Commit Graph

76304 Commits

Author SHA1 Message Date
Eddie Huang
1c5841e832 tty: serial: 8250: export early_serial8250_setup function
8250-like uart driver may call early_serial8250_setup to
reuse 8250_early.c character output function.

Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 19:00:05 +02:00
Geert Uytterhoeven
34ef33f7da usb: phy: Remove the phy-rcar-gen2-usb driver
The phy-rcar-gen2-usb driver, which supports legacy platform data only,
is no longer used since commit a483dcbfa2 ("ARM: shmobile: lager:
Remove legacy board support").

This driver was superseded by the DT-only phy-rcar-gen2 driver, which
was introduced in commit 1233f59f74 ("phy: Renesas R-Car Gen2 PHY
driver").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 15:44:10 +02:00
Jason Low
920ce39f6c sched, timer: Fix documentation for 'struct thread_group_cputimer'
Fix the docbook build bug reported by Fengguang Wu.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jason Low <jason.low2@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman.Long@hp.com
Cc: aswin@hp.com
Cc: bp@alien8.de
Cc: dave@stgolabs.net
Cc: fweisbec@gmail.com
Cc: mgorman@suse.de
Cc: oleg@redhat.com
Cc: paulmck@linux.vnet.ibm.com
Cc: preeti@linux.vnet.ibm.com
Cc: riel@redhat.com
Cc: rostedt@goodmis.org
Cc: scott.norton@hp.com
Cc: torvalds@linux-foundation.org
Cc: umgwanakikbuti@gmail.com
Link: http://lkml.kernel.org/r/1431120710.5136.12.camel@j-VirtualBox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-10 12:45:27 +02:00
Tom Herbert
78f5b89919 mpls: Change reserved label names to be consistent with netbsd
Since these are now visible to userspace it is nice to be consistent
with BSD (sys/netmpls/mpls.h in netBSD).

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:29:50 -04:00
Nicolas Dichtel
59324cf35a netlink: allow to listen "all" netns
More accurately, listen all netns that have a nsid assigned into the netns
where the netlink socket is opened.
For this purpose, a netlink socket option is added:
NETLINK_LISTEN_ALL_NSID. When this option is set on a netlink socket, this
socket will receive netlink notifications from all netns that have a nsid
assigned into the netns where the socket has been opened. The nsid is sent
to userland via an anscillary data.

With this patch, a daemon needs only one socket to listen many netns. This
is useful when the number of netns is high.

Because 0 is a valid value for a nsid, the field nsid_is_set indicates if
the field nsid is valid or not. skb->cb is initialized to 0 on skb
allocation, thus we are sure that we will never send a nsid 0 by error to
the userland.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:31 -04:00
Nicolas Dichtel
7a0877d4b4 netns: rename peernet2id() to peernet2id_alloc()
In a following commit, a new function will be introduced to only lookup for
a nsid (no allocation if the nsid doesn't exist). To avoid confusion, the
existing function is renamed.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:15:30 -04:00
David S. Miller
43996fdd9b Merge tag 'linux-can-next-for-4.2-20150506' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next
Marc Kleine-Budde says:

====================
pull-request: can-next 2015-05-06

this is a pull request of a seven patches for net-next/master.

Andreas Gröger contributes two patches for the janz-ican3 driver. In
the first patch, the documentation for already existing sysfs entries
is added, the second patch adds support for another module/firmware
variant. A patch by Shawn Landden makes the padding in the struct
can_frame explicit. The next 4 patches target the flexcan driver, the
first one is by David Jander adding some documentation, the reaming
three by me add more documentation and two small code cleanups.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 22:12:17 -04:00
Linus Torvalds
9d88f22a81 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "Two patches from the irq departement:

   - a simple fix to make dummy_irq_chip usable for wakeup scenarios

   - removal of the gic arch_extn hackery.  Now that all users are
     converted we really want to get rid of the interface so people wont
     come up with new use cases"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: gic: Drop support for gic_arch_extn
  genirq: Set IRQCHIP_SKIP_SET_WAKE flag for dummy_irq_chip
2015-05-09 14:59:05 -07:00
Daniel Borkmann
ac67eb2c53 seccomp, filter: add and use bpf_prog_create_from_user from seccomp
Seccomp has always been a special candidate when it comes to preparation
of its filters in seccomp_prepare_filter(). Due to the extra checks and
filter rewrite it partially duplicates code and has BPF internals exposed.

This patch adds a generic API inside the BPF code code that seccomp can use
and thus keep it's filter preparation code minimal and better maintainable.
The other side-effect is that now classic JITs can add seccomp support as
well by only providing a BPF_LDX | BPF_W | BPF_ABS translation.

Tested with seccomp and BPF test suites.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
Nicolas Schichan
d9e12f42e5 seccomp: simplify seccomp_prepare_filter and reuse bpf_prepare_filter
Remove the calls to bpf_check_classic(), bpf_convert_filter() and
bpf_migrate_runtime() and let bpf_prepare_filter() take care of that
instead.

seccomp_check_filter() is passed to bpf_prepare_filter() so that it
gets called from there, after bpf_check_classic().

We can now remove exposure of two internal classic BPF functions
previously used by seccomp. The export of bpf_check_classic() symbol,
previously known as sk_chk_filter(), was there since pre git times,
and no in-tree module was using it, therefore remove it.

Joint work with Daniel Borkmann.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
Nicolas Schichan
4ae92bc77a net: filter: add a callback to allow classic post-verifier transformations
This is in preparation for use by the seccomp code, the rationale is
not to duplicate additional code within the seccomp layer, but instead,
have it abstracted and hidden within the classic BPF API.

As an interim step, this now also makes bpf_prepare_filter() visible
(not as exported symbol though), so that seccomp can reuse that code
path instead of reimplementing it.

Joint work with Daniel Borkmann.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:35:05 -04:00
David S. Miller
0e00a0f73f Merge tag 'mac80211-next-for-davem-2015-05-06' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next
Johannes Berg says:

====================
Lots of updates for net-next for this cycle. As usual, we have
a lot of small fixes and cleanups, the bigger items are:
 * proper mac80211 rate control locking, to fix some random crashes
   (this required changing other locking as well)
 * mac80211 "fast-xmit", a mechanism to reduce, in most cases, the
   amount of code we execute while going from ndo_start_xmit() to
   the driver
 * this also clears the way for properly supporting S/G and checksum
   and segmentation offloads
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 17:27:25 -04:00
Eric Dumazet
e520af48c7 tcp: add TCPWinProbe and TCPKeepAlive SNMP counters
Diagnosing problems related to Window Probes has been hard because
we lack a counter.

TCPWinProbe counts the number of ACK packets a sender has to send
at regular intervals to make sure a reverse ACK packet opening back
a window had not been lost.

TCPKeepAlive counts the number of ACK packets sent to keep TCP
flows alive (SO_KEEPALIVE)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 16:42:32 -04:00
Eric Dumazet
21c8fe9915 tcp: adjust window probe timers to safer values
With the advent of small rto timers in datacenter TCP,
(ip route ... rto_min x), the following can happen :

1) Qdisc is full, transmit fails.

   TCP sets a timer based on icsk_rto to retry the transmit, without
   exponential backoff.
   With low icsk_rto, and lot of sockets, all cpus are servicing timer
   interrupts like crazy.
   Intent of the code was to retry with a timer between 200 (TCP_RTO_MIN)
   and 500ms (TCP_RESOURCE_PROBE_INTERVAL)

2) Receivers can send zero windows if they don't drain their receive queue.

   TCP sends zero window probes, based on icsk_rto current value, with
   exponential backoff.
   With /proc/sys/net/ipv4/tcp_retries2 being 15 (or even smaller in
   some cases), sender can abort in less than one or two minutes !
   If receiver stops the sender, it obviously doesn't care of very tight
   rto. Probability of dropping the ACK reopening the window is not
   worth the risk.

Lets change the base timer to be at least 200ms (TCP_RTO_MIN) for these
events (but not normal RTO based retransmits)

A followup patch adds a new SNMP counter, as it would have helped a lot
diagnosing this issue.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09 16:42:32 -04:00
Greg Kroah-Hartman
5ccca15567 Merge tag 'iio-for-v4.2a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next
Jonathan writes:

First round of new drivers, functionality and cleanups for the 4.2 cycle

New drivers / device support
* st sensors driver, lsm303dlh magnetometer support.
* ltr501 - support ltr301 and ltr559 chips.

New functionality
* IIO_CHAN_INFO_CALIBEMISSIVITY for thermopile sensors.
* kxcjk1013 - make driver operational with external trigger.
* Add iio targets to the tools Makefile.

Cleanups
* st sensors - more helpful error message if device id wrong or irq request
  fails, explicitly make the Block Data Update optional rather
  than relying on writes to address 0 not doing anything, make interrupt
  support optional (Not always wired, and not all devices actually have
  an interrupt line.)
* kxcjk-1013 white space additions for readability, add the KXCJ9000 ACPI
  id as seen in the wild.
* sx9500 - GPIO reset support, refactor the GPIO interrupt code, add power
  management, optimize power usage by powering down when possible, rename
  the gpio interrupt pin to be more useful, trivial return path simplification,
  trivial formatting fixes.
* isl29018 -  move towards ABI compliance with a view to moving this driver
  out of staging, add some brackets to ensure code works as expected.  Note
  there is no actual bug as the condition being tested is always true
  (with current devices).
* ltr501 - add regmap support to get caching etc for later patches,
  fix a parameter sanity check that always fails (bug introduced
  earlier in this series), ACPI enumeration support,
  interrupt rate control support, interrupt support in general and
  integration time control support, code alignment cleanups.
* mma9553 - a number of little cleanups following a review from Hartmut
  after I'd already applied the original driver patch.
* tmp006 - prefix some defines with TMP006 for consistency.
* tsl4531 - cleanup some wrong prefixes, presumably from copy and paste.
* mlx90614 - check for errors in read values, add power management,
  add emissivity setting, add device tree binding documentation,
  fix a duplicate const warning.
* ti_am335x_adc - refactor the DT parsing into a separate function.
2015-05-09 18:15:50 +02:00
Peter Ujfalusi
56f13c0d95 dmaengine: of_dma: Support for DMA routers
DMA routers are transparent devices used to mux DMA requests from
peripherals to DMA controllers. They are used when the SoC integrates more
devices with DMA requests then their controller can handle.
DRA7x is one example of such SoC, where the sDMA can hanlde 128 DMA request
lines, but in SoC level it has 205 DMA requests.

The of_dma_router will be registered as of_dma_controller with special
xlate function and additional parameters. The driver for the router is
responsible to craft the dma_spec (in the of_dma_route_allocate callback)
which can be used to requests a DMA channel from the real DMA controller.
This way the router can be transparent for the system while remaining generic
enough to be used in different environments.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-09 17:11:25 +05:30
Linus Torvalds
1daac193f2 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
 "A collection of fixes since the merge window;

   - fix for a double elevator module release, from Chao Yu.  Ancient bug.

   - the splice() MORE flag fix from Christophe Leroy.

   - a fix for NVMe, fixing a patch that went in in the merge window.
     From Keith.

   - two fixes for blk-mq CPU hotplug handling, from Ming Lei.

   - bdi vs blockdev lifetime fix from Neil Brown, fixing and oops in md.

   - two blk-mq fixes from Shaohua, fixing a race on queue stop and a
     bad merge issue with FUA writes.

   - division-by-zero fix for writeback from Tejun.

   - a block bounce page accounting fix, making sure we inc/dec after
     bouncing so that pre/post IO pages match up.  From Wang YanQing"

* 'for-linus' of git://git.kernel.dk/linux-block:
  splice: sendfile() at once fails for big files
  blk-mq: don't lose requests if a stopped queue restarts
  blk-mq: fix FUA request hang
  block: destroy bdi before blockdev is unregistered.
  block:bounce: fix call inc_|dec_zone_page_state on different pages confuse value of NR_BOUNCE
  elevator: fix double release of elevator module
  writeback: use |1 instead of +1 to protect against div by zero
  blk-mq: fix CPU hotplug handling
  blk-mq: fix race between timeout and CPU hotplug
  NVMe: Fix VPD B0 max sectors translation
2015-05-08 19:49:35 -07:00
Linus Torvalds
26b293e854 Merge tag 'trace-fixes-v4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
 "The newly added ftrace_print_array_seq() function had a bug in it.
  Luckily, the only user of it didn't make the 4.1 merge window.

  But the helper function should be fixed before 4.2 when the users
  start coming in"

* tag 'trace-fixes-v4.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Make ftrace_print_array_seq compute buf_len
2015-05-08 18:22:05 -07:00
Michael Turquette
8157356015 Merge branch 'clk-fixes' into clk-next 2015-05-08 11:57:23 -07:00
Sebastian Hesselbarth
0cd3be6e9a clk: si5351: Do not pass struct clk in platform_data
When registering clk-si5351 by platform_data, we should not pass struct clk
for the reference clocks. Drop struct clk from platform_data and rework the
driver to use devm_clk_get of named clock references.

While at it, check for at least one valid input clock and properly prepare/
enable valid reference clocks.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Reported-by: Michael Welling <mwelling@ieee.org>
Reported-by: Jean-Francois Moine <moinejf@free.fr>
Reported-by: Russell King <rmk+linux@arm.linux.org.uk>
Tested-by: Michael Welling <mwelling@ieee.org>
Tested-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-05-08 11:22:30 -07:00
Daniel Vetter
ac6f2e29bb drm/edid: Kerneldoc for newly added edid_corrupt
Also treat it as a proper boolean.

Cc: Todd Previte <tprevite@gmail.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-05-08 17:26:01 +02:00
Daniel Stone
8fb6e7a579 drm: Introduce blob_lock
Create a new global blob_lock mutex, which protects the blob property
list from insertion and/or deletion.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-08 13:30:01 +02:00
Todd Previte
6ba2bd3da7 drm: Add edid_corrupt flag for Displayport Link CTS 4.2.2.6
Displayport compliance test 4.2.2.6 requires that a source device be capable of
detecting a corrupt EDID. The test specification states that the sink device
sets up the EDID with an invalid checksum. To do this, the sink sets up an
invalid EDID header, expecting the source device to generate the checksum and
compare it to the value stored in the last byte of the block data.

Unfortunately, the DRM EDID reading and parsing functions are actually too good
in this case; the header is fixed before the checksum is computed and thus the
test never sees the invalid checksum. This results in a failure to pass the
compliance test.

To correct this issue, when the EDID code detects that the header is invalid,
a flag is set to indicate that the EDID is corrupted. In this case, it sets
edid_corrupt flag and continues with its fix-up code. This flag is also set in
the case of a more seriously damaged header (fixup score less than the
threshold). For consistency, the edid_corrupt flag is also set when the
checksum is invalid as well.

V2:
- Removed the static bool global
- Added a bool to the drm_connector struct to reaplce the static one for
  holding the status of raw edid header corruption detection
- Modified the function signature of the is_valid function to take an
  additional parameter to store the corruption detected value
- Fixed the other callers of the above is_valid function
V3:
- Updated the commit message to be more clear about what and why this
  patch does what it does.
- Added comment in code to clarify the operations there
- Removed compliance variable and check_link_status update; those
  have been moved to a later patch
- Removed variable assignment from the bottom of the test handler
V4:
- Removed i915 tag from subject line as the patch is not i915-specific
V5:
- Moved code causing a compilation error to this patch where the variable
  is actually declared
- Maintained blank lines / spacing so as to not contaminate the patch
V6:
- Removed extra debug messages
- Added documentation to for the added parameter on drm_edid_block_valid
- Fixed more whitespace issues in check_link_status
- Added a clear of the header_corrupt flag to the end of the test handler
  in intel_dp.c
- Changed the usage of the new function prototype in several places to use
  NULL where it is not needed by compliance testing
V7:
- Updated to account for long_pulse flag propagation
V8:
- Removed clearing of header_corrupt flag from the test handler in intel_dp.c
- Added clearing of header_corrupt flag in the drm_edid_block_valid function
V9:
- Renamed header_corrupt flag to edid_corrupt to more accurately reflect its
  value and purpose
- Updated commit message
V10:
- Updated for versioning and patch swizzle
- Revised the title to more accurately reflect the nature and contents of
  the patch
- Fixed formatting/whitespace problems
- Added set flag when computed checksum is invalid

Signed-off-by: Todd Previte <tprevite@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-05-08 13:03:46 +02:00
Dave Airlie
e1dee1973c Merge tag 'drm-intel-next-2015-04-23-fixed' of git://anongit.freedesktop.org/drm-intel into drm-next
drm-intel-next-2015-04-23:
- dither support for ns2501 dvo (Thomas Richter)
- some polish for the gtt code and fixes to finally enable the cmd parser on hsw
- first pile of bxt stage 1 enabling (too many different people to list ...)
- more psr fixes from Rodrigo
- skl rotation support from Chandra
- more atomic work from Ander and Matt
- pile of cleanups and micro-ops for execlist from Chris
drm-intel-next-2015-04-10:
- cdclk handling cleanup and fixes from Ville
- more prep patches for olr removal from John Harrison
- gmbus pin naming rework from Jani (prep for bxt)
- remove ->new_config from Ander (more atomic conversion work)
- rps (boost) tuning and unification with byt/bsw from Chris
- cmd parser batch bool tuning from Chris
- gen8 dynamic pte allocation (Michel Thierry, based on work from Ben Widawsky)
- execlist tuning (not yet all of it) from Chris
- add drm_plane_from_index (Chandra)
- various small things all over

* tag 'drm-intel-next-2015-04-23-fixed' of git://anongit.freedesktop.org/drm-intel: (204 commits)
  drm/i915/gtt: Allocate va range only if vma is not bound
  drm/i915: Enable cmd parser to do secure batch promotion for aliasing ppgtt
  drm/i915: fix intel_prepare_ddi
  drm/i915: factor out ddi_get_encoder_port
  drm/i915/hdmi: check port in ibx_infoframe_enabled
  drm/i915/hdmi: fix vlv infoframe port check
  drm/i915: Silence compiler warning in dvo
  drm/i915: Update DRIVER_DATE to 20150423
  drm/i915: Enable dithering on NatSemi DVO2501 for Fujitsu S6010
  rm/i915: Move i915_get_ggtt_vma_pages into ggtt_bind_vma
  drm/i915: Don't try to outsmart gcc in i915_gem_gtt.c
  drm/i915: Unduplicate i915_ggtt_unbind/bind_vma
  drm/i915: Move ppgtt_bind/unbind around
  drm/i915: move i915_gem_restore_gtt_mappings around
  drm/i915: Fix up the vma aliasing ppgtt binding
  drm/i915: Remove misleading comment around bind_to_vm
  drm/i915: Don't use atomics for pg_dirty_rings
  drm/i915: Don't look at pg_dirty_rings for aliasing ppgtt
  drm/i915/skl: Support Y tiling in MMIO flips
  drm/i915: Fixup kerneldoc for struct intel_context
  ...

Conflicts:
	drivers/gpu/drm/i915/i915_drv.c
2015-05-08 20:51:06 +10:00
Peter Zijlstra (Intel)
2aa79af642 locking/qspinlock: Revert to test-and-set on hypervisors
When we detect a hypervisor (!paravirt, see qspinlock paravirt support
patches), revert to a simple test-and-set lock to avoid the horrors
of queue preemption.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-8-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:58 +02:00
Peter Zijlstra (Intel)
69f9cae909 locking/qspinlock: Optimize for smaller NR_CPUS
When we allow for a max NR_CPUS < 2^14 we can optimize the pending
wait-acquire and the xchg_tail() operations.

By growing the pending bit to a byte, we reduce the tail to 16bit.
This means we can use xchg16 for the tail part and do away with all
the repeated compxchg() operations.

This in turn allows us to unconditionally acquire; the locked state
as observed by the wait loops cannot change. And because both locked
and pending are now a full byte we can use simple stores for the
state transition, obviating one atomic operation entirely.

This optimization is needed to make the qspinlock achieve performance
parity with ticket spinlock at light load.

All this is horribly broken on Alpha pre EV56 (and any other arch that
cannot do single-copy atomic byte stores).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-6-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:48 +02:00
Waiman Long
6403bd7d0e locking/qspinlock: Extract out code snippets for the next patch
This is a preparatory patch that extracts out the following 2 code
snippets to prepare for the next performance optimization patch.

 1) the logic for the exchange of new and previous tail code words
    into a new xchg_tail() function.
 2) the logic for clearing the pending bit and setting the locked bit
    into a new clear_pending_set_locked() function.

This patch also simplifies the trylock operation before queuing by
calling queued_spin_trylock() directly.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-5-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:41 +02:00
Peter Zijlstra (Intel)
c1fb159db9 locking/qspinlock: Add pending bit
Because the qspinlock needs to touch a second cacheline (the per-cpu
mcs_nodes[]); add a pending bit and allow a single in-word spinner
before we punt to the second cacheline.

It is possible so observe the pending bit without the locked bit when
the last owner has just released but the pending owner has not yet
taken ownership.

In this case we would normally queue -- because the pending bit is
already taken. However, in this case the pending bit is guaranteed
to be released 'soon', therefore wait for it and avoid queueing.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-4-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:32 +02:00
Waiman Long
a33fda35e3 locking/qspinlock: Introduce a simple generic 4-byte queued spinlock
This patch introduces a new generic queued spinlock implementation that
can serve as an alternative to the default ticket spinlock. Compared
with the ticket spinlock, this queued spinlock should be almost as fair
as the ticket spinlock. It has about the same speed in single-thread
and it can be much faster in high contention situations especially when
the spinlock is embedded within the data structure to be protected.

Only in light to moderate contention where the average queue depth
is around 1-3 will this queued spinlock be potentially a bit slower
due to the higher slowpath overhead.

This queued spinlock is especially suit to NUMA machines with a large
number of cores as the chance of spinlock contention is much higher
in those machines. The cost of contention is also higher because of
slower inter-node memory traffic.

Due to the fact that spinlocks are acquired with preemption disabled,
the process will not be migrated to another CPU while it is trying
to get a spinlock. Ignoring interrupt handling, a CPU can only be
contending in one spinlock at any one time. Counting soft IRQ, hard
IRQ and NMI, a CPU can only have a maximum of 4 concurrent lock waiting
activities.  By allocating a set of per-cpu queue nodes and used them
to form a waiting queue, we can encode the queue node address into a
much smaller 24-bit size (including CPU number and queue node index)
leaving one byte for the lock.

Please note that the queue node is only needed when waiting for the
lock. Once the lock is acquired, the queue node can be released to
be used later.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-2-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:36:25 +02:00
Preeti U Murthy
663fdcbee0 kernel: Replace reference to ASSIGN_ONCE() with WRITE_ONCE() in comment
Looks like commit :

 43239cbe79 ("kernel: Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)")

left behind a reference to ASSIGN_ONCE(). Update this to WRITE_ONCE().

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: borntraeger@de.ibm.com
Cc: dave@stgolabs.net
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/20150430115721.22278.94082.stgit@preeti.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:28:53 +02:00
Waiman Long
59aabfc7e9 locking/rwsem: Reduce spinlock contention in wakeup after up_read()/up_write()
In up_write()/up_read(), rwsem_wake() will be called whenever it
detects that some writers/readers are waiting. The rwsem_wake()
function will take the wait_lock and call __rwsem_do_wake() to do the
real wakeup.  For a heavily contended rwsem, doing a spin_lock() on
wait_lock will cause further contention on the heavily contended rwsem
cacheline resulting in delay in the completion of the up_read/up_write
operations.

This patch makes the wait_lock taking and the call to __rwsem_do_wake()
optional if at least one spinning writer is present. The spinning
writer will be able to take the rwsem and call rwsem_wake() later
when it calls up_write(). With the presence of a spinning writer,
rwsem_wake() will now try to acquire the lock using trylock. If that
fails, it will just quit.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Jason Low <jason.low2@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430428337-16802-2-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:27:59 +02:00
Peter Zijlstra
ff303e66c2 perf: Fix software migrate events
Stephane asked about PERF_COUNT_SW_CPU_MIGRATIONS and I realized it
was borken:

 > The problem is that the task isn't actually scheduled while its being
 > migrated (obviously), and if its not scheduled, the counters aren't
 > scheduled either, so there's no observing of the fact.
 >
 > A further problem with migrations is that many migrations happen from
 > softirq context, which is nested inside the 'random' task context of
 > whoemever happens to run at that time, similarly for the wakeup
 > migrations triggered from (soft)irq context. All those end up being
 > accounted in the task that's currently running, eg. your 'ls'.

The below cures this by marking a task as migrated and accounting it
on the subsequent sched_in().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:25:38 +02:00
Peter Zijlstra
7675104990 sched: Implement lockless wake-queues
This is useful for locking primitives that can effect multiple
wakeups per operation and want to avoid lock internal lock contention
by delaying the wakeups until we've released the lock internal locks.

Alternatively it can be used to avoid issuing multiple wakeups, and
thus save a few cycles, in packet processing. Queue all target tasks
and wakeup once you've processed all packets. That way you avoid
waking the target task multiple times if there were multiple packets
for the same task.

Properties of a wake_q are:
- Lockless, as queue head must reside on the stack.
- Being a queue, maintains wakeup order passed by the callers. This can
  be important for otherwise, in scenarios where highly contended locks
  could affect any reliance on lock fairness.
- A queued task cannot be added again until it is woken up.

This patch adds the needed infrastructure into the scheduler code
and uses the new wake_list to delay the futex wakeups until
after we've released the hash bucket locks.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[tweaks, adjustments, comments, etc.]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Mason <clm@fb.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: George Spelvin <linux@horizon.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1430494072-30283-2-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:20:45 +02:00
Jason Low
7110744516 sched, timer: Use the atomic task_cputime in thread_group_cputimer
Recent optimizations were made to thread_group_cputimer to improve its
scalability by keeping track of cputime stats without a lock. However,
the values were open coded to the structure, causing them to be at
a different abstraction level from the regular task_cputime structure.
Furthermore, any subsequent similar optimizations would not be able to
share the new code, since they are specific to thread_group_cputimer.

This patch adds the new task_cputime_atomic data structure (introduced in
the previous patch in the series) to thread_group_cputimer for keeping
track of the cputime atomically, which also helps generalize the code.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1430251224-5764-6-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:17:46 +02:00
Jason Low
971e8a9854 sched, timer: Provide an atomic 'struct task_cputime' data structure
This patch adds an atomic variant of the 'struct task_cputime' data structure,
which can be used to store and update task_cputime statistics without
needing to do locking.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1430251224-5764-5-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:17:45 +02:00
Jason Low
1018016c70 sched, timer: Replace spinlocks with atomics in thread_group_cputimer(), to improve scalability
While running a database workload, we found a scalability issue with itimers.

Much of the problem was caused by the thread_group_cputimer spinlock.
Each time we account for group system/user time, we need to obtain a
thread_group_cputimer's spinlock to update the timers. On larger systems
(such as a 16 socket machine), this caused more than 30% of total time
spent trying to obtain this kernel lock to update these group timer stats.

This patch converts the timers to 64-bit atomic variables and use
atomic add to update them without a lock. With this patch, the percent
of total time spent updating thread group cputimer timers was reduced
from 30% down to less than 1%.

Note: On 32-bit systems using the generic 64-bit atomics, this causes
sample_group_cputimer() to take locks 3 times instead of just 1 time.
However, we tested this patch on a 32-bit system ARM system using the
generic atomics and did not find the overhead to be much of an issue.
An explanation for why this isn't an issue is that 32-bit systems usually
have small numbers of CPUs, and cacheline contention from extra spinlocks
called periodically is not really apparent on smaller systems.

Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1430251224-5764-4-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:15:31 +02:00
Jason Low
316c1608d1 sched, timer: Convert usages of ACCESS_ONCE() in the scheduler to READ_ONCE()/WRITE_ONCE()
ACCESS_ONCE doesn't work reliably on non-scalar types. This patch removes
the rest of the existing usages of ACCESS_ONCE() in the scheduler, and use
the new READ_ONCE() and WRITE_ONCE() APIs as appropriate.

Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Waiman Long <Waiman.Long@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1430251224-5764-2-git-send-email-jason.low2@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:11:32 +02:00
Palmer Dabbelt
e7cc417311 signals, ptrace, sched: Fix a misaligned load inside ptrace_attach()
The misaligned load exception arises when running ptrace_attach() on
the RISC-V (which hasn't been upstreamed yet).  The problem is that
wait_on_bit() takes a void* but then proceeds to call test_bit(),
which takes a long*.  This allows an int-aligned pointer to be passed
to test_bit(), which promptly fails.  This will manifest on any other
asm-generic port where unaligned loads trap, where sizeof(long) >
sizeof(int), and where task_struct.jobctl ends up not being
long-aligned.

This patch changes task_struct.jobctl to be a long, which ensures it
has the correct alignment.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bobby.prani@gmail.com
Cc: oleg@redhat.com
Cc: paulmck@linux.vnet.ibm.com
Cc: richard@nod.at
Cc: vdavydov@parallels.com
Link: http://lkml.kernel.org/r/1430453997-32459-2-git-send-email-palmer@dabbelt.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:06:57 +02:00
Palmer Dabbelt
7e60598785 sched/wait: Change wait_on_bit*() to take an unsigned long *, not a void *
The implementations of wait_on_bit*() will only work with long-aligned
memory on systems that don't support misaligned loads and stores.

This patch changes the function prototypes to ensure that the compiler
will enforce alignment.

Running

  make defconfig
  make KFLAGS="-Werror"

seems to indicate that, as of c56fb6564dcd ("Fix a misaligned load
inside ptrace_attach()"), there are now no users of non-long-aligned
calls to wait_on_bit*().  I additionally tried a few "make randconfig"
attempts, none of which failed to compile for this reason.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bobby.prani@gmail.com
Cc: oleg@redhat.com
Cc: paulmck@linux.vnet.ibm.com
Cc: richard@nod.at
Cc: vdavydov@parallels.com
Link: http://lkml.kernel.org/r/1430453997-32459-3-git-send-email-palmer@dabbelt.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:05:41 +02:00
Palmer Dabbelt
b76808e680 signals, sched: Change all uses of JOBCTL_* from 'int' to 'long'
c56fb6564dcd ("Fix a misaligned load inside ptrace_attach()") makes
jobctl an "unsigned long".  It makes sense to have the masks applied
to it match that type.  This is currently just a cosmetic change, but
it will prevent the mask from being unexpectedly truncated if we ever
end up with masks with more bits.

One instance of "signr" is an int, but I left this alone because the
mask ensures that it will never overflow.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bobby.prani@gmail.com
Cc: oleg@redhat.com
Cc: paulmck@linux.vnet.ibm.com
Cc: richard@nod.at
Cc: vdavydov@parallels.com
Link: http://lkml.kernel.org/r/1430453997-32459-4-git-send-email-palmer@dabbelt.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:04:36 +02:00
Peter Zijlstra
3289bdb429 sched: Move the loadavg code to a more obvious location
I could not find the loadavg code.. turns out it was hidden in a file
called proc.c. It further got mingled up with the cruft per rq load
indexes (which we really want to get rid of).

Move the per rq load indexes into the fair.c load-balance code (that's
the only thing that uses them) and rename proc.c to loadavg.c so we
can find it again.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
[ Did minor cleanups to the code. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 12:04:12 +02:00
Thomas Gleixner
0782e63bc6 sched: Handle priority boosted tasks proper in setscheduler()
Ronny reported that the following scenario is not handled correctly:

	T1 (prio = 10)
	   lock(rtmutex);

	T2 (prio = 20)
	   lock(rtmutex)
	      boost T1

	T1 (prio = 20)
	   sys_set_scheduler(prio = 30)
	   T1 prio = 30
	   ....
	   sys_set_scheduler(prio = 10)
	   T1 prio = 30

The last step is wrong as T1 should now be back at prio 20.

Commit c365c292d0 ("sched: Consider pi boosting in setscheduler()")
only handles the case where a boosted tasks tries to lower its
priority.

Fix it by taking the new effective priority into account for the
decision whether a change of the priority is required.

Reported-by: Ronny Meeus <ronny.meeus@gmail.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Fixes: c365c292d0 ("sched: Consider pi boosting in setscheduler()")
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1505051806060.4225@nanos
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08 11:53:55 +02:00
Geert Uytterhoeven
385f83f85c dmaengine: Remove Renesas Audio DMAC peri peri platform data
Commit 3cd44dcd35 ("dmaengine: remove Renesas Audio DMAC peri peri")
forgot to remove the header file with the platform data definitions.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-05-08 14:37:52 +05:30
Jaegeuk Kim
5d79988139 f2fs: export more enums for tracepoint
This patch exports newly added enums to userspace.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-05-07 11:38:31 -07:00
Bjorn Helgaas
c6201cd851 PCI/MSI: Remove unused pci_msi_off()
pci_msi_off() is unused, so remove it.

Removes the exported symbol pci_msi_off().

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-05-07 09:52:22 -05:00
Linus Torvalds
8cb7c15b32 Merge tag 'for-linus' of git://github.com/dledford/linux
Pull infiniband updates from Doug Ledford:
 "Minor updates for 4.1-rc

  Most of the changes are fairly small and well confined.  The iWARP
  address reporting changes are the only ones that are a medium size.  I
  had these queued up prior to rc1, but due to the shuffle in
  maintainers, they did not get submitted when I expected.  My apologies
  for that.  I feel comfortable with them however due to the testing
  they've received, so I left them in this submission"

* tag 'for-linus' of git://github.com/dledford/linux:
  MAINTAINERS: Update InfiniBand subsystem maintainer
  MAINTAINERS: add include/rdma/ to InfiniBand subsystem
  IPoIB/CM: Fix indentation level
  iw_cxgb4: Remove negative advice dmesg warnings
  IB/core: Fix unaligned accesses
  IB/core: change rdma_gid2ip into void function as it always return zero
  IB/qib: use arch_phys_wc_add()
  IB/qib: add acounting for MTRR
  IB/core: dma unmap optimizations
  IB/core: dma map/unmap locking optimizations
  RDMA/cxgb4: Report the actual address of the remote connecting peer
  RDMA/nes: Report the actual address of the remote connecting peer
  RDMA/core: Enable the iWarp Port Mapper to provide the actual address of the connecting peer to its clients
  iw_cxgb4: enforce qp/cq id requirements
  iw_cxgb4: use BAR2 GTS register for T5 kernel mode CQs
  iw_cxgb4: 32b platform fixes
  iw_cxgb4: Cleanup register defines/MACROS
  RDMA/CMA: Canonize IPv4 on IPV6 sockets properly
2015-05-07 07:04:33 -07:00
Chris Metcalf
83dedea8a0 nohz: Add tick_nohz_full_add_cpus_to() API
This API is useful to modify a cpumask indicating some special
nohz-type functionality so that the nohz cores are automatically
added to that set.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Jones <davej@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1429024675-18938-1-git-send-email-cmetcalf@ezchip.com
Link: http://lkml.kernel.org/r/1430928266-24888-4-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-07 12:02:51 +02:00
Frederic Weisbecker
fafe870f31 context_tracking: Inherit TIF_NOHZ through forks instead of context switches
TIF_NOHZ is used by context_tracking to force syscall slow-path
on every task in order to track userspace roundtrips. As such,
it must be set on all running tasks.

It's currently explicitly inherited through context switches.
There is no need to do it in this fast-path though. The flag
could simply be set once for all on all tasks, whether they are
running or not.

Lets do this by setting the flag for the init task on early boot,
and let it propagate through fork inheritance.

While at it, mark context_tracking_cpu_set() as init code, we
only need it at early boot time.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Dave Jones <davej@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430928266-24888-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-07 12:02:51 +02:00
Frederic Weisbecker
aed5ed4772 context_tracking: Protect against recursion
Context tracking recursion can happen when an exception triggers
in the middle of a call to a context tracking probe.

This special case can be caused by vmalloc faults. If an access
to a memory area allocated by vmalloc happens in the middle of
context_tracking_enter(), we may run into an endless fault loop
because the exception in turn calls context_tracking_enter()
which faults on the same vmalloc'ed memory, triggering an
exception again, etc...

Some rare crashes have been reported so lets protect against
this with a recursion counter.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430928266-24888-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-07 12:02:50 +02:00
Rik van Riel
653f52c316 kvm,x86: load guest FPU context more eagerly
Currently KVM will clear the FPU bits in CR0.TS in the VMCS, and trap to
re-load them every time the guest accesses the FPU after a switch back into
the guest from the host.

This patch copies the x86 task switch semantics for FPU loading, with the
FPU loaded eagerly after first use if the system uses eager fpu mode,
or if the guest uses the FPU frequently.

In the latter case, after loading the FPU for 255 times, the fpu_counter
will roll over, and we will revert to loading the FPU on demand, until
it has been established that the guest is still actively using the FPU.

This mirrors the x86 task switch policy, which seems to work.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-05-07 11:29:45 +02:00