* 'stable/vmalloc-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
net: xen-netback: use API provided by xenbus module to map rings
block: xen-blkback: use API provided by xenbus module to map rings
xen: use generic functions instead of xen_{alloc, free}_vm_area()
The legacy x86 nmi watchdog code was removed with the implementation
of the perf based nmi watchdog. This broke Oprofile's nmi timer
mode. To run nmi timer mode we relied on a continuous ticking nmi
source which the nmi watchdog provided. The nmi tick was no longer
available and current watchdog can not be used anymore since it runs
with very long periods in the range of seconds. This patch
reimplements the nmi timer mode using a perf counter nmi source.
V2:
* removing pr_info()
* fix undefined reference to `__udivdi3' for 32 bit build
* fix section mismatch of .cpuinit.data:nmi_timer_cpu_nb
* removed nmi timer setup in arch/x86
* implemented function stubs for op_nmi_init/exit()
* made code more readable in oprofile_init()
V3:
* fix architectural initialization in oprofile_init()
* fix CONFIG_OPROFILE_NMI_TIMER dependencies
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Robert Richter <robert.richter@amd.com>
We need this to better test x86 NMI timer mode. Otherwise it is very
hard to setup systems with NMI timer enabled, but we have this e.g. in
virtual machine environments.
Signed-off-by: Robert Richter <robert.richter@amd.com>
* 'for-next' of git://git.infradead.org/users/sameo/mfd-2.6: (80 commits)
mfd: Fix missing abx500 header file updates
mfd: Add missing <linux/io.h> include to intel_msic
x86, mrst: add platform support for MSIC MFD driver
mfd: Expose TurnOnStatus in ab8500 sysfs
mfd: Remove support for early drop ab8500 chip
mfd: Add support for ab8500 v3.3
mfd: Add ab8500 interrupt disable hook
mfd: Convert db8500-prcmu panic() into pr_crit()
mfd: Refactor db8500-prcmu request_clock() function
mfd: Rename db8500-prcmu init function
mfd: Fix db5500-prcmu defines
mfd: db8500-prcmu voltage domain consumers additions
mfd: db8500-prcmu reset code retrieval
mfd: db8500-prcmu tweak for modem wakeup
mfd: Add db8500-pcmu watchdog accessor functions for watchdog
mfd: hwacc power state db8500-prcmu accessor
mfd: Add db8500-prcmu accessors for PLL and SGA clock
mfd: Move to the new db500 PRCMU API
mfd: Create a common interface for dbx500 PRCMU drivers
mfd: Initialize DB8500 PRCMU regs
...
Fix up trivial conflicts in
arch/arm/mach-imx/mach-mx31moboard.c
arch/arm/mach-omap2/board-omap3beagle.c
arch/arm/mach-u300/include/mach/irqs.h
drivers/mfd/wm831x-spi.c
* 'linux_next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac: (21 commits)
MAINTAINERS: add an entry for Edac Sandy Bridge driver
edac: tag sb_edac as EXPERIMENTAL, as it requires more testing
EDAC: Fix incorrect edac mode reporting in sb_edac
edac: sb_edac: Add it to the building system
edac: Add an experimental new driver to support Sandy Bridge CPU's
i7300_edac: Fix error cleanup logic
i7core_edac: Initialize memory name with cpu, channel, bank
i7core_edac: Fix compilation on 32 bits arch
i7core_edac: scrubbing fixups
EDAC: Correct Kconfig dependencies
i7core_edac: return -ENODEV if no MC is found
i7core_edac: use edac's own way to print errors
MAINTAINERS: remove dropped edac_mce.* from the file
i7core_edac: Drop the edac_mce facility
x86, MCE: Use notifier chain only for MCE decoding
EDAC i7core: Use mce socketid for better compatibility
i7core_edac: Don't enable memory scrubbing for Xeon 35xx
i7core_edac: Add scrubbing support
edac: Move edac main structs to include/linux/edac.h
i7core_edac: Fix oops when trying to inject errors
...
Says Andrew:
"60 patches. That's good enough for -rc1 I guess. I have quite a lot
of detritus to be rechecked, work through maintainers, etc.
- most of the remains of MM
- rtc
- various misc
- cgroups
- memcg
- cpusets
- procfs
- ipc
- rapidio
- sysctl
- pps
- w1
- drivers/misc
- aio"
* akpm: (60 commits)
memcg: replace ss->id_lock with a rwlock
aio: allocate kiocbs in batches
drivers/misc/vmw_balloon.c: fix typo in code comment
drivers/misc/vmw_balloon.c: determine page allocation flag can_sleep outside loop
w1: disable irqs in critical section
drivers/w1/w1_int.c: multiple masters used same init_name
drivers/power/ds2780_battery.c: fix deadlock upon insertion and removal
drivers/power/ds2780_battery.c: add a nolock function to w1 interface
drivers/power/ds2780_battery.c: create central point for calling w1 interface
w1: ds2760 and ds2780, use ida for id and ida_simple_get() to get it
pps gpio client: add missing dependency
pps: new client driver using GPIO
pps: default echo function
include/linux/dma-mapping.h: add dma_zalloc_coherent()
sysctl: make CONFIG_SYSCTL_SYSCALL default to n
sysctl: add support for poll()
RapidIO: documentation update
drivers/net/rionet.c: fix ethernet address macros for LE platforms
RapidIO: fix potential null deref in rio_setup_device()
RapidIO: add mport driver for Tsi721 bridge
...
Michel while working on the working set estimation code, noticed that
calling get_page_unless_zero() on a random pfn_to_page(random_pfn)
wasn't safe, if the pfn ended up being a tail page of a transparent
hugepage under splitting by __split_huge_page_refcount().
He then found the problem could also theoretically materialize with
page_cache_get_speculative() during the speculative radix tree lookups
that uses get_page_unless_zero() in SMP if the radix tree page is freed
and reallocated and get_user_pages is called on it before
page_cache_get_speculative has a chance to call get_page_unless_zero().
So the best way to fix the problem is to keep page_tail->_count zero at
all times. This will guarantee that get_page_unless_zero() can never
succeed on any tail page. page_tail->_mapcount is guaranteed zero and
is unused for all tail pages of a compound page, so we can simply
account the tail page references there and transfer them to
tail_page->_count in __split_huge_page_refcount() (in addition to the
head_page->_mapcount).
While debugging this s/_count/_mapcount/ change I also noticed get_page is
called by direct-io.c on pages returned by get_user_pages. That wasn't
entirely safe because the two atomic_inc in get_page weren't atomic. As
opposed to other get_user_page users like secondary-MMU page fault to
establish the shadow pagetables would never call any superflous get_page
after get_user_page returns. It's safer to make get_page universally safe
for tail pages and to use get_page_foll() within follow_page (inside
get_user_pages()). get_page_foll() is safe to do the refcounting for tail
pages without taking any locks because it is run within PT lock protected
critical sections (PT lock for pte and page_table_lock for
pmd_trans_huge).
The standard get_page() as invoked by direct-io instead will now take
the compound_lock but still only for tail pages. The direct-io paths
are usually I/O bound and the compound_lock is per THP so very
finegrined, so there's no risk of scalability issues with it. A simple
direct-io benchmarks with all lockdep prove locking and spinlock
debugging infrastructure enabled shows identical performance and no
overhead. So it's worth it. Ideally direct-io should stop calling
get_page() on pages returned by get_user_pages(). The spinlock in
get_page() is already optimized away for no-THP builds but doing
get_page() on tail pages returned by GUP is generally a rare operation
and usually only run in I/O paths.
This new refcounting on page_tail->_mapcount in addition to avoiding new
RCU critical sections will also allow the working set estimation code to
work without any further complexity associated to the tail page
refcounting with THP.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://github.com/richardweinberger/linux: (90 commits)
um: fix ubd cow size
um: Fix kmalloc argument order in um/vdso/vma.c
um: switch to use of drivers/Kconfig
UserModeLinux-HOWTO.txt: fix a typo
UserModeLinux-HOWTO.txt: remove ^H characters
um: we need sys/user.h only on i386
um: merge delay_{32,64}.c
um: distribute exports to where exported stuff is defined
um: kill system-um.h
um: generic ftrace.h will do...
um: segment.h is x86-only and needed only there
um: asm/pda.h is not needed anymore
um: hw_irq.h can go generic as well
um: switch to generic-y
um: clean Kconfig up a bit
um: a couple of missing dependencies...
um: kill useless argument of free_chan() and free_one_chan()
um: unify ptrace_user.h
um: unify KSTK_...
um: fix gcov build breakage
...
kmalloc size is 1st arg, not second.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Cc: <stable@kernel.org> # 3.0.x
[richard@nod.at: on 3.0 the to be patched file is
arch/um/sys-x86_64/vdso/vma.c]
... and switch get_thread_register() to HOST_... for register numbers
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
a) exports in gmon_syms.c duplicate kernel/gcov/* ones
b) excluding -pg in vdso compile is not enough - -fprofile-arcs
and -ftest-coverage also needs to be excluded
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
it's x86-only and we have no business playing with it in asm/mmu.h; make
the latter have
struct uml_arch_mm_context arch;
instead of
struct uml_ldt ldt;
and let arch/<subarch>/um/asm/mm_context.h decide what'll be in there.
While we are at it, kill host_ldt.h - it's not needed in part of places
that include it (we want asm/ldt.h in those) and it can be trivially
expanded into the single remaining one.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
Linus Torvalds
Len Brown
Robert Richter
Andrea Arcangeli
Dave Jones
Richard Weinberger
Al Viro