Go to file
John Stultz 3d88d56c58 time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting
Due to how the MONOTONIC_RAW accumulation logic was handled,
there is the potential for a 1ns discontinuity when we do
accumulations. This small discontinuity has for the most part
gone un-noticed, but since ARM64 enabled CLOCK_MONOTONIC_RAW
in their vDSO clock_gettime implementation, we've seen failures
with the inconsistency-check test in kselftest.

This patch addresses the issue by using the same sub-ns
accumulation handling that CLOCK_MONOTONIC uses, which avoids
the issue for in-kernel users.

Since the ARM64 vDSO implementation has its own clock_gettime
calculation logic, this patch reduces the frequency of errors,
but failures are still seen. The ARM64 vDSO will need to be
updated to include the sub-nanosecond xtime_nsec values in its
calculation for this issue to be completely fixed.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Daniel Mentz <danielmentz@google.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "stable #4 . 8+" <stable@vger.kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Link: http://lkml.kernel.org/r/1496965462-20003-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-06-20 10:41:50 +02:00
Documentation mm: larger stack guard gap, between vmas 2017-06-19 21:50:20 +08:00
arch mm: larger stack guard gap, between vmas 2017-06-19 21:50:20 +08:00
block block: Fix a blk_exit_rl() regression 2017-06-14 13:27:50 -06:00
certs scripts/spelling.txt: add "intialise(d)" pattern and fix typo instances 2017-05-08 17:15:13 -07:00
crypto crypto : asymmetric_keys : verify_pefile:zero memory content before freeing 2017-06-09 13:29:50 +10:00
drivers virtio: bugfix 2017-06-19 09:25:05 +09:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs mm: larger stack guard gap, between vmas 2017-06-19 21:50:20 +08:00
include time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting 2017-06-20 10:41:50 +02:00
init Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-10 10:30:46 -07:00
ipc mm: introduce kv[mz]alloc helpers 2017-05-08 17:15:12 -07:00
kernel time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting 2017-06-20 10:41:50 +02:00
lib Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-06-15 17:54:51 +09:00
mm mm: larger stack guard gap, between vmas 2017-06-19 21:50:20 +08:00
net net: don't global ICMP rate limit packets originating from loopback 2017-06-14 15:33:58 -04:00
samples samples/bpf: run cleanup routines when receiving SIGTERM 2017-05-11 21:43:30 -04:00
scripts scripts/gdb: make lx-dmesg command work (reliably) 2017-06-02 15:07:38 -07:00
security selinux: fix double free in selinux_parse_opts_str() 2017-06-13 17:34:22 +10:00
sound ALSA: timer: Fix missing queue indices reset at SNDRV_TIMER_IOCTL_SELECT 2017-06-07 10:25:23 +02:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-06-18 18:42:31 +09:00
usr initramfs: fix disabling of initramfs (and its compression) 2017-06-02 15:07:37 -07:00
virt KVM: arm/arm64: Handle possible NULL stage2 pud when ageing pages 2017-06-06 15:28:40 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS A few overdue GPIO patches for the v4.12 kernel: 2017-06-11 11:34:27 -07:00
Makefile Linux 4.12-rc6 2017-06-19 22:19:37 +08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

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.