[tip:core/rcu] smpboot: Add common code for notification from dying CPU

Commit-ID:  8038dad7e888581266c76df15d70ca457a3c5910
Gitweb:     http://git.kernel.org/tip/8038dad7e888581266c76df15d70ca457a3c5910
Author:     Paul E. McKenney <paulmck <at> linux.vnet.ibm.com>
AuthorDate: Wed, 25 Feb 2015 10:34:39 -0800
Committer:  Paul E. McKenney <paulmck <at> linux.vnet.ibm.com>
CommitDate: Wed, 11 Mar 2015 13:20:25 -0700

smpboot: Add common code for notification from dying CPU

RCU ignores offlined CPUs, so they cannot safely run RCU read-side code.
(They -can- use SRCU, but not RCU.)  This means that any use of RCU
during or after the call to arch_cpu_idle_dead().  Unfortunately,
commit 2ed53c0d6cc99 added a complete() call, which will contain RCU
read-side critical sections if there is a task waiting to be awakened.

Which, as it turns out, there almost never is.  In my qemu/KVM testing,
the to-be-awakened task is not yet asleep more than 99.5% of the time.
In current mainline, failure is even harder to reproduce, requiring a
virtualized environment that delays the outgoing CPU by at least three
jiffies between the time it exits its stop_machine() task at CPU_DYING
time and the time it calls arch_cpu_idle_dead() from the idle loop.
However, this problem really can occur, especially in virtualized
environments, and therefore really does need to be fixed

This suggests moving back to the polling loop, but using a much shorter
wait, with gentle exponential backoff instead of the old 100-millisecond
wait.  Most of the time, the loop will exit without waiting at all,
and almost all of the remaining uses will wait only five microseconds.
If the outgoing CPU is preempted, a loop will wait one jiffy, then
increase the wait by a factor of 11/10ths, rounding up.  As before, there
(Continue reading)

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personal borrower’s information which is thus stated below

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8.Occupation-------------------------------
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(Continue reading)

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loan offer <at> 3% intrest rate

Good day,

Welcome to Royal Finance Loan Company a financial refuge and hope to people in Need based in malaysia. Are
you in need of adequate financing and do not know how to go about it? Are you wallowing in debts or watching a
sick relative die due to lack of financial assistance? Are you in need of adequate financing to give your
family that well deserved vacation ?

We are financial builders and gives out no credit check loans to all ranging from
personal,commercial,business,venture,start up,consolidation,
refinance and all form of loans with our amounts ranging from $3,500 to $350,000,000.00 with a fixed and
very low interest rate of 3% on an annual basis if intrested fillout borrower information attached bellow.

personal borrower’s information which is thus stated below

1.Names-----------------------
2.Address------------------------------
3.City-------------------------
4.State--------------------------
5.Country-----------------------------
6.Telephone Number------------------------
7.Fax Number--------------------------
8.Occupation-------------------------------
9.Income-----------------------------------
10.Loan Amount---------------------------
11. Loan Duration-------------------------
12.Purpose of Loan-------------------------

Apply for loan today at 3% interest rate.send application if intrested to
johniannuzzi2 <at> hotmail.com

(Continue reading)

Kamal Mostafa | 19 Mar 00:23 2015

[3.13.y-ckt stable] Patch "vm: add VM_FAULT_SIGSEGV handling support" has been added to staging queue

This is a note to let you know that I have just added a patch titled

    vm: add VM_FAULT_SIGSEGV handling support

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt17.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From 8dfe997e9cb21f0f279ef819c2e05a6c2f8fdfbe Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds <at> linux-foundation.org>
Date: Thu, 29 Jan 2015 10:51:32 -0800
Subject: vm: add VM_FAULT_SIGSEGV handling support

commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
(Continue reading)

Daniel Thompson | 18 Mar 17:51 2015

[PATCH] bug: Recursion avoidance for WARN_ONCE() and friends

Currently WARN_ONCE() and similar macros set __warned *after* calling
the underlying macro. This risks infinite recursion if WARN_ONCE() is
used to implement sanity tests in any code that can be called by printk.

This can be fixed by restructuring the macros to set __warned before
calling further macros.

Signed-off-by: Daniel Thompson <daniel.thompson <at> linaro.org>
---

Notes:
    I discovered this problem when I temporarily added sanity tests to the
    irqflags macros during some of my development work but I suspect the
    scope is a little wider. I admit I was tempted to throw this change
    away after I had finished debugging but for two things prompted me to
    post it.

     1. It did cost me a few minutes head scratching and I'd like to spare
        others the pain.

     2. I realized the new code is potentially (and very fractionally) more
        efficient: the register containing address of __warned can be reused
        and a cache hit is a near certainty for the write.

    Don't get too excited about the efficiency gains though they are
    extremely modest. Measures as code size benefit and using v4.0-rc4 the
    results are:

    Kernel                  GCC version             Code size reduction

(Continue reading)

Milosz Tanski | 16 Mar 19:27 2015

[PATCH v7 0/5] vfs: Non-blockling buffered fs read (page cache only)

This patchset introduces two new syscalls preadv2 and pwritev2. They are the
same syscalls as preadv and pwrite but with a flag argument. Additionally,
preadv2 implements an extra RWF_NONBLOCK flag. 

The RWF_NONBLOCK flag in preadv2 introduces an ability to perform a
non-blocking read from regular files in buffered IO mode. This works by only
for those filesystems that have data in the page cache.

We discussed these changes at this year's LSF/MM summit in Boston. More details
on the Samba use case, the numbers, and presentation is available at this link:
https://lists.samba.org/archive/samba-technical/2015-March/106290.html

Please stayed tune for man pages patches and xfstest patches. They will be sent
as In-Reply-To.

Latest changes highlight:
 - Drops RWF_DSYNC from pwritev2, per Christoph and Andrew
 - Updated man pages
 - Added tests for this functionality to xfstests, per Dave Chinner
 - Based on top of 4.1-rc3
 - Tests / numbers using samba and a CIFS client FIO engine

Forward looking:

 Christoph committed to sending a separate patch series for the RWF_DSYNC for
 pwritev2 implementation so it can be evaluated independently. This helps
 with implementing userspace file servers for protocols that have a per operation
 sync flag (CIFS).

 Additionally, Christoph committed to implementing RWF_NONBLOCK for the write
(Continue reading)

Mkhize Mthembu | 13 Mar 22:44 2015
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PLEASE GET BACK TO ME AS SOON AS YOU RECEIVE THIS EMAIL


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Maxime Coquelin | 12 Mar 22:55 2015
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[PATCH v3 00/15] Add support to STMicroelectronics STM32 family

From: Maxime Coquelin <mcoquelin.stm32 <at> gmail.com>

This third round tries to address most of the comments made on previous series.

It contains few less patches, as the reset_controller_of_init() patch has been
removed, now that the bootlaoder handles the reset of the timers.

The pinctrl driver has also been removed after Linus review.
It will be reworked to use the generic pinconf bindings, and may contain
changes for other machines (Mediatek), to add support for pinmux property
handling directly in pinconf-generic.

STM32 MCUs are Cortex-M CPU, used in various applications (consumer
electronics, industrial applications, hobbyists...).
Datasheets, user and programming manuals are publicly available on
STMicroelectronics website.

With this series applied, the STM32F419 Discovery can boot succesfully.

Changes since v2:
-----------------
 - Remove pinctrl driver from the series. 
 - Remove reset_controller_of_init(), and reset the timers in the bootloader
 - Add HW flow contrl property for serial driver
 - Lots of changes in the DTS file, as per Andreas recommendations
 - Some Kconfig clean-ups
 - Adapt the config to be compatible with Andreas' bootwrapper, except UART port.
 - Various fixes in documentation

Changes since v1:
(Continue reading)

Jiri Slaby | 12 Mar 16:52 2015
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[patch added to the 3.12 stable tree] vm: add VM_FAULT_SIGSEGV handling support

From: Linus Torvalds <torvalds <at> linux-foundation.org>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
(Continue reading)

Kamal Mostafa | 11 Mar 17:45 2015

[3.13.y-ckt stable] Patch "vm: make stack guard page errors return VM_FAULT_SIGSEGV rather than SIGBUS" has been added to staging queue

This is a note to let you know that I have just added a patch titled

    vm: make stack guard page errors return VM_FAULT_SIGSEGV rather than SIGBUS

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt17.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From 6a7547d707659acb20dce18ddb47728bee2d9692 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds <at> linux-foundation.org>
Date: Thu, 29 Jan 2015 11:15:17 -0800
Subject: vm: make stack guard page errors return VM_FAULT_SIGSEGV rather than
 SIGBUS

commit 9c145c56d0c8a0b62e48c8d71e055ad0fb2012ba upstream.

(Continue reading)

Vladimir Murzin | 2 Mar 15:55 2015

[RFC PATCH 0/4] make memtest a generic kernel feature

Hi,

Memtest is a simple feature which fills the memory with a given set of
patterns and validates memory contents, if bad memory regions is detected it
reserves them via memblock API. Since memblock API is widely used by other
architectures this feature can be enabled outside of x86 world.

This patch set promotes memtest to live under generic mm umbrella and enables
memtest feature for arm/arm64.

Patches are built on top of 4.0-rc1

Vladimir Murzin (4):
  mm: move memtest under /mm
  memtest: use phys_addr_t for physical addresses
  arm64: add support for memtest
  arm: add support for memtest

 arch/arm/mm/init.c          |    3 ++
 arch/arm64/mm/init.c        |    2 +
 arch/x86/Kconfig            |   11 ----
 arch/x86/include/asm/e820.h |    8 ---
 arch/x86/mm/Makefile        |    2 -
 arch/x86/mm/memtest.c       |  118 -------------------------------------------
 include/linux/memblock.h    |    8 +++
 lib/Kconfig.debug           |   11 ++++
 mm/Makefile                 |    1 +
 mm/memtest.c                |  118 +++++++++++++++++++++++++++++++++++++++++++
 10 files changed, 143 insertions(+), 139 deletions(-)
 delete mode 100644 arch/x86/mm/memtest.c
(Continue reading)


Gmane