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If SMAP support is not compiled into the kernel, don't enable SMAP in
CR4 -- in fact, we should clear it, because the kernel doesn't contain
the proper STAC/CLAC instructions for SMAP support.
Found by Fengguang Wu's test system.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.7+
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* Avoid WARN_ON() when mapping BGRT on Baytrail (EFI 32-bit).
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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For additional coverage, BorisO and friends unknowlingly did swap AMD
microcode with Intel microcode blobs in order to see what happens. What
did happen on 32-bit was
[ 5.722656] BUG: unable to handle kernel paging request at be3a6008
[ 5.722693] IP: [<c106d6b4>] load_microcode_amd+0x24/0x3f0
[ 5.722716] *pdpt = 0000000000000000 *pde = 0000000000000000
because there was a valid initrd there but without valid microcode in it
and the container check happened *after* the relocated ramdisk handling
on 32-bit, which was clearly wrong.
While at it, take care of the ramdisk relocation on both 32- and 64-bit
as it is done on both. Also, comment what we're doing because this code
is a bit tricky.
Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1391460104-7261-1-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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Merge in the x86 changes to apply a fix.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There was a large ebizzy performance regression that was
bisected to commit 611ae8e3 (x86/tlb: enable tlb flush range
support for x86). The problem was related to the
tlb_flushall_shift tuning for IvyBridge which was altered. The
problem is that it is not clear if the tuning values for each
CPU family is correct as the methodology used to tune the values
is unclear.
This patch uses a conservative tlb_flushall_shift value for all
CPU families except IvyBridge so the decision can be revisited
if any regression is found as a result of this change.
IvyBridge is an exception as testing with one methodology
determined that the value of 2 is acceptable. Details are in
the changelog for the patch "x86: mm: Change tlb_flushall_shift
for IvyBridge".
One important aspect of this to watch out for is Xen. The
original commit log mentioned large performance gains on Xen.
It's possible Xen is more sensitive to this value if it flushes
small ranges of pages more frequently than workloads on bare
metal typically do.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-dyzMww3fqugnhbhgo6Gxmtkw@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There was a large performance regression that was bisected to
commit 611ae8e3 ("x86/tlb: enable tlb flush range support for
x86"). This patch simply changes the default balance point
between a local and global flush for IvyBridge.
In the interest of allowing the tests to be reproduced, this
patch was tested using mmtests 0.15 with the following
configurations
configs/config-global-dhp__tlbflush-performance
configs/config-global-dhp__scheduler-performance
configs/config-global-dhp__network-performance
Results are from two machines
Ivybridge 4 threads: Intel(R) Core(TM) i3-3240 CPU @ 3.40GHz
Ivybridge 8 threads: Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
Page fault microbenchmark showed nothing interesting.
Ebizzy was configured to run multiple iterations and threads.
Thread counts ranged from 1 to NR_CPUS*2. For each thread count,
it ran 100 iterations and each iteration lasted 10 seconds.
Ivybridge 4 threads
3.13.0-rc7 3.13.0-rc7
vanilla altshift-v3
Mean 1 6395.44 ( 0.00%) 6789.09 ( 6.16%)
Mean 2 7012.85 ( 0.00%) 8052.16 ( 14.82%)
Mean 3 6403.04 ( 0.00%) 6973.74 ( 8.91%)
Mean 4 6135.32 ( 0.00%) 6582.33 ( 7.29%)
Mean 5 6095.69 ( 0.00%) 6526.68 ( 7.07%)
Mean 6 6114.33 ( 0.00%) 6416.64 ( 4.94%)
Mean 7 6085.10 ( 0.00%) 6448.51 ( 5.97%)
Mean 8 6120.62 ( 0.00%) 6462.97 ( 5.59%)
Ivybridge 8 threads
3.13.0-rc7 3.13.0-rc7
vanilla altshift-v3
Mean 1 7336.65 ( 0.00%) 7787.02 ( 6.14%)
Mean 2 8218.41 ( 0.00%) 9484.13 ( 15.40%)
Mean 3 7973.62 ( 0.00%) 8922.01 ( 11.89%)
Mean 4 7798.33 ( 0.00%) 8567.03 ( 9.86%)
Mean 5 7158.72 ( 0.00%) 8214.23 ( 14.74%)
Mean 6 6852.27 ( 0.00%) 7952.45 ( 16.06%)
Mean 7 6774.65 ( 0.00%) 7536.35 ( 11.24%)
Mean 8 6510.50 ( 0.00%) 6894.05 ( 5.89%)
Mean 12 6182.90 ( 0.00%) 6661.29 ( 7.74%)
Mean 16 6100.09 ( 0.00%) 6608.69 ( 8.34%)
Ebizzy hits the worst case scenario for TLB range flushing every
time and it shows for these Ivybridge CPUs at least that the
default choice is a poor on. The patch addresses the problem.
Next was a tlbflush microbenchmark written by Alex Shi at
http://marc.info/?l=linux-kernel&m=133727348217113 . It
measures access costs while the TLB is being flushed. The
expectation is that if there are always full TLB flushes that
the benchmark would suffer and it benefits from range flushing
There are 320 iterations of the test per thread count. The
number of entries is randomly selected with a min of 1 and max
of 512. To ensure a reasonably even spread of entries, the full
range is broken up into 8 sections and a random number selected
within that section.
iteration 1, random number between 0-64
iteration 2, random number between 64-128 etc
This is still a very weak methodology. When you do not know
what are typical ranges, random is a reasonable choice but it
can be easily argued that the opimisation was for smaller ranges
and an even spread is not representative of any workload that
matters. To improve this, we'd need to know the probability
distribution of TLB flush range sizes for a set of workloads
that are considered "common", build a synthetic trace and feed
that into this benchmark. Even that is not perfect because it
would not account for the time between flushes but there are
limits of what can be reasonably done and still be doing
something useful. If a representative synthetic trace is
provided then this benchmark could be revisited and the shift values retuned.
Ivybridge 4 threads
3.13.0-rc7 3.13.0-rc7
vanilla altshift-v3
Mean 1 10.50 ( 0.00%) 10.50 ( 0.03%)
Mean 2 17.59 ( 0.00%) 17.18 ( 2.34%)
Mean 3 22.98 ( 0.00%) 21.74 ( 5.41%)
Mean 5 47.13 ( 0.00%) 46.23 ( 1.92%)
Mean 8 43.30 ( 0.00%) 42.56 ( 1.72%)
Ivybridge 8 threads
3.13.0-rc7 3.13.0-rc7
vanilla altshift-v3
Mean 1 9.45 ( 0.00%) 9.36 ( 0.93%)
Mean 2 9.37 ( 0.00%) 9.70 ( -3.54%)
Mean 3 9.36 ( 0.00%) 9.29 ( 0.70%)
Mean 5 14.49 ( 0.00%) 15.04 ( -3.75%)
Mean 8 41.08 ( 0.00%) 38.73 ( 5.71%)
Mean 13 32.04 ( 0.00%) 31.24 ( 2.49%)
Mean 16 40.05 ( 0.00%) 39.04 ( 2.51%)
For both CPUs, average access time is reduced which is good as
this is the benchmark that was used to tune the shift values in
the first place albeit it is now known *how* the benchmark was
used.
The scheduler benchmarks were somewhat inconclusive. They
showed gains and losses and makes me reconsider how stable those
benchmarks really are or if something else might be interfering
with the test results recently.
Network benchmarks were inconclusive. Almost all results were
flat except for netperf-udp tests on the 4 thread machine.
These results were unstable and showed large variations between
reboots. It is unknown if this is a recent problems but I've
noticed before that netperf-udp results tend to vary.
Based on these results, changing the default for Ivybridge seems
like a logical choice.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Alex Shi <alex.shi@linaro.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-cqnadffh1tiqrshthRj3Esge@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Bisection between 3.11 and 3.12 fingered commit 9824cf97 ("mm:
vmstats: tlb flush counters") to cause overhead problems.
The counters are undeniably useful but how often do we really
need to debug TLB flush related issues? It does not justify
taking the penalty everywhere so make it a debugging option.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-XzxjntugxuwpxXhcrxqqh53b@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core / sysfs patches from Greg KH:
"Here's the big driver core and sysfs patch set for 3.14-rc1.
There's a lot of work here moving sysfs logic out into a "kernfs" to
allow other subsystems to also have a virtual filesystem with the same
attributes of sysfs (handle device disconnect, dynamic creation /
removal as needed / unneeded, etc)
This is primarily being done for the cgroups filesystem, but the goal
is to also move debugfs to it when it is ready, solving all of the
known issues in that filesystem as well. The code isn't completed
yet, but all should be stable now (there is a big section that was
reverted due to problems found when testing)
There's also some other smaller fixes, and a driver core addition that
allows for a "collection" of objects, that the DRM people will be
using soon (it's in this tree to make merges after -rc1 easier)
All of this has been in linux-next with no reported issues"
* tag 'driver-core-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (113 commits)
kernfs: associate a new kernfs_node with its parent on creation
kernfs: add struct dentry declaration in kernfs.h
kernfs: fix get_active failure handling in kernfs_seq_*()
Revert "kernfs: fix get_active failure handling in kernfs_seq_*()"
Revert "kernfs: replace kernfs_node->u.completion with kernfs_root->deactivate_waitq"
Revert "kernfs: remove KERNFS_ACTIVE_REF and add kernfs_lockdep()"
Revert "kernfs: remove KERNFS_REMOVED"
Revert "kernfs: restructure removal path to fix possible premature return"
Revert "kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()"
Revert "kernfs: remove kernfs_addrm_cxt"
Revert "kernfs: make kernfs_get_active() block if the node is deactivated but not removed"
Revert "kernfs: implement kernfs_{de|re}activate[_self]()"
Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers"
Revert "pci: use device_remove_file_self() instead of device_schedule_callback()"
Revert "scsi: use device_remove_file_self() instead of device_schedule_callback()"
Revert "s390: use device_remove_file_self() instead of device_schedule_callback()"
Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
Revert "kernfs: remove unnecessary NULL check in __kernfs_remove()"
kernfs: remove unnecessary NULL check in __kernfs_remove()
drivers/base: provide an infrastructure for componentised subsystems
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 kernel address space randomization support from Peter Anvin:
"This enables kernel address space randomization for x86"
* 'x86-kaslr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, kaslr: Clarify RANDOMIZE_BASE_MAX_OFFSET
x86, kaslr: Remove unused including <linux/version.h>
x86, kaslr: Use char array to gain sizeof sanity
x86, kaslr: Add a circular multiply for better bit diffusion
x86, kaslr: Mix entropy sources together as needed
x86/relocs: Add percpu fixup for GNU ld 2.23
x86, boot: Rename get_flags() and check_flags() to *_cpuflags()
x86, kaslr: Raise the maximum virtual address to -1 GiB on x86_64
x86, kaslr: Report kernel offset on panic
x86, kaslr: Select random position from e820 maps
x86, kaslr: Provide randomness functions
x86, kaslr: Return location from decompress_kernel
x86, boot: Move CPU flags out of cpucheck
x86, relocs: Add more per-cpu gold special cases
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull leftover x86 fixes from Ingo Molnar:
"Two leftover fixes that did not make it into v3.13"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Add check for number of available vectors before CPU down
x86, cpu, amd: Add workaround for family 16h, erratum 793
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 RAS changes from Ingo Molnar:
- SCI reporting for other error types not only correctable ones
- GHES cleanups
- Add the functionality to override error reporting agents as some
machines are sporting a new extended error logging capability which,
if done properly in the BIOS, makes a corresponding EDAC module
redundant
- PCIe AER tracepoint severity levels fix
- Error path correction for the mce device init
- MCE timer fix
- Add more flexibility to the error injection (EINJ) debugfs interface
* 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, mce: Fix mce_start_timer semantics
ACPI, APEI, GHES: Cleanup ghes memory error handling
ACPI, APEI: Cleanup alignment-aware accesses
ACPI, APEI, GHES: Do not report only correctable errors with SCI
ACPI, APEI, EINJ: Changes to the ACPI/APEI/EINJ debugfs interface
ACPI, eMCA: Combine eMCA/EDAC event reporting priority
EDAC, sb_edac: Modify H/W event reporting policy
EDAC: Add an edac_report parameter to EDAC
PCI, AER: Fix severity usage in aer trace event
x86, mce: Call put_device on device_register failure
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 microcode loader updates from Ingo Molnar:
"There are two main changes in this tree:
- AMD microcode early loading fixes
- some microcode loader source files reorganization"
* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, microcode: Move to a proper location
x86, microcode, AMD: Fix early ucode loading
x86, microcode: Share native MSR accessing variants
x86, ramdisk: Export relocated ramdisk VA
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 TLB detection update from Ingo Molnar:
"A single change that extends our TLB cache size detection+reporting
code"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, cpu: Detect more TLB configuration
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Ingo Molnar:
"Misc cleanups"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, cpu, amd: Fix a shadowed variable situation
um, x86: Fix vDSO build
x86: Delete non-required instances of include <linux/init.h>
x86, realmode: Pointer walk cleanups, pull out invariant use of __pa()
x86/traps: Clean up error exception handler definitions
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
- Add the initial implementation of SCHED_DEADLINE support: a real-time
scheduling policy where tasks that meet their deadlines and
periodically execute their instances in less than their runtime quota
see real-time scheduling and won't miss any of their deadlines.
Tasks that go over their quota get delayed (Available to privileged
users for now)
- Clean up and fix preempt_enable_no_resched() abuse all around the
tree
- Do sched_clock() performance optimizations on x86 and elsewhere
- Fix and improve auto-NUMA balancing
- Fix and clean up the idle loop
- Apply various cleanups and fixes
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
sched: Fix __sched_setscheduler() nice test
sched: Move SCHED_RESET_ON_FORK into attr::sched_flags
sched: Fix up attr::sched_priority warning
sched: Fix up scheduler syscall LTP fails
sched: Preserve the nice level over sched_setscheduler() and sched_setparam() calls
sched/core: Fix htmldocs warnings
sched/deadline: No need to check p if dl_se is valid
sched/deadline: Remove unused variables
sched/deadline: Fix sparse static warnings
m68k: Fix build warning in mac_via.h
sched, thermal: Clean up preempt_enable_no_resched() abuse
sched, net: Fixup busy_loop_us_clock()
sched, net: Clean up preempt_enable_no_resched() abuse
sched/preempt: Fix up missed PREEMPT_NEED_RESCHED folding
sched/preempt, locking: Rework local_bh_{dis,en}able()
sched/clock, x86: Avoid a runtime condition in native_sched_clock()
sched/clock: Fix up clear_sched_clock_stable()
sched/clock, x86: Use a static_key for sched_clock_stable
sched/clock: Remove local_irq_disable() from the clocks
sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQs
...
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Pick up the latest fixes, refresh the development tree.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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On AMD family 10h we see following error messages while waking up from
S3 for all non-boot CPUs leading to a failed IBS initialization:
Enabling non-boot CPUs ...
smpboot: Booting Node 0 Processor 1 APIC 0x1
[Firmware Bug]: cpu 1, try to use APIC500 (LVT offset 0) for vector 0x400, but the register is already in use for vector 0xf9 on another cpu
perf: IBS APIC setup failed on cpu #1
process: Switch to broadcast mode on CPU1
CPU1 is up
...
ACPI: Waking up from system sleep state S3
Reason for this is that during suspend the LVT offset for the IBS
vector gets lost and needs to be reinialized while resuming.
The offset is read from the IBSCTL msr. On family 10h the offset needs
to be 1 as offset 0 is used for the MCE threshold interrupt, but
firmware assings it for IBS to 0 too. The kernel needs to reprogram
the vector. The msr is a readonly node msr, but a new value can be
written via pci config space access. The reinitialization is
implemented for family 10h in setup_ibs_ctl() which is forced during
IBS setup.
This patch fixes IBS setup after waking up from S3 by adding
resume/supend hooks for the boot cpu which does the offset
reinitialization.
Marking it as stable to let distros pick up this fix.
Signed-off-by: Robert Richter <rric@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org> v3.2..
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1389797849-5565-1-git-send-email-rric.net@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Having u32 and struct cpuinfo_x86 * by the same name is not very smart,
although it was ok in this case due to the limited scope of u32 c and it
being used only once in there.
Fix this.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1389786735-16751-1-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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This adds the workaround for erratum 793 as a precaution in case not
every BIOS implements it. This addresses CVE-2013-6885.
Erratum text:
[Revision Guide for AMD Family 16h Models 00h-0Fh Processors,
document 51810 Rev. 3.04 November 2013]
793 Specific Combination of Writes to Write Combined Memory Types and
Locked Instructions May Cause Core Hang
Description
Under a highly specific and detailed set of internal timing
conditions, a locked instruction may trigger a timing sequence whereby
the write to a write combined memory type is not flushed, causing the
locked instruction to stall indefinitely.
Potential Effect on System
Processor core hang.
Suggested Workaround
BIOS should set MSR
C001_1020[15] = 1b.
Fix Planned
No fix planned
[ hpa: updated description, fixed typo in MSR name ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20140114230711.GS29865@pd.tnic
Tested-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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We've grown a bunch of microcode loader files all prefixed with
"microcode_". They should be under cpu/ because this is strictly
CPU-related functionality so do that and drop the prefix since they're
in their own directory now which gives that prefix. :)
While at it, drop MICROCODE_INTEL_LIB config item and stash the
functionality under CONFIG_MICROCODE_INTEL as it was its only user.
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
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In order to avoid the runtime condition and variable load turn
sched_clock_stable into a static_key.
Also provide a shorter implementation of local_clock() and
cpu_clock(int) when sched_clock_stable==1.
MAINLINE PRE POST
sched_clock_stable: 1 1 1
(cold) sched_clock: 329841 221876 215295
(cold) local_clock: 301773 234692 220773
(warm) sched_clock: 38375 25602 25659
(warm) local_clock: 100371 33265 27242
(warm) rdtsc: 27340 24214 24208
sched_clock_stable: 0 0 0
(cold) sched_clock: 382634 235941 237019
(cold) local_clock: 396890 297017 294819
(warm) sched_clock: 38194 25233 25609
(warm) local_clock: 143452 71234 71232
(warm) rdtsc: 27345 24245 24243
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-eummbdechzz37mwmpags1gjr@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Use a ring-buffer like multi-version object structure which allows
always having a coherent object; we use this to avoid having to
disable IRQs while reading sched_clock() and avoids a problem when
getting an NMI while changing the cyc2ns data.
MAINLINE PRE POST
sched_clock_stable: 1 1 1
(cold) sched_clock: 329841 331312 257223
(cold) local_clock: 301773 310296 309889
(warm) sched_clock: 38375 38247 25280
(warm) local_clock: 100371 102713 85268
(warm) rdtsc: 27340 27289 24247
sched_clock_stable: 0 0 0
(cold) sched_clock: 382634 372706 301224
(cold) local_clock: 396890 399275 399870
(warm) sched_clock: 38194 38124 25630
(warm) local_clock: 143452 148698 129629
(warm) rdtsc: 27345 27365 24307
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-s567in1e5ekq2nlyhn8f987r@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/ras
Pull RAS updates from Borislav Petkov:
" SCI reporting for other error types not only correctable ones
+ APEI GHES cleanups
+ mce timer fix
"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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So mce_start_timer() has a 'cpu' argument which is supposed to mean to
start a timer on that cpu. However, the code currently starts a timer on
the *current* cpu the function runs on and causes the sanity-check in
mce_timer_fn to fire:
WARNING: CPU: 0 PID: 0 at arch/x86/kernel/cpu/mcheck/mce.c:1286 mce_timer_fn
because it is running on the wrong cpu.
This was triggered by Prarit Bhargava <prarit@redhat.com> by offlining
all the cpus in succession.
Then, we were fiddling with the CMCI storm settings when starting the
timer whereas there's no need for that - if there's storm happening
on this newly restarted cpu, we're going to be in normal CMCI mode
initially and then when the CMCI interrupt starts firing, we're going to
go to the polling mode with the timer real soon.
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Prarit Bhargava <prarit@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Reviewed-by: Chen, Gong <gong.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1387722156-5511-1-git-send-email-prarit@redhat.com
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This patch adds support for the Intel RAPL energy counter
PP1 (Power Plane 1).
On client processors, it usually corresponds to the
energy consumption of the builtin graphic card. That
is why the sysfs event is called energy-gpu.
New event:
- name: power/energy-gpu/
- code: event=0x4
- unit: 2^-32 Joules
On processors without graphics, this should count 0.
The patch only enables this event on client processors.
Reviewed-by: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: ak@linux.intel.com
Cc: acme@redhat.com
Cc: jolsa@redhat.com
Cc: zheng.z.yan@intel.com
Cc: bp@alien8.de
Cc: vincent.weaver@maine.edu
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389176153-3128-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
[ hpa: undid incorrect removal from arch/x86/kernel/head_32.S ]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1389054026-12947-1-git-send-email-paul.gortmaker@windriver.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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The Intel Software Developer’s Manual covers few more TLB
configurations exposed as CPUID 2 descriptors:
61H Instruction TLB: 4 KByte pages, fully associative, 48 entries
63H Data TLB: 1 GByte pages, 4-way set associative, 4 entries
76H Instruction TLB: 2M/4M pages, fully associative, 8 entries
B5H Instruction TLB: 4KByte pages, 8-way set associative, 64 entries
B6H Instruction TLB: 4KByte pages, 8-way set associative, 128 entries
C1H Shared 2nd-Level TLB: 4 KByte/2MByte pages, 8-way associative, 1024 entries
C2H DTLB DTLB: 2 MByte/$MByte pages, 4-way associative, 16 entries
Let's detect them as well.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: http://lkml.kernel.org/r/1387801018-14499-1-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Peter Anvin:
"There is a small EFI fix and a big power regression fix in this batch.
My queue also had a fix for downing a CPU when there are insufficient
number of IRQ vectors available, but I'm holding that one for now due
to recent bug reports"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/efi: Don't select EFI from certain special ACPI drivers
x86 idle: Repair large-server 50-watt idle-power regression
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Currently SCI is employed to handle corrected errors - memory corrected
errors, more specifically but in fact SCI still can be used to handle
any errors, e.g. uncorrected or even fatal ones if enabled by the BIOS.
Enable logging for those kinds of errors too.
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1385363701-12387-1-git-send-email-gong.chen@linux.intel.com
[ Boris: massage commit message, rename function arg. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
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Linux 3.10 changed the timing of how thread_info->flags is touched:
x86: Use generic idle loop
(7d1a941731fabf27e5fb6edbebb79fe856edb4e5)
This caused Intel NHM-EX and WSM-EX servers to experience a large number
of immediate MONITOR/MWAIT break wakeups, which caused cpuidle to demote
from deep C-states to shallow C-states, which caused these platforms
to experience a significant increase in idle power.
Note that this issue was already present before the commit above,
however, it wasn't seen often enough to be noticed in power measurements.
Here we extend an errata workaround from the Core2 EX "Dunnington"
to extend to NHM-EX and WSM-EX, to prevent these immediate
returns from MWAIT, reducing idle power on these platforms.
While only acpi_idle ran on Dunnington, intel_idle
may also run on these two newer systems.
As of today, there are no other models that are known
to need this tweak.
Link: http://lkml.kernel.org/r/CAJvTdK=%2BaNN66mYpCGgbHGCHhYQAKx-vB0kJSWjVpsNb_hOAtQ@mail.gmail.com
Signed-off-by: Len Brown <len.brown@intel.com>
Link: http://lkml.kernel.org/r/baff264285f6e585df757d58b17788feabc68918.1387403066.git.len.brown@intel.com
Cc: <stable@vger.kernel.org> # 3.12.x, 3.11.x, 3.10.x
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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Enable RAPL support for Haswell Celeron (model 69).
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: ak@linux.intel.com
Cc: acme@redhat.com
Cc: jolsa@redhat.com
Cc: zheng.z.yan@intel.com
Cc: bp@alien8.de
Cc: vincent.weaver@maine.edu
Cc: maria.n.dimakopoulou@gmail.com
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1387225224-27799-2-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The EVENT_CONSTRAINT_END() macro defines the end marker as
a constraint with a weight of zero. This was all fine
until we blacklisted the corrupting memory events on
Intel IvyBridge. These events are blacklisted by using
a counter bitmask of zero. Thus, they also get a constraint
weight of zero.
The iteration macro: for_each_constraint tests the weight==0.
Therefore, it was stopping at the first blacklisted event, i.e.,
0xd0. The corrupting events were therefore considered as
unconstrained and were scheduled on any of the generic counters.
This patch fixes the end marker to have a weight of -1. With
this, the blacklisted events get an empty constraint and cannot
be scheduled which is what we want for now.
Signed-off-by: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: ak@linux.intel.com
Cc: jolsa@redhat.com
Cc: zheng.z.yan@intel.com
Link: http://lkml.kernel.org/r/20131204232437.GA10689@starlight
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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|
This patch adds a call to put_device() when the device_register() call
has failed. This is required so that the last reference to the device is
given up.
Signed-off-by: Levente Kurusa <levex@linux.com>
Link: http://lkml.kernel.org/r/5298F900.9000208@linux.com
Signed-off-by: Borislav Petkov <bp@suse.de>
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The RAPL PMU counters do not interrupt on overflow.
Therefore, the kernel needs to poll the counters
to avoid missing an overflow. This patch adds
the hrtimer code to do this.
The timer interval is calculated at boot time
based on the power unit used by the HW.
There is one hrtimer per-cpu to handle the case
of multiple simultaneous use across cores on
the same package + hotplug CPU.
Thanks to Maria Dimakopoulou for her contributions
to this patch especially on the math aspects.
Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
[ Applied 32-bit build fix. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: acme@redhat.com
Cc: jolsa@redhat.com
Cc: zheng.z.yan@intel.com
Cc: bp@alien8.de
Cc: maria.n.dimakopoulou@gmail.com
Link: http://lkml.kernel.org/r/1384275531-10892-5-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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|
This patch adds a new uncore PMU to expose the Intel
RAPL energy consumption counters. Up to 3 counters,
each counting a particular RAPL event are exposed.
The RAPL counters are available on Intel SandyBridge,
IvyBridge, Haswell. The server skus add a 3rd counter.
The following events are available and exposed in sysfs:
- power/energy-cores: power consumption of all cores on socket
- power/energy-pkg: power consumption of all cores + LLc cache
- power/energy-dram: power consumption of DRAM (servers only)
For each event both the unit (Joules) and scale (2^-32 J)
is exposed in sysfs for use by perf stat and other tools.
The files are:
/sys/devices/power/events/energy-*.unit
/sys/devices/power/events/energy-*.scale
The RAPL PMU is uncore by nature and is implemented such
that it only works in system-wide mode. Measuring only
one CPU per socket is sufficient. The /sys/devices/power/cpumask
file can be used by tools to figure out which CPUs to monitor
by default. For instance, on a 2-socket system, 2 CPUs
(one on each socket) will be shown.
All the counters measure in the same unit (exposed via sysfs).
The perf_events API exposes all RAPL counters as 64-bit integers
counting in unit of 1/2^32 Joules (about 0.23 nJ). User level tools
must convert the counts by multiplying them by 2^-32 to obtain
Joules. The reason for this is that the kernel avoids
doing floating point math whenever possible because it is
expensive (user floating-point state must be saved). The method
used avoids kernel floating-point usage. There is no loss of
precision. Thanks to PeterZ for suggesting this approach.
To convert the raw count in Watt:
W = C * 2.3 / (1e10 * time)
or ldexp(C, -32).
RAPL PMU is a new standalone PMU which registers with the
perf_event core subsystem. The PMU type (attr->type) is
dynamically allocated and is available from /sys/device/power/type.
Sampling is not supported by the RAPL PMU. There is no
privilege level filtering either.
Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: acme@redhat.com
Cc: jolsa@redhat.com
Cc: zheng.z.yan@intel.com
Cc: bp@alien8.de
Link: http://lkml.kernel.org/r/1384275531-10892-4-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
"Usual earth-shaking, news-breaking, rocket science pile from
trivial.git"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits)
doc: usb: Fix typo in Documentation/usb/gadget_configs.txt
doc: add missing files to timers/00-INDEX
timekeeping: Fix some trivial typos in comments
mm: Fix some trivial typos in comments
irq: Fix some trivial typos in comments
NUMA: fix typos in Kconfig help text
mm: update 00-INDEX
doc: Documentation/DMA-attributes.txt fix typo
DRM: comment: `halve' -> `half'
Docs: Kconfig: `devlopers' -> `developers'
doc: typo on word accounting in kprobes.c in mutliple architectures
treewide: fix "usefull" typo
treewide: fix "distingush" typo
mm/Kconfig: Grammar s/an/a/
kexec: Typo s/the/then/
Documentation/kvm: Update cpuid documentation for steal time and pv eoi
treewide: Fix common typo in "identify"
__page_to_pfn: Fix typo in comment
Correct some typos for word frequency
clk: fixed-factor: Fix a trivial typo
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 RAS changes from Ingo Molnar:
"The biggest change adds support for Intel 'CPER' (UEFI Common Platform
Error Record) error logging, which builds upon an enhanced error
logging mechanism available on Xeon processors.
Full description is here:
http://www.intel.com/content/www/us/en/architecture-and-technology/enhanced-mca-logging-xeon-paper.html
This change provides a module (and support code) to check for an
extended error log and prints extra details about the error on the
console"
* 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
ACPI, x86: Fix extended error log driver to depend on CONFIG_X86_LOCAL_APIC
dmi: Avoid unaligned memory access in save_mem_devices()
Move cper.c from drivers/acpi/apei to drivers/firmware/efi
EDAC, GHES: Update ghes error record info
ACPI, APEI, CPER: Cleanup CPER memory error output format
ACPI, APEI, CPER: Enhance memory reporting capability
ACPI, APEI, CPER: Add UEFI 2.4 support for memory error
DMI: Parse memory device (type 17) in SMBIOS
ACPI, x86: Extended error log driver for x86 platform
bitops: Introduce a more generic BITMASK macro
ACPI, CPER: Update cper info
ACPI, APEI, CPER: Fix status check during error printing
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/hyperv changes from Ingo Molnar:
"These changes enable Linux guests to boot as 'Modern VM' guest kernels
on MS-Hyperv hosts"
* 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, hyperv: Move a variable to avoid an unused variable warning
x86, hyperv: Fix build error due to missing <asm/apic.h> include
x86, hyperv: Correctly guard the local APIC calibration code
x86, hyperv: Get the local APIC timer frequency from the hypervisor
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu changes from Ingo Molnar:
"The biggest change that stands out is the increase of the
CONFIG_NR_CPUS range from 4096 to 8192 - as real hardware out there
already went beyond 4k CPUs ...
We only allow more than 512 CPUs if offstack cpumasks are enabled.
CONFIG_MAXSMP=y remains to be the 'you are nuts!' extreme testcase,
which now means a max of 8192 CPUs"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Increase max CPU count to 8192
x86/cpu: Allow higher NR_CPUS values
x86/cpu: Always print SMP information in /proc/cpuinfo
x86/cpu: Track legacy CPU model data only on 32-bit kernels
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
"The main changes in this cycle are:
- (much) improved CONFIG_NUMA_BALANCING support from Mel Gorman, Rik
van Riel, Peter Zijlstra et al. Yay!
- optimize preemption counter handling: merge the NEED_RESCHED flag
into the preempt_count variable, by Peter Zijlstra.
- wait.h fixes and code reorganization from Peter Zijlstra
- cfs_bandwidth fixes from Ben Segall
- SMP load-balancer cleanups from Peter Zijstra
- idle balancer improvements from Jason Low
- other fixes and cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED
stop_machine: Fix race between stop_two_cpus() and stop_cpus()
sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus
sched: Fix asymmetric scheduling for POWER7
sched: Move completion code from core.c to completion.c
sched: Move wait code from core.c to wait.c
sched: Move wait.c into kernel/sched/
sched/wait: Fix __wait_event_interruptible_lock_irq_timeout()
sched: Avoid throttle_cfs_rq() racing with period_timer stopping
sched: Guarantee new group-entities always have weight
sched: Fix hrtimer_cancel()/rq->lock deadlock
sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining
sched: Fix race on toggling cfs_bandwidth_used
sched: Remove extra put_online_cpus() inside sched_setaffinity()
sched/rt: Fix task_tick_rt() comment
sched/wait: Fix build breakage
sched/wait: Introduce prepare_to_wait_event()
sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too
sched: Remove get_online_cpus() usage
sched: Fix race in migrate_swap_stop()
...
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The variable hv_lapic_frequency causes an unused variable warning if
CONFIG_X86_LOCAL_APIC is disabled. Since the variable is only used
inside a small if statement, move the declaration of that variable
into the if statement itself.
Cc: K. Y. Srinivasan <kys@microsoft.com>
Link: http://lkml.kernel.org/r/1381444224-3303-1-git-send-email-kys@microsoft.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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Unlike other uncore boxes, IRP boxes live in PCI buses with no UBOX
device. For PCI bus without UBOX device, we find the next bus that
has UBOX device and use its 'bus to socket' mapping.
Besides the counter/control registers in IRP boxes are not properly
aligned.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: eranian@google.com
Cc: "Yan Zheng" <zheng.z.yan@intel.com>
Link: http://lkml.kernel.org/r/1383197815-17706-2-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The encoding for filter registers of IvyBridge-EP uncore QPI boxes is
completely the same as SandyBridge-EP.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: eranian@google.com
Cc: "Yan Zheng" <zheng.z.yan@intel.com>
Link: http://lkml.kernel.org/r/1383197815-17706-1-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The arch_perf_output_copy_user() default of
__copy_from_user_inatomic() returns bytes not copied, while all other
argument functions given DEFINE_OUTPUT_COPY() return bytes copied.
Since copy_from_user_nmi() is the odd duck out by returning bytes
copied where all other *copy_{to,from}* functions return bytes not
copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes
not copied.
Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied
while expecting its worker functions to return bytes copied.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: will.deacon@arm.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131030201622.GR16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Currently show_cpuinfo_core() displays cpu core information only if
the number of threads per a whole cores is 2 or larger.
However, this condition doesn't care about the number of
sockets. For example, this condition doesn't hold on systems
with two logical cpus consisting of two sockets and a single
core on each socket - yet the topology information would be
interesting to see in that case as well.
I don't know whether or not there are processors in real world
by which such configurations are possible, but at least on
vitual machine environments, such configuration can occur,
typically when no explicit SMP information is provided in
advance.
For example, on qemu/KVM, SMP information is specified via -smp
command-line option, more specifically, its syntax is:
-smp n[,cores=cores][,threads=threads][,sockets=sockets][,maxcpus=maxcpus]
If this is not specified, qemu tells configuration with
n-sockets, 1-core and 1-thread to the guest machine, on which
guest, MP information is not displayed in /proc/cpuinfo.
I saw this situation on VMWare guest environment, too.
To fix this issue, this patch simply removes the condition
because this information is useful even if there's only 1
thread.
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/5277D644.4090707@jp.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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|
more changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Conflicts:
tools/perf/bench/numa.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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|
9e7827b5ea4c ("x86, hyperv: Get the local APIC timer frequency from the
hypervisor") breaks the build with some configs because apic.h isn't
directly included:
arch/x86/kernel/cpu/mshyperv.c: In function 'ms_hyperv_init_platform':
arch/x86/kernel/cpu/mshyperv.c:90:3: error: 'lapic_timer_frequency' undeclared (first use in this function)
arch/x86/kernel/cpu/mshyperv.c:90:3: note: each undeclared identifier is reported only once for each function it appears in
Fix it by including asm/apic.h.
Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1310111604160.31170@chino.kir.corp.google.com
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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|
OK, so what I'm actually seeing on my WSM is that sched/clock.c is
'broken' for the purpose we're using it for.
What triggered it is that my WSM-EP is broken :-(
[ 0.001000] tsc: Fast TSC calibration using PIT
[ 0.002000] tsc: Detected 2533.715 MHz processor
[ 0.500180] TSC synchronization [CPU#0 -> CPU#6]:
[ 0.505197] Measured 3 cycles TSC warp between CPUs, turning off TSC clock.
[ 0.004000] tsc: Marking TSC unstable due to check_tsc_sync_source failed
For some reason it consistently detects TSC skew, even though NHM+
should have a single clock domain for 'reasonable' systems.
This marks sched_clock_stable=0, which means that we do fancy stuff to
try and get a 'sane' clock. Part of this fancy stuff relies on the tick,
clearly that's gone when NOHZ=y. So for idle cpus time gets stuck, until
it either wakes up or gets kicked by another cpu.
While this is perfectly fine for the scheduler -- it only cares about
actually running stuff, and when we're running stuff we're obviously not
idle. This does somewhat break down for perf which can trigger events
just fine on an otherwise idle cpu.
So I've got NMIs get get 'measured' as taking ~1ms, which actually
don't last nearly that long:
<idle>-0 [013] d.h. 886.311970: rcu_nmi_enter <-do_nmi
...
<idle>-0 [013] d.h. 886.311997: perf_sample_event_took: HERE!!! : 1040990
So ftrace (which uses sched_clock(), not the fancy bits) only sees
~27us, but we measure ~1ms !!
Now since all this measurement stuff lives in x86 code, we can actually
fix it.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: mingo@kernel.org
Cc: dave.hansen@linux.intel.com
Cc: eranian@google.com
Cc: Don Zickus <dzickus@redhat.com>
Cc: jmario@redhat.com
Cc: acme@infradead.org
Link: http://lkml.kernel.org/r/20131017133350.GG3364@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
