Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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Pull x86 fix from Thomas Gleixner:
"A single fix to unbreak the vdso32 build for 64bit kernels caused by
excess #includes in the mshyperv header"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mshyperv: Remove excess #includes from mshyperv.h
Pull timer fixes from Thomas Gleixner:
"A few fixes for timekeeping and timers:
- Plug a subtle race due to a missing READ_ONCE() in the timekeeping
code where reloading of a pointer results in an inconsistent
callback argument being supplied to the clocksource->read function.
- Correct the CLOCK_MONOTONIC_RAW sub-nanosecond accounting in the
time keeping core code, to prevent a possible discontuity.
- Apply a similar fix to the arm64 vdso clock_gettime()
implementation
- Add missing includes to clocksource drivers, which relied on
indirect includes which fails in certain configs.
- Use the proper iomem pointer for read/iounmap in a probe function"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
arm64/vdso: Fix nsec handling for CLOCK_MONOTONIC_RAW
time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting
time: Fix clock->read(clock) race around clocksource changes
clocksource: Explicitly include linux/clocksource.h when needed
clocksource/drivers/arm_arch_timer: Fix read and iounmap of incorrect variable
A recent commit included linux/slab.h in linux/irq.h. This breaks the build
of vdso32 on a 64-bit kernel.
The reason is that linux/irq.h gets included into the vdso code via
linux/interrupt.h which is included from asm/mshyperv.h. That makes the
32-bit vdso compile fail, because slab.h includes the pgtable headers for
64-bit on a 64-bit build.
Neither linux/clocksource.h nor linux/interrupt.h are needed in the
mshyperv.h header file itself - it has a dependency on <linux/atomic.h>.
Remove the includes and unbreak the build.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: devel@linuxdriverproject.org
Fixes: dee863b571b0 ("hv: export current Hyper-V clocksource")
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1706231038460.2647@nanos
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf fixes from Thomas Gleixner:
"Three fixlets for perf:
- Return the proper error code if aux buffers for a event are not
supported.
- Calculate the probe offset for inlined functions correctly
- Update the Skylake DTLB load/store miss event so it can count 1G
TLB entries as well"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf probe: Fix probe definition for inlined functions
perf/x86/intel: Add 1G DTLB load/store miss support for SKL
perf/aux: Correct return code of rb_alloc_aux() if !has_aux(ev)
Pull clockevents fixes from Daniel Lezcano:
- Fixed wrong iomem area unmapped in the arch_arm_timer (Frank Rowand)
- Added missing includes for sun5i and cadence-ttc (Stephen Rothwell)
Pull block fixes from Jens Axboe:
"This contains a set of fixes for xen-blkback by way of Konrad, and a
performance regression fix for blk-mq for shared tags.
The latter could account for as much as a 50x reduction in
performance, with the test case from the user with 500 name spaces. A
more realistic setup on my end with 32 drives showed a 3.5x drop. The
fix has been thoroughly tested before being committed"
* 'for-linus' of git://git.kernel.dk/linux-block:
blk-mq: fix performance regression with shared tags
xen-blkback: don't leak stack data via response ring
xen/blkback: don't use xen_blkif_get() in xen-blkback kthread
xen/blkback: don't free be structure too early
xen/blkback: fix disconnect while I/Os in flight
Pull irq fix from Thomas Gleixner:
"A single fix for the MIPS GIC to prevent ftrace recursion"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/mips-gic: Mark count and compare accessors notrace
Pull 'perf probe' fix from Arnaldo Carvalho de Melo:
- Do not double the offset of inline expansions when using
'perf probe' on inlined functions (Björn Töpel)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Recently vDSO support for CLOCK_MONOTONIC_RAW was added in
49eea433b326 ("arm64: Add support for CLOCK_MONOTONIC_RAW in
clock_gettime() vDSO"). Noticing that the core timekeeping code
never set tkr_raw.xtime_nsec, the vDSO implementation didn't
bother exposing it via the data page and instead took the
unshifted tk->raw_time.tv_nsec value which was then immediately
shifted left in the vDSO code.
Unfortunately, by accellerating the MONOTONIC_RAW clockid, it
uncovered potential 1ns time inconsistencies caused by the
timekeeping core not handing sub-ns resolution.
Now that the core code has been fixed and is actually setting
tkr_raw.xtime_nsec, we need to take that into account in the
vDSO by adding it to the shifted raw_time value, in order to
fix the user-visible inconsistency. Rather than do that at each
use (and expand the data page in the process), instead perform
the shift/addition operation when populating the data page and
remove the shift from the vDSO code entirely.
[jstultz: minor whitespace tweak, tried to improve commit
message to make it more clear this fixes a regression]
Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Daniel Mentz <danielmentz@google.com>
Acked-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: "stable #4 . 8+" <stable@vger.kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Link: http://lkml.kernel.org/r/1496965462-20003-4-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The kbuild test robot reported errors in these files when doing an ia64
allmodconfig build.
drivers/clocksource/timer-sun5i.c:52:21: error: field 'clksrc' has incomplete type
struct clocksource clksrc;
^~~~~~
drivers/clocksource/cadence_ttc_timer.c:92:21: error: field 'cs' has incomplete type
struct clocksource cs;
^~
(and many more errors for these files)
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Pull networking fixes from David Miller:
1) Fix refcounting wrt timers which hold onto inet6 address objects,
from Xin Long.
2) Fix an ancient bug in wireless wext ioctls, from Johannes Berg.
3) Firmware handling fixes in brcm80211 driver, from Arend Van Spriel.
4) Several mlx5 driver fixes (firmware readiness, timestamp cap
reporting, devlink command validity checking, tc offloading, etc.)
From Eli Cohen, Maor Dickman, Chris Mi, and Or Gerlitz.
5) Fix dst leak in IP/IP6 tunnels, from Haishuang Yan.
6) Fix dst refcount bug in decnet, from Wei Wang.
7) Netdev can be double freed in register_vlan_device(). Fix from Gao
Feng.
8) Don't allow object to be destroyed while it is being dumped in SCTP,
from Xin Long.
9) Fix dpaa_eth build when modular, from Madalin Bucur.
10) Fix throw route leaks, from Serhey Popovych.
11) IFLA_GROUP missing from if_nlmsg_size() and ifla_policy[] table,
also from Serhey Popovych.
12) Fix premature TX SKB free in stmmac, from Niklas Cassel.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (36 commits)
igmp: add a missing spin_lock_init()
net: stmmac: free an skb first when there are no longer any descriptors using it
sfc: remove duplicate up_write on VF filter_sem
rtnetlink: add IFLA_GROUP to ifla_policy
ipv6: Do not leak throw route references
dt-bindings: net: sms911x: Add missing optional VDD regulators
dpaa_eth: reuse the dma_ops provided by the FMan MAC device
fsl/fman: propagate dma_ops
net/core: remove explicit do_softirq() from busy_poll_stop()
fib_rules: Resolve goto rules target on delete
sctp: ensure ep is not destroyed before doing the dump
net/hns:bugfix of ethtool -t phy self_test
net: 8021q: Fix one possible panic caused by BUG_ON in free_netdev
cxgb4: notify uP to route ctrlq compl to rdma rspq
ip6_tunnel: Correct tos value in collect_md mode
decnet: always not take dst->__refcnt when inserting dst into hash table
ip6_tunnel: fix potential issue in __ip6_tnl_rcv
ip_tunnel: fix potential issue in ip_tunnel_rcv
brcmfmac: fix uninitialized warning in brcmf_usb_probe_phase2()
net/mlx5e: Avoid doing a cleanup call if the profile doesn't have it
...
If we have shared tags enabled, then every IO completion will trigger
a full loop of every queue belonging to a tag set, and every hardware
queue for each of those queues, even if nothing needs to be done.
This causes a massive performance regression if you have a lot of
shared devices.
Instead of doing this huge full scan on every IO, add an atomic
counter to the main queue that tracks how many hardware queues have
been marked as needing a restart. With that, we can avoid looking for
restartable queues, if we don't have to.
Max reports that this restores performance. Before this patch, 4K
IOPS was limited to 22-23K IOPS. With the patch, we are running at
950-970K IOPS.
Fixes: 6d8c6c0f97ad ("blk-mq: Restart a single queue if tag sets are shared")
Reported-by: Max Gurtovoy <maxg@mellanox.com>
Tested-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull input fixes from Dmitry Torokhov:
- a quirk to i8042 to ignore timeout bit on Lifebook AH544
- a fixup to Synaptics RMI function 54 that was breaking some Dells
- a fix for memory leak in soc_button_array driver
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: synaptics-rmi4 - only read the F54 query registers which are used
Input: i8042 - add Fujitsu Lifebook AH544 to notimeout list
Input: soc_button_array - fix leaking the ACPI button descriptor buffer