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  1. 07 7月, 2017 5 次提交
    • A
      mm/hugetlb: clean up ARCH_HAS_GIGANTIC_PAGE · e1073d1e
      由 Aneesh Kumar K.V 提交于 
      This moves the #ifdef in C code to a Kconfig dependency.  Also we move
the gigantic_page_supported() function to be arch specific.

This allows architectures to conditionally enable runtime allocation of
gigantic huge page.  Architectures like ppc64 supports different
gigantic huge page size (16G and 1G) based on the translation mode
selected.  This provides an opportunity for ppc64 to enable runtime
allocation only w.r.t 1G hugepage.

No functional change in this patch.

Link: http://lkml.kernel.org/r/1494995292-4443-1-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e1073d1e
    • M
      mm, memory_hotplug: replace for_device by want_memblock in arch_add_memory · 3d79a728
      由 Michal Hocko 提交于 
      arch_add_memory gets for_device argument which then controls whether we
want to create memblocks for created memory sections.  Simplify the
logic by telling whether we want memblocks directly rather than going
through pointless negation.  This also makes the api easier to
understand because it is clear what we want rather than nothing telling
for_device which can mean anything.

This shouldn't introduce any functional change.

Link: http://lkml.kernel.org/r/20170515085827.16474-13-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Tested-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Tobias Regnery <tobias.regnery@gmail.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3d79a728
    • M
      mm, memory_hotplug: do not associate hotadded memory to zones until online · f1dd2cd1
      由 Michal Hocko 提交于 
      The current memory hotplug implementation relies on having all the
struct pages associate with a zone/node during the physical hotplug
phase (arch_add_memory->__add_pages->__add_section->__add_zone).  In the
vast majority of cases this means that they are added to ZONE_NORMAL.
This has been so since 9d99aaa3 ("[PATCH] x86_64: Support memory
hotadd without sparsemem") and it wasn't a big deal back then because
movable onlining didn't exist yet.

Much later memory hotplug wanted to (ab)use ZONE_MOVABLE for movable
onlining 511c2aba ("mm, memory-hotplug: dynamic configure movable
memory and portion memory") and then things got more complicated.
Rather than reconsidering the zone association which was no longer
needed (because the memory hotplug already depended on SPARSEMEM) a
convoluted semantic of zone shifting has been developed.  Only the
currently last memblock or the one adjacent to the zone_movable can be
onlined movable.  This essentially means that the online type changes as
the new memblocks are added.

Let's simulate memory hot online manually
  $ echo 0x100000000 > /sys/devices/system/memory/probe
  $ grep . /sys/devices/system/memory/memory32/valid_zones
  Normal Movable

  $ echo $((0x100000000+(128<<20))) > /sys/devices/system/memory/probe
  $ grep . /sys/devices/system/memory/memory3?/valid_zones
  /sys/devices/system/memory/memory32/valid_zones:Normal
  /sys/devices/system/memory/memory33/valid_zones:Normal Movable

  $ echo $((0x100000000+2*(128<<20))) > /sys/devices/system/memory/probe
  $ grep . /sys/devices/system/memory/memory3?/valid_zones
  /sys/devices/system/memory/memory32/valid_zones:Normal
  /sys/devices/system/memory/memory33/valid_zones:Normal
  /sys/devices/system/memory/memory34/valid_zones:Normal Movable

  $ echo online_movable > /sys/devices/system/memory/memory34/state
  $ grep . /sys/devices/system/memory/memory3?/valid_zones
  /sys/devices/system/memory/memory32/valid_zones:Normal
  /sys/devices/system/memory/memory33/valid_zones:Normal Movable
  /sys/devices/system/memory/memory34/valid_zones:Movable Normal

This is an awkward semantic because an udev event is sent as soon as the
block is onlined and an udev handler might want to online it based on
some policy (e.g.  association with a node) but it will inherently race
with new blocks showing up.

This patch changes the physical online phase to not associate pages with
any zone at all.  All the pages are just marked reserved and wait for
the onlining phase to be associated with the zone as per the online
request.  There are only two requirements

	- existing ZONE_NORMAL and ZONE_MOVABLE cannot overlap

	- ZONE_NORMAL precedes ZONE_MOVABLE in physical addresses

the latter one is not an inherent requirement and can be changed in the
future.  It preserves the current behavior and made the code slightly
simpler.  This is subject to change in future.

This means that the same physical online steps as above will lead to the
following state: Normal Movable

  /sys/devices/system/memory/memory32/valid_zones:Normal Movable
  /sys/devices/system/memory/memory33/valid_zones:Normal Movable

  /sys/devices/system/memory/memory32/valid_zones:Normal Movable
  /sys/devices/system/memory/memory33/valid_zones:Normal Movable
  /sys/devices/system/memory/memory34/valid_zones:Normal Movable

  /sys/devices/system/memory/memory32/valid_zones:Normal Movable
  /sys/devices/system/memory/memory33/valid_zones:Normal Movable
  /sys/devices/system/memory/memory34/valid_zones:Movable

Implementation:
The current move_pfn_range is reimplemented to check the above
requirements (allow_online_pfn_range) and then updates the respective
zone (move_pfn_range_to_zone), the pgdat and links all the pages in the
pfn range with the zone/node.  __add_pages is updated to not require the
zone and only initializes sections in the range.  This allowed to
simplify the arch_add_memory code (s390 could get rid of quite some of
code).

devm_memremap_pages is the only user of arch_add_memory which relies on
the zone association because it only hooks into the memory hotplug only
half way.  It uses it to associate the new memory with ZONE_DEVICE but
doesn't allow it to be {on,off}lined via sysfs.  This means that this
particular code path has to call move_pfn_range_to_zone explicitly.

The original zone shifting code is kept in place and will be removed in
the follow up patch for an easier review.

Please note that this patch also changes the original behavior when
offlining a memory block adjacent to another zone (Normal vs.  Movable)
used to allow to change its movable type.  This will be handled later.

[richard.weiyang@gmail.com: simplify zone_intersects()]
  Link: http://lkml.kernel.org/r/20170616092335.5177-1-richard.weiyang@gmail.com
[richard.weiyang@gmail.com: remove duplicate call for set_page_links]
  Link: http://lkml.kernel.org/r/20170616092335.5177-2-richard.weiyang@gmail.com
[akpm@linux-foundation.org: remove unused local `i']
Link: http://lkml.kernel.org/r/20170515085827.16474-12-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NWei Yang <richard.weiyang@gmail.com>
Tested-by: NDan Williams <dan.j.williams@intel.com>
Tested-by: NReza Arbab <arbab@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # For s390 bits
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Tobias Regnery <tobias.regnery@gmail.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f1dd2cd1
    • M
      mm, memory_hotplug: get rid of is_zone_device_section · 1b862aec
      由 Michal Hocko 提交于 
      Device memory hotplug hooks into regular memory hotplug only half way.
It needs memory sections to track struct pages but there is no
need/desire to associate those sections with memory blocks and export
them to the userspace via sysfs because they cannot be onlined anyway.

This is currently expressed by for_device argument to arch_add_memory
which then makes sure to associate the given memory range with
ZONE_DEVICE.  register_new_memory then relies on is_zone_device_section
to distinguish special memory hotplug from the regular one.  While this
works now, later patches in this series want to move __add_zone outside
of arch_add_memory path so we have to come up with something else.

Add want_memblock down the __add_pages path and use it to control
whether the section->memblock association should be done.
arch_add_memory then just trivially want memblock for everything but
for_device hotplug.

remove_memory_section doesn't need is_zone_device_section either.  We
can simply skip all the memblock specific cleanup if there is no
memblock for the given section.

This shouldn't introduce any functional change.

Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Tested-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Tobias Regnery <tobias.regnery@gmail.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1b862aec
    • H
      mm, THP, swap: delay splitting THP during swap out · 38d8b4e6
      由 Huang Ying 提交于 
      Patch series "THP swap: Delay splitting THP during swapping out", v11.

This patchset is to optimize the performance of Transparent Huge Page
(THP) swap.

Recently, the performance of the storage devices improved so fast that
we cannot saturate the disk bandwidth with single logical CPU when do
page swap out even on a high-end server machine.  Because the
performance of the storage device improved faster than that of single
logical CPU.  And it seems that the trend will not change in the near
future.  On the other hand, the THP becomes more and more popular
because of increased memory size.  So it becomes necessary to optimize
THP swap performance.

The advantages of the THP swap support include:

 - Batch the swap operations for the THP to reduce lock
   acquiring/releasing, including allocating/freeing the swap space,
   adding/deleting to/from the swap cache, and writing/reading the swap
   space, etc. This will help improve the performance of the THP swap.

 - The THP swap space read/write will be 2M sequential IO. It is
   particularly helpful for the swap read, which are usually 4k random
   IO. This will improve the performance of the THP swap too.

 - It will help the memory fragmentation, especially when the THP is
   heavily used by the applications. The 2M continuous pages will be
   free up after THP swapping out.

 - It will improve the THP utilization on the system with the swap
   turned on. Because the speed for khugepaged to collapse the normal
   pages into the THP is quite slow. After the THP is split during the
   swapping out, it will take quite long time for the normal pages to
   collapse back into the THP after being swapped in. The high THP
   utilization helps the efficiency of the page based memory management
   too.

There are some concerns regarding THP swap in, mainly because possible
enlarged read/write IO size (for swap in/out) may put more overhead on
the storage device.  To deal with that, the THP swap in should be turned
on only when necessary.  For example, it can be selected via
"always/never/madvise" logic, to be turned on globally, turned off
globally, or turned on only for VMA with MADV_HUGEPAGE, etc.

This patchset is the first step for the THP swap support.  The plan is
to delay splitting THP step by step, finally avoid splitting THP during
the THP swapping out and swap out/in the THP as a whole.

As the first step, in this patchset, the splitting huge page is delayed
from almost the first step of swapping out to after allocating the swap
space for the THP and adding the THP into the swap cache.  This will
reduce lock acquiring/releasing for the locks used for the swap cache
management.

With the patchset, the swap out throughput improves 15.5% (from about
3.73GB/s to about 4.31GB/s) in the vm-scalability swap-w-seq test case
with 8 processes.  The test is done on a Xeon E5 v3 system.  The swap
device used is a RAM simulated PMEM (persistent memory) device.  To test
the sequential swapping out, the test case creates 8 processes, which
sequentially allocate and write to the anonymous pages until the RAM and
part of the swap device is used up.

This patch (of 5):

In this patch, splitting huge page is delayed from almost the first step
of swapping out to after allocating the swap space for the THP
(Transparent Huge Page) and adding the THP into the swap cache.  This
will batch the corresponding operation, thus improve THP swap out
throughput.

This is the first step for the THP swap optimization.  The plan is to
delay splitting the THP step by step and avoid splitting the THP
finally.

In this patch, one swap cluster is used to hold the contents of each THP
swapped out.  So, the size of the swap cluster is changed to that of the
THP (Transparent Huge Page) on x86_64 architecture (512).  For other
architectures which want such THP swap optimization,
ARCH_USES_THP_SWAP_CLUSTER needs to be selected in the Kconfig file for
the architecture.  In effect, this will enlarge swap cluster size by 2
times on x86_64.  Which may make it harder to find a free cluster when
the swap space becomes fragmented.  So that, this may reduce the
continuous swap space allocation and sequential write in theory.  The
performance test in 0day shows no regressions caused by this.

In the future of THP swap optimization, some information of the swapped
out THP (such as compound map count) will be recorded in the
swap_cluster_info data structure.

The mem cgroup swap accounting functions are enhanced to support charge
or uncharge a swap cluster backing a THP as a whole.

The swap cluster allocate/free functions are added to allocate/free a
swap cluster for a THP.  A fair simple algorithm is used for swap
cluster allocation, that is, only the first swap device in priority list
will be tried to allocate the swap cluster.  The function will fail if
the trying is not successful, and the caller will fallback to allocate a
single swap slot instead.  This works good enough for normal cases.  If
the difference of the number of the free swap clusters among multiple
swap devices is significant, it is possible that some THPs are split
earlier than necessary.  For example, this could be caused by big size
difference among multiple swap devices.

The swap cache functions is enhanced to support add/delete THP to/from
the swap cache as a set of (HPAGE_PMD_NR) sub-pages.  This may be
enhanced in the future with multi-order radix tree.  But because we will
split the THP soon during swapping out, that optimization doesn't make
much sense for this first step.

The THP splitting functions are enhanced to support to split THP in swap
cache during swapping out.  The page lock will be held during allocating
the swap cluster, adding the THP into the swap cache and splitting the
THP.  So in the code path other than swapping out, if the THP need to be
split, the PageSwapCache(THP) will be always false.

The swap cluster is only available for SSD, so the THP swap optimization
in this patchset has no effect for HDD.

[ying.huang@intel.com: fix two issues in THP optimize patch]
  Link: http://lkml.kernel.org/r/87k25ed8zo.fsf@yhuang-dev.intel.com
[hannes@cmpxchg.org: extensive cleanups and simplifications, reduce code size]
Link: http://lkml.kernel.org/r/20170515112522.32457-2-ying.huang@intel.comSigned-off-by: N"Huang, Ying" <ying.huang@intel.com>
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Suggested-by: Andrew Morton <akpm@linux-foundation.org> [for config option]
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> [for changes in huge_memory.c and huge_mm.h]
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      38d8b4e6
  3. 01 7月, 2017 1 次提交
  5. 30 6月, 2017 10 次提交
  7. 29 6月, 2017 5 次提交
  9. 27 6月, 2017 3 次提交
    • A
      x86/insn: perf tools: Add new ptwrite instruction · d5b1a5f6
      由 Adrian Hunter 提交于 
      Add ptwrite to the op code map and the perf tools new instructions test.
To run the test:

  $ tools/perf/perf test "x86 ins"
  39: Test x86 instruction decoder - new instructions          : Ok

Or to see the details:

  $ tools/perf/perf test -v "x86 ins" 2>&1 | grep ptwrite

For information about ptwrite, refer the Intel SDM.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/1495180230-19367-1-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      d5b1a5f6
    • Y
      x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD systems · 5209654a
      由 Yazen Ghannam 提交于 
      AMD systems support the Monitor/Mwait instructions and these can be used
for ACPI C1 in the same way as on Intel systems.

Three things are needed:
 1) This patch.
 2) BIOS that declares a C1 state in _CST to use FFH, with correct values.
 3) CPUID_Fn00000005_EDX is non-zero on the system.

The BIOS on AMD systems have historically not defined a C1 state in _CST,
so the acpi_idle driver uses HALT for ACPI C1.

Currently released systems have CPUID_Fn00000005_EDX as reserved/RAZ. If a
BIOS is released for these systems that requests a C1 state with FFH, the
FFH implementation in Linux will fail since CPUID_Fn00000005_EDX is 0. The
acpi_idle driver will then fallback to using HALT for ACPI C1.

Future systems are expected to have non-zero CPUID_Fn00000005_EDX and BIOS
support for using FFH for ACPI C1.

Allow ffh_cstate_init() to succeed on AMD systems.

Tested on Fam15h and Fam17h systems.
Signed-off-by: NYazen Ghannam <yazen.ghannam@amd.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      5209654a
    • L
      x86: use common aperfmperf_khz_on_cpu() to calculate KHz using APERF/MPERF · f8475cef
      由 Len Brown 提交于 
      The goal of this change is to give users a uniform and meaningful
result when they read /sys/...cpufreq/scaling_cur_freq
on modern x86 hardware, as compared to what they get today.

Modern x86 processors include the hardware needed
to accurately calculate frequency over an interval --
APERF, MPERF, and the TSC.

Here we provide an x86 routine to make this calculation
on supported hardware, and use it in preference to any
driver driver-specific cpufreq_driver.get() routine.

MHz is computed like so:

MHz = base_MHz * delta_APERF / delta_MPERF

MHz is the average frequency of the busy processor
over a measurement interval.  The interval is
defined to be the time between successive invocations
of aperfmperf_khz_on_cpu(), which are expected to to
happen on-demand when users read sysfs attribute
cpufreq/scaling_cur_freq.

As with previous methods of calculating MHz,
idle time is excluded.

base_MHz above is from TSC calibration global "cpu_khz".

This x86 native method to calculate MHz returns a meaningful result
no matter if P-states are controlled by hardware or firmware
and/or if the Linux cpufreq sub-system is or is-not installed.

When this routine is invoked more frequently, the measurement
interval becomes shorter.  However, the code limits re-computation
to 10ms intervals so that average frequency remains meaningful.

Discerning users are encouraged to take advantage of
the turbostat(8) utility, which can gracefully handle
concurrent measurement intervals of arbitrary length.
Signed-off-by: NLen Brown <len.brown@intel.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      f8475cef
  11. 26 6月, 2017 3 次提交
  13. 24 6月, 2017 5 次提交
    • A
      x86/paravirt: Remove unnecessary return from void function · e8ad8bc4
      由 Anton Vasilyev 提交于 
      The patch removes unnecessary return from void function.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: NAnton Vasilyev <vasilyev@ispras.ru>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: ldv-project@linuxtesting.org
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/1498234993-1320-1-git-send-email-vasilyev@ispras.ruSigned-off-by: NIngo Molnar <mingo@kernel.org>
      e8ad8bc4
    • T
      x86/boot: Add missing strchr() declaration · 6ec829a9
      由 Tommy Nguyen 提交于 
      The Sparse static analyzer emits this warning:

    symbol 'strchr' was not declared. Should it be static?

This patch adds the appropriate extern declaration to string.h
to fix the warning.
Signed-off-by: NTommy Nguyen <remyabel@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170623143601.GA20743@NoChinaSigned-off-by: NIngo Molnar <mingo@kernel.org>
      6ec829a9
    • T
      x86/mshyperv: Remove excess #includes from mshyperv.h · 26fcd952
      由 Thomas Gleixner 提交于 
      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: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NThomas 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: dee863b5 ("hv: export current Hyper-V clocksource")
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1706231038460.2647@nanosSigned-off-by: NIngo Molnar <mingo@kernel.org>
      26fcd952
    • M
      x86/mmap, ASLR: Do not treat unlimited-stack tasks as legacy mmap · 4a06370b
      由 Michal Hocko 提交于 
      Since the following commit in 2008:

  cc503c1b ("x86: PIE executable randomization")

We added a heuristics to treat applications with RLIMIT_STACK configured
to unlimited as legacy. This means:

 a) set the mmap_base to 1/3 of address space + randomization and
 b) mmap from bottom to top.

This makes some sense as it allows the stack to grow really large. On the
other hand it reduces the address space usable for default mmaps
(without address hint) quite a lot.

We have received a bug report that SAP HANA workload has hit into this
limitation.

We could argue that the user just got what he asked for when setting
up the unlimited stack but to be realistic growing stack up to 1/6
TASK_SIZE (allowed by mmap_base) is pretty much unimited in the real
life. This would give mmap 20TB of additional address space which is
quite nice. Especially when it is much more likely to use that address
space than the reserved stack.

Digging into the history the original implementation of the randomization:

  8817210d ("[PATCH] x86_64: Flexmap for 32bit and randomized mappings for 64bit")

didn't have this restriction.

So let's try and remove this assumption - hopefully nothing breaks.
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJiri Kosina <jkosina@suse.cz>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: hughd@google.com
Cc: linux-mm@kvack.org
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/tip-86b110d2ae6365ce91cabd37588bc8611770421a@git.kernel.org
[ So I've applied this to tip:x86/mm with a wider Cc: list - if anyone objects to this change please holler. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      4a06370b
    • L
      x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz" · 51204e06
      由 Len Brown 提交于 
      cpufreq_quick_get() allows cpufreq drivers to over-ride cpu_khz
that is otherwise reported in x86 /proc/cpuinfo "cpu MHz".

There are four problems with this scheme,
any of them is sufficient justification to delete it.

 1. Depending on which cpufreq driver is loaded, the behavior
    of this field is different.

 2. Distros complain that they have to explain to users
    why and how this field changes.  Distros have requested a constant.

 3. The two major providers of this information, acpi_cpufreq
    and intel_pstate, both "get it wrong" in different ways.

    acpi_cpufreq lies to the user by telling them that
    they are running at whatever frequency was last
    requested by software.

    intel_pstate lies to the user by telling them that
    they are running at the average frequency computed
    over an undefined measurement.  But an average computed
    over an undefined interval, is itself, undefined...

 4. On modern processors, user space utilities, such as
    turbostat(1), are more accurate and more precise, while
    supporing concurrent measurement over arbitrary intervals.

Users who have been consulting /proc/cpuinfo to
track changing CPU frequency will be dissapointed that
it no longer wiggles -- perhaps being unaware of the
limitations of the information they have been consuming.

Yes, they can change their scripts to look in sysfs
cpufreq/scaling_cur_frequency.  Here they will find the same
data of dubious quality here removed from /proc/cpuinfo.
The value in sysfs will be addressed in a subsequent patch
to address issues 1-3, above.

Issue 4 will remain -- users that really care about
accurate frequency information should not be using either
proc or sysfs kernel interfaces.
They should be using using turbostat(8), or a similar
purpose-built analysis tool.
Signed-off-by: NLen Brown <len.brown@intel.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
      51204e06
  15. 23 6月, 2017 8 次提交