prefill_possible_map() reinitializes the cpu_possible_map by setting the
possible cpu bits and clearing all other bits up to NR_CPUS.
This is technically always correct because cpu_possible_map is statically
allocated and sized NR_CPUS. With CPUMASK_OFFSTACK and DEBUG_PER_CPU_MAPS
enabled the bounds check of cpu masks happens on nr_cpu_ids. nr_cpu_ids is
initialized to NR_CPUS and only limited after the set/clear bit loops have
been executed.
But if the system was booted with "nr_cpus=N" on the command line, where N
is < NR_CPUS then nr_cpu_ids is limited in the parameter parsing function
before prefill_possible_map() is invoked. As a consequence the cpumask
bounds check triggers when clearing the bits past nr_cpu_ids.
Add a helper which allows to reset cpu_possible_map w/o the bounds check
and then set only the possible bits which are well inside bounds.
Reported-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: 0x7f454c46@gmail.com
Cc: Jan Beulich <JBeulich@novell.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1612131836050.3415@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The logical package management has several issues:
- The APIC ids provided by ACPI are not required to be the same as the
initial APIC id which can be retrieved by CPUID. The APIC ids provided
by ACPI are those which are written by the BIOS into the APIC. The
initial id is set by hardware and can not be changed. The hardware
provided ids contain the real hardware package information.
Especially AMD sets the effective APIC id different from the hardware id
as they need to reserve space for the IOAPIC ids starting at id 0.
As a consequence those machines trigger the currently active firmware
bug printouts in dmesg, These are obviously wrong.
- Virtual machines have their own interesting of enumerating APICs and
packages which are not reliably covered by the current implementation.
The sizing of the mapping array has been tweaked to be generously large to
handle systems which provide a wrong core count when HT is disabled so the
whole magic which checks for space in the physical hotplug case is not
needed anymore.
Simplify the whole machinery and do the mapping when the CPU starts and the
CPUID derived physical package information is available. This solves the
observed problems on AMD machines and works for the virtualization issues
as well.
Remove the extra call from XEN cpu bringup code as it is not longer
required.
Fixes: d49597fd3b ("x86/cpu: Deal with broken firmware (VMWare/XEN)")
Reported-and-tested-by: Borislav Petkov <bp@suse.de>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: M. Vefa Bicakci <m.v.b@runbox.com>
Cc: xen-devel <xen-devel@lists.xen.org>
Cc: Charles (Chas) Williams <ciwillia@brocade.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Alok Kataria <akataria@vmware.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1612121102260.3429@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull irq updates from Thomas Gleixner:
"The irq department provides:
- a major update to the auto affinity management code, which is used
by multi-queue devices
- move of the microblaze irq chip driver into the common driver code
so it can be shared between microblaze, powerpc and MIPS
- a series of updates to the ARM GICV3 interrupt controller
- the usual pile of fixes and small improvements all over the place"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
powerpc/virtex: Use generic xilinx irqchip driver
irqchip/xilinx: Try to fall back if xlnx,kind-of-intr not provided
irqchip/xilinx: Add support for parent intc
irqchip/xilinx: Rename get_irq to xintc_get_irq
irqchip/xilinx: Restructure and use jump label api
irqchip/xilinx: Clean up print messages
microblaze/irqchip: Move intc driver to irqchip
ARM: virt: Select ARM_GIC_V3_ITS
ARM: gic-v3-its: Add 32bit support to GICv3 ITS
irqchip/gic-v3-its: Specialise readq and writeq accesses
irqchip/gic-v3-its: Specialise flush_dcache operation
irqchip/gic-v3-its: Narrow down Entry Size when used as a divider
irqchip/gic-v3-its: Change unsigned types for AArch32 compatibility
irqchip/gic-v3: Use nops macro for Cavium ThunderX erratum 23154
irqchip/gic-v3: Convert arm64 GIC accessors to {read,write}_sysreg_s
genirq/msi: Drop artificial PCI dependency
irqchip/bcm7038-l1: Implement irq_cpu_offline() callback
genirq/affinity: Use default affinity mask for reserved vectors
genirq/affinity: Take reserved vectors into account when spreading irqs
PCI: Remove the irq_affinity mask from struct pci_dev
...
Pull timer updates from Thomas Gleixner:
"The time/timekeeping/timer folks deliver with this update:
- Fix a reintroduced signed/unsigned issue and cleanup the whole
signed/unsigned mess in the timekeeping core so this wont happen
accidentaly again.
- Add a new trace clock based on boot time
- Prevent injection of random sleep times when PM tracing abuses the
RTC for storage
- Make posix timers configurable for real tiny systems
- Add tracepoints for the alarm timer subsystem so timer based
suspend wakeups can be instrumented
- The usual pile of fixes and updates to core and drivers"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
timekeeping: Use mul_u64_u32_shr() instead of open coding it
timekeeping: Get rid of pointless typecasts
timekeeping: Make the conversion call chain consistently unsigned
timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion
alarmtimer: Add tracepoints for alarm timers
trace: Update documentation for mono, mono_raw and boot clock
trace: Add an option for boot clock as trace clock
timekeeping: Add a fast and NMI safe boot clock
timekeeping/clocksource_cyc2ns: Document intended range limitation
timekeeping: Ignore the bogus sleep time if pm_trace is enabled
selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous"
clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap
clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map()
arm64: dts: rockchip: Arch counter doesn't tick in system suspend
clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend
posix-timers: Make them configurable
posix_cpu_timers: Move the add_device_randomness() call to a proper place
timer: Move sys_alarm from timer.c to itimer.c
ptp_clock: Allow for it to be optional
Kconfig: Regenerate *.c_shipped files after previous changes
...
Pull smp hotplug updates from Thomas Gleixner:
"This is the final round of converting the notifier mess to the state
machine. The removal of the notifiers and the related infrastructure
will happen around rc1, as there are conversions outstanding in other
trees.
The whole exercise removed about 2000 lines of code in total and in
course of the conversion several dozen bugs got fixed. The new
mechanism allows to test almost every hotplug step standalone, so
usage sites can exercise all transitions extensively.
There is more room for improvement, like integrating all the
pointlessly different architecture mechanisms of synchronizing,
setting cpus online etc into the core code"
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
tracing/rb: Init the CPU mask on allocation
soc/fsl/qbman: Convert to hotplug state machine
soc/fsl/qbman: Convert to hotplug state machine
zram: Convert to hotplug state machine
KVM/PPC/Book3S HV: Convert to hotplug state machine
arm64/cpuinfo: Convert to hotplug state machine
arm64/cpuinfo: Make hotplug notifier symmetric
mm/compaction: Convert to hotplug state machine
iommu/vt-d: Convert to hotplug state machine
mm/zswap: Convert pool to hotplug state machine
mm/zswap: Convert dst-mem to hotplug state machine
mm/zsmalloc: Convert to hotplug state machine
mm/vmstat: Convert to hotplug state machine
mm/vmstat: Avoid on each online CPU loops
mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()
tracing/rb: Convert to hotplug state machine
oprofile/nmi timer: Convert to hotplug state machine
net/iucv: Use explicit clean up labels in iucv_init()
x86/pci/amd-bus: Convert to hotplug state machine
x86/oprofile/nmi: Convert to hotplug state machine
...
Pull x86 platform updates from Ingo Molnar:
"Two changes:
- implement various VMWare guest OS improvements/fixes (Alexey
Makhalov)
- unexport a spurious export from the intel-mid platform driver
(Lukas Wunner)"
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/vmware: Add paravirt sched clock
x86/vmware: Add basic paravirt ops support
x86/vmware: Use tsc_khz value for calibrate_cpu()
x86/platform/intel-mid: Unexport intel_mid_pci_set_power_state()
x86/vmware: Read tsc_khz only once at boot time
Pull x86 microcode update from Ingo Molnar:
"The biggest change (by Borislav Petkov) is a thorough rewrite of the
Intel microcode loader and its interactions with the core code.
The biggest conceptual change is the decoupling of the microcode
loading on boot and application processors (which load the microcode
in different scenarios), so that both parse the input patches with as
few assumptions as possible - this also fixes various kernel address
space randomization bugs. (The AP side then goes on and caches the
result to improve boot performance.)
Since the AMD side already did this, this change also opened up the
path towards more unification/simplification of the core microcode
loading infrastructure:
10 files changed, 647 insertions(+), 940 deletions(-)
which speaks for itself"
* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode: Bump driver version, update copyrights
x86/microcode: Rework microcode loading
x86/microcode/intel: Remove intel_lib.c
x86/microcode/amd: Move private inlines to .c and mark local functions static
x86/microcode: Collect CPU info on resume
x86/microcode: Issue the debug printk on resume only on success
x86/microcode/amd: Hand down the CPU family
x86/microcode: Export the microcode cache linked list
x86/microcode: Remove one #ifdef clause
x86/microcode/intel: Simplify generic_load_microcode()
x86/microcode: Move driver authors to CREDITS
x86/microcode: Run the AP-loading routine only on the application processors
Pull x86 idle updates from Ingo Molnar:
"There were two bigger changes in this development cycle:
- remove idle notifiers:
32 files changed, 74 insertions(+), 803 deletions(-)
These notifiers were of questionable value and the main usecase,
the i7300 driver, was essentially unmaintained and can be removed,
plus modern power management concepts don't need the callback - so
use this golden opportunity and get rid of this opaque and fragile
callback from a latency sensitive code path.
(Len Brown, Thomas Gleixner)
- improve the AMD Erratum 400 workaround that used high overhead MSR
polling in the idle loop (Borisla Petkov, Thomas Gleixner)"
* 'x86-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Remove empty idle.h header
x86/amd: Simplify AMD E400 aware idle routine
x86/amd: Check for the C1E bug post ACPI subsystem init
x86/bugs: Separate AMD E400 erratum and C1E bug
x86/cpufeature: Provide helper to set bugs bits
x86/idle: Remove enter_idle(), exit_idle()
x86: Remove x86_test_and_clear_bit_percpu()
x86/idle: Remove is_idle flag
x86/idle: Remove idle_notifier
i7300_idle: Remove this driver
Pull x86 header fixlet from Ingo Molnar:
"Remove unnecessary module.h inclusion from core code (Paul Gortmaker)"
* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/percpu: Remove unnecessary include of module.h, add asm/desc.h
Pull x86 FPU updates from Ingo Molnar:
"The main changes in this cycle were:
- do a large round of simplifications after all CPUs do 'eager' FPU
context switching in v4.9: remove CR0 twiddling, remove leftover
eager/lazy bts, etc (Andy Lutomirski)
- more FPU code simplifications: remove struct fpu::counter, clarify
nomenclature, remove unnecessary arguments/functions and better
structure the code (Rik van Riel)"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Remove clts()
x86/fpu: Remove stts()
x86/fpu: Handle #NM without FPU emulation as an error
x86/fpu, lguest: Remove CR0.TS support
x86/fpu, kvm: Remove host CR0.TS manipulation
x86/fpu: Remove irq_ts_save() and irq_ts_restore()
x86/fpu: Stop saving and restoring CR0.TS in fpu__init_check_bugs()
x86/fpu: Get rid of two redundant clts() calls
x86/fpu: Finish excising 'eagerfpu'
x86/fpu: Split old_fpu & new_fpu handling into separate functions
x86/fpu: Remove 'cpu' argument from __cpu_invalidate_fpregs_state()
x86/fpu: Split old & new FPU code paths
x86/fpu: Remove __fpregs_(de)activate()
x86/fpu: Rename lazy restore functions to "register state valid"
x86/fpu, kvm: Remove KVM vcpu->fpu_counter
x86/fpu: Remove struct fpu::counter
x86/fpu: Remove use_eager_fpu()
x86/fpu: Remove the XFEATURE_MASK_EAGER/LAZY distinction
x86/fpu: Hard-disable lazy FPU mode
x86/crypto, x86/fpu: Remove X86_FEATURE_EAGER_FPU #ifdef from the crc32c code
Pull x86 CPU updates from Ingo Molnar:
"The changes in this development cycle were:
- AMD CPU topology enhancements that are cleanups on current CPUs but
which enable future Fam17 hardware. (Yazen Ghannam)
- unify bugs.c and bugs_64.c (Borislav Petkov)
- remove the show_msr= boot option (Borislav Petkov)
- simplify a boot message (Borislav Petkov)"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu/AMD: Clean up cpu_llc_id assignment per topology feature
x86/cpu: Get rid of the show_msr= boot option
x86/cpu: Merge bugs.c and bugs_64.c
x86/cpu: Remove the printk format specifier in "CPU0: "
Pull x86 cleanups from Ingo Molnar:
"Two cleanups in the LDT handling code, by Dan Carpenter and Thomas
Gleixner"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ldt: Make all size computations unsigned
x86/ldt: Make a size argument unsigned
Pull x86 build updates from Ingo Molnar:
"The main changes in this cycle were:
- Makefile improvements (Paul Bolle)
- KConfig cleanups to better separate 32-bit only, 64-bit only and
generic feature enablement sections (Ingo Molnar)"
* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/build: Remove three unneeded genhdr-y entries
x86/build: Don't use $(LINUXINCLUDE) twice
x86/kconfig: Sort the 'config X86' selects alphabetically
x86/kconfig: Clean up 32-bit compat options
x86/kconfig: Clean up IA32_EMULATION select
x86/kconfig, x86/pkeys: Move pkeys selects to X86_INTEL_MEMORY_PROTECTION_KEYS
x86/kconfig: Move 64-bit only arch Kconfig selects to 'config X86_64'
x86/kconfig: Move 32-bit only arch Kconfig selects to 'config X86_32'
Pull x86 boot updates from Ingo Molnar:
"Misc cleanups/simplifications by Borislav Petkov, Paul Bolle and Wei
Yang"
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot/64: Optimize fixmap page fixup
x86/boot: Simplify the GDTR calculation assembly code a bit
x86/boot/build: Remove always empty $(USERINCLUDE)
Pull x86 asm updates from Ingo Molnar:
"The main changes in this development cycle were:
- a large number of call stack dumping/printing improvements: higher
robustness, better cross-context dumping, improved output, etc.
(Josh Poimboeuf)
- vDSO getcpu() performance improvement for future Intel CPUs with
the RDPID instruction (Andy Lutomirski)
- add two new Intel AVX512 features and the CPUID support
infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela,
He Chen)
- more copy-user unification (Borislav Petkov)
- entry code assembly macro simplifications (Alexander Kuleshov)
- vDSO C/R support improvements (Dmitry Safonov)
- misc fixes and cleanups (Borislav Petkov, Paul Bolle)"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
scripts/decode_stacktrace.sh: Fix address line detection on x86
x86/boot/64: Use defines for page size
x86/dumpstack: Make stack name tags more comprehensible
selftests/x86: Add test_vdso to test getcpu()
x86/vdso: Use RDPID in preference to LSL when available
x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl()
x86/cpufeatures: Enable new AVX512 cpu features
x86/cpuid: Provide get_scattered_cpuid_leaf()
x86/cpuid: Cleanup cpuid_regs definitions
x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants
x86/unwind: Ensure stack grows down
x86/vdso: Set vDSO pointer only after success
x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE
x86/unwind: Detect bad stack return address
x86/dumpstack: Warn on stack recursion
x86/unwind: Warn on bad frame pointer
x86/decoder: Use stderr if insn sanity test fails
x86/decoder: Use stdout if insn decoder test is successful
mm/page_alloc: Remove kernel address exposure in free_reserved_area()
x86/dumpstack: Remove raw stack dump
...
Pull x86 apic updates from Ingo Molnar:
"Misc changes:
- optimize (reduce) IRQ handler tracing overhead (Wanpeng Li)
- clean up MSR helpers (Borislav Petkov)
- fix build warning on some configs (Sebastian Andrzej Siewior)"
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/msr: Cleanup/streamline MSR helpers
x86/apic: Prevent tracing on apic_msr_write_eoi()
x86/msr: Add wrmsr_notrace()
x86/apic: Get rid of "warning: 'acpi_ioapic_lock' defined but not used"
Pull x86 RAS updates from Ingo Molnar:
"The main changes in this development cycle were:
- more AMD northbridge support work, mostly in preparation for Fam17h
CPUs (Yazen Ghannam, Borislav Petkov)
- cleanups/refactorings and fixes (Borislav Petkov, Tony Luck,
Yinghai Lu)"
* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Include the PPIN in MCE records when available
x86/mce/AMD: Add system physical address translation for AMD Fam17h
x86/amd_nb: Add SMN and Indirect Data Fabric access for AMD Fam17h
x86/amd_nb: Add Fam17h Data Fabric as "Northbridge"
x86/amd_nb: Make all exports EXPORT_SYMBOL_GPL
x86/amd_nb: Make amd_northbridges internal to amd_nb.c
x86/mce/AMD: Reset Threshold Limit after logging error
x86/mce/AMD: Fix HWID_MCATYPE calculation by grouping arguments
x86/MCE: Correct TSC timestamping of error records
x86/RAS: Hide SMCA bank names
x86/RAS: Rename smca_bank_names to smca_names
x86/RAS: Simplify SMCA HWID descriptor struct
x86/RAS: Simplify SMCA bank descriptor struct
x86/MCE: Dump MCE to dmesg if no consumers
x86/RAS: Add TSC timestamp to the injected MCE
x86/MCE: Do not look at panic_on_oops in the severity grading
Pull hotplug API fix from Ingo Molnar:
"Late breaking fix from the v4.9 cycle: fix a hotplug register/
unregister notifier API asymmetry bug that can cause kernel warnings
(and worse) with certain Kconfig combinations"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hotplug: Make register and unregister notifier API symmetric
Pull scheduler updates from Ingo Molnar:
"The main scheduler changes in this cycle were:
- support Intel Turbo Boost Max Technology 3.0 (TBM3) by introducig a
notion of 'better cores', which the scheduler will prefer to
schedule single threaded workloads on. (Tim Chen, Srinivas
Pandruvada)
- enhance the handling of asymmetric capacity CPUs further (Morten
Rasmussen)
- improve/fix load handling when moving tasks between task groups
(Vincent Guittot)
- simplify and clean up the cputime code (Stanislaw Gruszka)
- improve mass fork()ed task spread a.k.a. hackbench speedup (Vincent
Guittot)
- make struct kthread kmalloc()ed and related fixes (Oleg Nesterov)
- add uaccess atomicity debugging (when using access_ok() in the
wrong context), under CONFIG_DEBUG_ATOMIC_SLEEP=y (Peter Zijlstra)
- implement various fixes, cleanups and other enhancements (Daniel
Bristot de Oliveira, Martin Schwidefsky, Rafael J. Wysocki)"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
sched/core: Use load_avg for selecting idlest group
sched/core: Fix find_idlest_group() for fork
kthread: Don't abuse kthread_create_on_cpu() in __kthread_create_worker()
kthread: Don't use to_live_kthread() in kthread_[un]park()
kthread: Don't use to_live_kthread() in kthread_stop()
Revert "kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function"
kthread: Make struct kthread kmalloc'ed
x86/uaccess, sched/preempt: Verify access_ok() context
sched/x86: Make CONFIG_SCHED_MC_PRIO=y easier to enable
sched/x86: Change CONFIG_SCHED_ITMT to CONFIG_SCHED_MC_PRIO
x86/sched: Use #include <linux/mutex.h> instead of #include <asm/mutex.h>
cpufreq/intel_pstate: Use CPPC to get max performance
acpi/bus: Set _OSC for diverse core support
acpi/bus: Enable HWP CPPC objects
x86/sched: Add SD_ASYM_PACKING flags to x86 ITMT CPU
x86/sysctl: Add sysctl for ITMT scheduling feature
x86: Enable Intel Turbo Boost Max Technology 3.0
x86/topology: Define x86's arch_update_cpu_topology
sched: Extend scheduler's asym packing
sched/fair: Clean up the tunable parameter definitions
...
Pull perf updates from Ingo Molnar:
"This update is pretty big and almost exclusively includes tooling
changes, because v4.9's LTS status forced to completion most of the
pending kernel side hardware enablement work and because we tried to
freeze core perf work a bit to give a time window for the fuzzing
efforts.
The diff is large mostly due to the JSON hardware event tables added
for Intel and Power8 CPUs. This was a popular feature request from
people working close to hardware and from the HPC community.
Tree size is big because this added the CPU event tables for over a
decade of Intel CPUs. Future changes for a CPU vendor alrady support
should be much smaller, as events for new models are added. The new
events are listed in 'perf list', for the CPU model the tool is
running on. If you find an interesting event it can be used as-is:
$ perf stat -a -e l2_lines_out.pf_clean sleep 1
Performance counter stats for 'system wide':
7,860,403 l2_lines_out.pf_clean
1.000624918 seconds time elapsed
The event lists can be searched the usual 'perf list' fashion for
(case insensitive) substrings as well:
$ perf list l2_lines_out
List of pre-defined events (to be used in -e):
cache:
l2_lines_out.demand_clean
[Clean L2 cache lines evicted by demand]
l2_lines_out.demand_dirty
[Dirty L2 cache lines evicted by demand]
l2_lines_out.dirty_all
[Dirty L2 cache lines filling the L2]
l2_lines_out.pf_clean
[Clean L2 cache lines evicted by L2 prefetch]
l2_lines_out.pf_dirty
[Dirty L2 cache lines evicted by L2 prefetch]
etc.
There's a few high level categories as well that can be listed:
'cache', 'floating point', 'frontend', 'memory', 'pipeline', 'virtual
memory'.
Existing generic events and workflows should work as-is.
The only kernel side change is a late breaking fix for an older
regression, related to Intel BTS, LBR and PT feature interaction.
On the tooling side there are three new tools / major features:
- The new 'perf c2c' tool provides means for Shared Data C2C/HITM
analysis.
This allows you to track down cacheline contention. The tool is
based on x86's load latency and precise store facility events
provided by Intel CPUs.
It was tested by Joe Mario and has proven to be useful, finding
some cacheline contentions. Joe also wrote a blog about c2c tool
with examples:
https://joemario.github.io/blog/2016/09/01/c2c-blog/
excerpt of the content on this site:
At a high level, “perf c2c” will show you:
* The cachelines where false sharing was detected.
* The readers and writers to those cachelines, and the offsets where those accesses occurred.
* The pid, tid, instruction addr, function name, binary object name for those readers and writers.
* The source file and line number for each reader and writer.
* The average load latency for the loads to those cachelines.
* Which numa nodes the samples a cacheline came from and which CPUs were involved.
Using perf c2c is similar to using the Linux perf tool today.
First collect data with “perf c2c record”, then generate a
report output with “perf c2c report”
There one finds extensive details on using the tool, with tips on
reducing the volume of samples while still capturing enough to do
its job. (Dick Fowles, Joe Mario, Don Zickus, Jiri Olsa)
- The new 'perf sched timehist' tool provides tailored analysis of
scheduling events.
Example usage:
perf sched record -- sleep 1
perf sched timehist
By default it shows the individual schedule events, including the
wait time (time between sched-out and next sched-in events for the
task), the task scheduling delay (time between wakeup and actually
running) and run time for the task:
time cpu task name wait time sch delay run time
[tid/pid] (msec) (msec) (msec)
-------- ------ ---------------- --------- --------- --------
1.874569 [0011] gcc[31949] 0.014 0.000 1.148
1.874591 [0010] gcc[31951] 0.000 0.000 0.024
1.874603 [0010] migration/10[59] 3.350 0.004 0.011
1.874604 [0011] <idle> 1.148 0.000 0.035
1.874723 [0005] <idle> 0.016 0.000 1.383
1.874746 [0005] gcc[31949] 0.153 0.078 0.022
...
Times are in msec.usec. (David Ahern, Namhyung Kim)
- Add CPU vendor hardware event tables:
Add JSON files with vendor event naming for Intel and Power8
processors, allowing users of tools like oprofile to keep using the
event names they are used to, as well as people reading vendor
documentation, where such naming is used. (Andi Kleen, Sukadev
Bhattiprolu)
You should see all the new events with 'perf list' and you should
be able to search them, for example 'perf list miss' will list all
the myriads of miss events.
Other tooling features added were:
- Cross-arch annotation support:
o Improve ARM support in the annotation code, affecting 'perf
annotate', 'perf report' and live annotation in 'perf top' (Kim
Phillips)
o Initial support for PowerPC in the annotation code (Ravi
Bangoria)
o Support AArch64 in the 'annotate' code, native/local and
cross-arch/remote (Kim Phillips)
- Allow considering just events in a given time interval, via the
'--time start.s.ms,end.s.ms' command line, added to 'perf kmem',
'perf report', 'perf sched timehist' and 'perf script' (David
Ahern)
- Add option to stop printing a callchain at one of a given group of
symbol names (David Ahern)
- Track memory freed in 'perf kmem stat' (David Ahern)
- Allow querying and setting .perfconfig variables (Taeung Song)
- Show branch information in callchains (predicted, TSX aborts, loop
iteractions, etc) (Jin Yao)
- Dynamicly change verbosity level by pressing 'V' in the 'perf
top/report' hists TUI browser (Alexis Berlemont)
- Implement 'perf trace --delay' in the same fashion as in 'perf
record --delay', to skip sampling workload initialization events
(Alexis Berlemont)
- Make vendor named events case insensitive in 'perf list', i.e.
'perf list LONGEST_LAT' works just the same as 'perf list
longest_lat' (Andi Kleen)
- Add unwinding support for jitdump (Stefano Sanfilippo)
Tooling infrastructure changes:
- Support linking perf with clang and LLVM libraries, initially
statically, but this limitation will be lifted and shared
libraries, when available, will be preferred to the static build,
that should, as with other features, be enabled explicitly (Wang
Nan)
- Add initial support (and perf test entry) for tooling hooks,
starting with 'record_start' and 'record_end', that will have as
its initial user the eBPF infrastructure, where perf_ prefixed
functions will be JITed and run when such hooks are called (Wang
Nan)
- Implement assorted libbpf improvements (Wang Nan)"
... and lots of other changes, features, cleanups and refactorings I
did not list, see the shortlog and the git log for details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (220 commits)
perf/x86: Fix exclusion of BTS and LBR for Goldmont
perf tools: Explicitly document that --children is enabled by default
perf sched timehist: Cleanup idle_max_cpu handling
perf sched timehist: Handle zero sample->tid properly
perf callchain: Introduce callchain_cursor__copy()
perf sched: Cleanup option processing
perf sched timehist: Improve error message when analyzing wrong file
perf tools: Move perf build related variables under non fixdep leg
perf tools: Force fixdep compilation at the start of the build
perf tools: Move PERF-VERSION-FILE target into rules area
perf build: Check LLVM version in feature check
perf annotate: Show raw form for jump instruction with indirect target
perf tools: Add non config targets
perf tools: Cleanup build directory before each test
perf tools: Move python/perf.so target into rules area
perf tools: Move install-gtk target into rules area
tools build: Move tabs to spaces where suitable
tools build: Make the .cmd file more readable
perf clang: Compile BPF script using builtin clang support
perf clang: Support compile IR to BPF object and add testcase
...
Pull mm/PAT cleanup from Ingo Molnar:
"A single cleanup for a generic interface that was originally
introduced for PAT"
* 'mm-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/pat, mm: Make track_pfn_insert() return void
Boris Ostrovsky
Thomas Gleixner
Josh Poimboeuf
Linus Torvalds