled for the given
root bridge. This causes acpiphp to refuse to load if SHPC native
hotplug is enabled for all root bridges and to refuse binding to
the root bridges with SHPC native hotplug enabled.
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Right now we forcibly clear ASPM state on all devices if the BIOS indicates
that the feature isn't supported. Based on the Microsoft presentation
"PCI Express In Depth for Windows Vista and Beyond", I'm starting to think
that this may be an error. The implication is that unless the platform
grants full control via _OSC, Windows will not touch any PCIe features -
including ASPM. In that case clearing ASPM state would be an error unless
the platform has granted us that control.
This patch reworks the ASPM disabling code such that the actual clearing
of state is triggered by a successful handoff of PCIe control to the OS.
The general ASPM code undergoes some changes in order to ensure that the
ability to clear the bits isn't overridden by ASPM having already been
disabled. Further, this theoretically now allows for situations where
only a subset of PCIe roots hand over control, leaving the others in the
BIOS state.
It's difficult to know for sure that this is the right thing to do -
there's zero public documentation on the interaction between all of these
components. But enough vendors enable ASPM on platforms and then set this
bit that it seems likely that they're expecting the OS to leave them alone.
Measured to save around 5W on an idle Thinkpad X220.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This patch adds a per-pci-device subdirectory in sysfs called:
/sys/bus/pci/devices/<device>/msi_irqs
This sub-directory exports the set of msi vectors allocated by a given
pci device, by creating a numbered sub-directory for each vector beneath
msi_irqs. For each vector various attributes can be exported.
Currently the only attribute is called mode, which tracks the
operational mode of that vector (msi vs. msix)
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Allows devices to discover their own interrupt without having to remember
it themselves.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Sometimes the register map information may change in ways that drivers can
discover at runtime. For example, new revisions of a device may add new
registers. Support runtime discovery by drivers by allowing the register
cache to be reinitialised with a new function regmap_reinit_cache() which
discards the existing cache and creates a new one.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Currently, messages are just output on the detection of stack
overflow, which is not sufficient for systems that need a
high reliability. This is because in general the overflow may
corrupt data, and the additional corruption may occur due to
reading them unless systems stop.
This patch adds the sysctl parameter
kernel.panic_on_stackoverflow and causes a panic when detecting
the overflows of kernel, IRQ and exception stacks except user
stack according to the parameter. It is disabled by default.
Signed-off-by: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: http://lkml.kernel.org/r/20111129060836.11076.12323.stgit@ltc219.sdl.hitachi.co.jp
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When you do:
$ perf record -e cycles,cycles,cycles noploop 10
You expect about 10,000 samples for each event, i.e., 10s at
1000samples/sec. However, this is not what's happening. You
get much fewer samples, maybe 3700 samples/event:
$ perf report -D | tail -15
Aggregated stats:
TOTAL events: 10998
MMAP events: 66
COMM events: 2
SAMPLE events: 10930
cycles stats:
TOTAL events: 3644
SAMPLE events: 3644
cycles stats:
TOTAL events: 3642
SAMPLE events: 3642
cycles stats:
TOTAL events: 3644
SAMPLE events: 3644
On a Intel Nehalem or even AMD64, there are 4 counters capable
of measuring cycles, so there is plenty of space to measure those
events without multiplexing (even with the NMI watchdog active).
And even with multiplexing, we'd expect roughly the same number
of samples per event.
The root of the problem was that when the event that caused the buffer
to become full was not the first event passed on the cmdline, the user
notification would get lost. The notification was sent to the file
descriptor of the overflowed event but the perf tool was not polling
on it. The perf tool aggregates all samples into a single buffer,
i.e., the buffer of the first event. Consequently, it assumes
notifications for any event will come via that descriptor.
The seemingly straight forward solution of moving the waitq into the
ringbuffer object doesn't work because of life-time issues. One could
perf_event_set_output() on a fd that you're also blocking on and cause
the old rb object to be freed while its waitq would still be
referenced by the blocked thread -> FAIL.
Therefore link all events to the ringbuffer and broadcast the wakeup
from the ringbuffer object to all possible events that could be waited
upon. This is rather ugly, and we're open to better solutions but it
works for now.
Reported-by: Stephane Eranian <eranian@google.com>
Finished-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111126014731.GA7030@quad
Signed-off-by: Ingo Molnar <mingo@elte.hu>
like rt6_lookup, but allows caller to pass in flowi6 structure.
Will be used by the upcoming ipv6 netfilter reverse path filter
match.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This tries to do the same thing as fib_validate_source(), but differs
in several aspects.
The most important difference is that the reverse path filter built into
fib_validate_source uses the oif as iif when performing the reverse
lookup. We do not do this, as the oif is not yet known by the time the
PREROUTING hook is invoked.
We can't wait until FORWARD chain because by the time FORWARD is invoked
ipv4 forward path may have already sent icmp messages is response
to to-be-discarded-via-rpfilter packets.
To avoid the such an additional lookup in PREROUTING, Patrick McHardy
suggested to attach the path information directly in the match
(i.e., just do what the standard ipv4 path does a bit earlier in PREROUTING).
This works, but it also has a few caveats. Most importantly, when using
marks in PREROUTING to re-route traffic based on the nfmark, -m rpfilter
would have to be used after the nfmark has been set; otherwise the nfmark
would have no effect (because the route is already attached).
Another problem would be interaction with -j TPROXY, as this target sets an
nfmark and uses ACCEPT instead of continue, i.e. such a version of
-m rpfilter cannot be used for the initial to-be-intercepted packets.
In case in turns out that the oif is required, we can add Patricks
suggestion with a new match option (e.g. --rpf-use-oif) to keep ruleset
compatibility.
Another difference to current builtin ipv4 rpfilter is that packets subject to ipsec
transformation are not automatically excluded. If you want this, simply
combine -m rpfilter with the policy match.
Packets arriving on loopback interfaces always match.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We discovered that TCP stack could retransmit misaligned skbs if a
malicious peer acknowledged sub MSS frame. This currently can happen
only if output interface is non SG enabled : If SG is enabled, tcp
builds headless skbs (all payload is included in fragments), so the tcp
trimming process only removes parts of skb fragments, header stay
aligned.
Some arches cant handle misalignments, so force a head reallocation and
shrink headroom to MAX_TCP_HEADER.
Dont care about misaligments on x86 and PPC (or other arches setting
NET_IP_ALIGN to 0)
This patch introduces __pskb_copy() which can specify the headroom of
new head, and pskb_copy() becomes a wrapper on top of __pskb_copy()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's only used in net/ipv6/route.c and the NULL device check is
superfluous for all of the existing call sites.
Just expand the __ndisc_lookup_errno() call at each location.
Signed-off-by: David S. Miller <davem@davemloft.net>
Also prototype the "compat" functions so they can be referenced
from C code.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Open vSwitch is a multilayer Ethernet switch targeted at virtualized
environments. In addition to supporting a variety of features
expected in a traditional hardware switch, it enables fine-grained
programmatic extension and flow-based control of the network.
This control is useful in a wide variety of applications but is
particularly important in multi-server virtualization deployments,
which are often characterized by highly dynamic endpoints and the need
to maintain logical abstractions for multiple tenants.
The Open vSwitch datapath provides an in-kernel fast path for packet
forwarding. It is complemented by a userspace daemon, ovs-vswitchd,
which is able to accept configuration from a variety of sources and
translate it into packet processing rules.
See http://openvswitch.org for more information and userspace
utilities.
Signed-off-by: Jesse Gross <jesse@nicira.com>
While parsing through IPv6 extension headers, fragment headers are
skipped making them invisible to the caller. This reports the
fragment offset of the last header in order to make it possible to
determine whether the packet is fragmented and, if so whether it is
a first or last fragment.
Signed-off-by: Jesse Gross <jesse@nicira.com>
This adds rcu_dereference_genl and genl_dereference, which are genl
variants of the RTNL functions to enforce proper locking with lockdep
and sparse.
Signed-off-by: Jesse Gross <jesse@nicira.com>
Open vSwitch uses genl_mutex locking to protect datapath
data-structures like flow-table, flow-actions. Following patch adds
lockdep_genl_is_held() which is used for rcu annotation to prove
locking.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Open vSwitch uses Generic Netlink interface for communication
between userspace and kernel module. genl_notify() is used
for sending notification back to userspace.
genl_notify() is analogous to rtnl_notify() but uses genl_sock
instead of rtnl.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Move vpif related definitions for capture and display drivers
from dm646x platform header file to vpif_types.h inside
the driver as these definitions are related to driver code
rather than the platform or board.
This enables reusing this IP across platforms.
Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
vmwgfx: integer overflow in vmw_kms_update_layout_ioctl()
drm/radeon/kms: fix 2D tiling CS support on EG/CM
drm/radeon/kms: fix scanout of 2D tiled buffers on EG/CM
drm: Fix lack of CRTC disable for drm_crtc_helper_set_config(.fb=NULL)
drm/radeon/kms: add some new pci ids
drm/radeon/kms: Skip ACPI call to ATIF when possible
drm/radeon/kms: Hide debugging message
drm/radeon/kms: add some loop timeouts in pageflip code
drm/nv50/disp: silence compiler warning
drm/nouveau: fix oopses caused by clear being called on unpopulated ttms
drm/nouveau: Keep RAMIN heap within the channel.
drm/nvd0/disp: fix sor dpms typo, preventing dpms on in some situations
drm/nvc0/gr: fix TP init for transform feedback offset queries
drm/nouveau: add dumb ioctl support
