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2017-02-05x86/CPU/AMD: Bring back Compute Unit IDBorislav Petkov
Commit: a33d331761bc ("x86/CPU/AMD: Fix Bulldozer topology") restored the initial approach we had with the Fam15h topology of enumerating CU (Compute Unit) threads as cores. And this is still correct - they're beefier than HT threads but still have some shared functionality. Our current approach has a problem with the Mad Max Steam game, for example. Yves Dionne reported a certain "choppiness" while playing on v4.9.5. That problem stems most likely from the fact that the CU threads share resources within one CU and when we schedule to a thread of a different compute unit, this incurs latency due to migrating the working set to a different CU through the caches. When the thread siblings mask mirrors that aspect of the CUs and threads, the scheduler pays attention to it and tries to schedule within one CU first. Which takes care of the latency, of course. Reported-by: Yves Dionne <yves.dionne@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> # 4.9 Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yazen Ghannam <yazen.ghannam@amd.com> Link: http://lkml.kernel.org/r/20170205105022.8705-1-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-15x86/smpboot: Prevent false positive out of bounds cpumask access warningThomas Gleixner
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>
2016-12-13x86/smpboot: Make logical package management more robustThomas Gleixner
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: d49597fd3bc7 ("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>
2016-12-12Merge branch 'x86-idle-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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
2016-12-12Merge branch 'x86-fpu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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
2016-12-12Merge branch 'x86-cpu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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: "
2016-12-12Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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 ...
2016-12-12Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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 ...
2016-12-09x86: Remove empty idle.h headerThomas Gleixner
One include less is always a good thing(tm). Good riddance. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/20161209182912.2726-6-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-09x86/amd: Simplify AMD E400 aware idle routineBorislav Petkov
Reorganize the E400 detection now that we have everything in place: switch the CPUs to broadcast mode after the LAPIC has been initialized and remove the facilities that were used previously on the idle path. Unfortunately static_cpu_has_bug() cannpt be used in the E400 idle routine because alternatives have been applied when the actual detection happens, so the static switching does not take effect and the test will stay false. Use boot_cpu_has_bug() instead which is definitely an improvement over the RDMSR and the cpumask handling. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/20161209182912.2726-5-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-24x86/sched: Add SD_ASYM_PACKING flags to x86 ITMT CPUTim Chen
Some Intel cores in a package can be boosted to a higher turbo frequency with ITMT 3.0 technology. The scheduler can use the asymmetric packing feature to move tasks to the more capable cores. If ITMT is enabled, add SD_ASYM_PACKING flag to the thread and core sched domains to enable asymmetric packing. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/9bbb885bedbef4eb50e197305eb16b160cff0831.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-24x86/topology: Define x86's arch_update_cpu_topologyTim Chen
The scheduler calls arch_update_cpu_topology() to check whether the scheduler domains have to be rebuilt. So far x86 has no requirement for this, but the upcoming ITMT support makes this necessary. Request the rebuild when the x86 internal update flag is set. Suggested-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/bfbf5591276ec60b2af2da798adc1060df1e2a5f.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-01Merge branch 'core/urgent' into x86/fpu, to merge fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-01Merge branch 'linus' into x86/asm, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-26kernel/smp: Make the SMP boot message common on all archesMichael Ellerman
Currently after bringing up secondary CPUs all arches print "Brought up %d CPUs". On x86 they also print the number of nodes that were brought online. It would be nice to also print the number of nodes on other arches. Although we could override smp_announce() on the other ~10 NUMA aware arches, it seems simpler to just always print the number of nodes. On non-NUMA arches there is just always 1 node. Having done that, smp_announce() is no longer weak, and seems small enough to just pull directly into smp_init(). Also update the printing of "%d CPUs" to be smart when an SMP kernel is booted on a single CPU system, or when only one CPU is available, eg: smp: Brought up 2 nodes, 1 CPU Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: akpm@osdl.org Cc: jgross@suse.com Cc: ak@linux.intel.com Cc: tim.c.chen@linux.intel.com Cc: len.brown@intel.com Cc: peterz@infradead.org Cc: richard@nod.at Cc: jolsa@redhat.com Cc: boris.ostrovsky@oracle.com Cc: mgorman@techsingularity.net Link: http://lkml.kernel.org/r/1477460275-8266-2-git-send-email-mpe@ellerman.id.au Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-25x86/cpu: Remove the printk format specifier in "CPU0: "Borislav Petkov
We're using a literal, move it into the string. No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.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/20161024173844.23038-2-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-22x86/boot/smp: Don't try to poke disabled/non-existent APICVille Syrjälä
Apparently trying to poke a disabled or non-existent APIC leads to a box that doesn't even boot. Let's not do that. No real clue if this is the right fix, but at least my P3 machine boots again. Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Cc: dyoung@redhat.com Cc: kexec@lists.infradead.org Cc: stable@vger.kernel.org Fixes: 2a51fe083eba ("arch/x86: Handle non enumerated CPU after physical hotplug") Link: http://lkml.kernel.org/r/1477102684-5092-1-git-send-email-ville.syrjala@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-20x86/boot/smp/32: Fix initial idle stack location on 32-bit kernelsJosh Poimboeuf
On 32-bit kernels, the initial idle stack calculation doesn't take into account the TOP_OF_KERNEL_STACK_PADDING, making the stack end address inconsistent with other tasks on 32-bit. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/6cf569410bfa84cf923902fc4d628444cace94be.1474480779.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-16Merge tag 'v4.9-rc1' into x86/fpu, to resolve conflictIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-16x86/fpu: Remove 'cpu' argument from __cpu_invalidate_fpregs_state()Rik van Riel
The __{fpu,cpu}_invalidate_fpregs_state() functions can only be used to invalidate a resource they control. Document that, and change the API a little bit to reflect that. Go back to open coding the fpu_fpregs_owner_ctx write in the CPU hotplug code, which should be the exception, and move __kernel_fpu_begin() to this API. This patch has no functional changes to the current code. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1476447331-21566-2-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-07arch/x86: Handle non enumerated CPU after physical hotplugPrarit Bhargava
When a CPU is physically added to a system then the MADT table is not updated. If subsequently a kdump kernel is started on that physically added CPU then the ACPI enumeration fails to provide the information for this CPU which is now the boot CPU of the kdump kernel. As a consequence, generic_processor_info() is not invoked for that CPU so the number of enumerated processors is 0 and none of the initializations, including the logical package id management, are performed. We have code which relies on the correctness of the logical package map and other information which is initialized via generic_processor_info(). Executing such code will result in undefined behaviour or kernel crashes. This problem applies only to the kdump kernel because a normal kexec will switch to the original boot CPU, which is enumerated in MADT, before jumping into the kexec kernel. The boot code already has a check for num_processors equal 0 in prefill_possible_map(). We can use that check as an indicator that the enumeration of the boot CPU did not happen and invoke generic_processor_info() for it. That initializes the relevant data for the boot CPU and therefore prevents subsequent failure. [ tglx: Refined the code and rewrote the changelog ] Signed-off-by: Prarit Bhargava <prarit@redhat.com> Fixes: 1f12e32f4cd5 ("x86/topology: Create logical package id") Cc: Peter Zijlstra <peterz@infradead.org> Cc: Len Brown <len.brown@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: dyoung@redhat.com Cc: Eric Biederman <ebiederm@xmission.com> Cc: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/1475514432-27682-1-git-send-email-prarit@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-07x86/fpu: Rename lazy restore functions to "register state valid"Rik van Riel
Name the functions after the state they track, rather than the function they currently enable. This should make it more obvious when we use the fpu_register_state_valid() function for something else in the future. Signed-off-by: Rik van Riel <riel@redhat.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: pbonzini@redhat.com Link: http://lkml.kernel.org/r/1475627678-20788-8-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-03Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull CPU hotplug updates from Thomas Gleixner: "Yet another batch of cpu hotplug core updates and conversions: - Provide core infrastructure for multi instance drivers so the drivers do not have to keep custom lists. - Convert custom lists to the new infrastructure. The block-mq custom list conversion comes through the block tree and makes the diffstat tip over to more lines removed than added. - Handle unbalanced hotplug enable/disable calls more gracefully. - Remove the obsolete CPU_STARTING/DYING notifier support. - Convert another batch of notifier users. The relayfs changes which conflicted with the conversion have been shipped to me by Andrew. The remaining lot is targeted for 4.10 so that we finally can remove the rest of the notifiers" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) cpufreq: Fix up conversion to hotplug state machine blk/mq: Reserve hotplug states for block multiqueue x86/apic/uv: Convert to hotplug state machine s390/mm/pfault: Convert to hotplug state machine mips/loongson/smp: Convert to hotplug state machine mips/octeon/smp: Convert to hotplug state machine fault-injection/cpu: Convert to hotplug state machine padata: Convert to hotplug state machine cpufreq: Convert to hotplug state machine ACPI/processor: Convert to hotplug state machine virtio scsi: Convert to hotplug state machine oprofile/timer: Convert to hotplug state machine block/softirq: Convert to hotplug state machine lib/irq_poll: Convert to hotplug state machine x86/microcode: Convert to hotplug state machine sh/SH-X3 SMP: Convert to hotplug state machine ia64/mca: Convert to hotplug state machine ARM/OMAP/wakeupgen: Convert to hotplug state machine ARM/shmobile: Convert to hotplug state machine arm64/FP/SIMD: Convert to hotplug state machine ...
2016-10-03Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull low-level x86 updates from Ingo Molnar: "In this cycle this topic tree has become one of those 'super topics' that accumulated a lot of changes: - Add CONFIG_VMAP_STACK=y support to the core kernel and enable it on x86 - preceded by an array of changes. v4.8 saw preparatory changes in this area already - this is the rest of the work. Includes the thread stack caching performance optimization. (Andy Lutomirski) - switch_to() cleanups and all around enhancements. (Brian Gerst) - A large number of dumpstack infrastructure enhancements and an unwinder abstraction. The secret long term plan is safe(r) live patching plus maybe another attempt at debuginfo based unwinding - but all these current bits are standalone enhancements in a frame pointer based debug environment as well. (Josh Poimboeuf) - More __ro_after_init and const annotations. (Kees Cook) - Enable KASLR for the vmemmap memory region. (Thomas Garnier)" [ The virtually mapped stack changes are pretty fundamental, and not x86-specific per se, even if they are only used on x86 right now. ] * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) x86/asm: Get rid of __read_cr4_safe() thread_info: Use unsigned long for flags x86/alternatives: Add stack frame dependency to alternative_call_2() x86/dumpstack: Fix show_stack() task pointer regression x86/dumpstack: Remove dump_trace() and related callbacks x86/dumpstack: Convert show_trace_log_lvl() to use the new unwinder oprofile/x86: Convert x86_backtrace() to use the new unwinder x86/stacktrace: Convert save_stack_trace_*() to use the new unwinder perf/x86: Convert perf_callchain_kernel() to use the new unwinder x86/unwind: Add new unwind interface and implementations x86/dumpstack: Remove NULL task pointer convention fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK lib/syscall: Pin the task stack in collect_syscall() x86/process: Pin the target stack in get_wchan() x86/dumpstack: Pin the target stack when dumping it kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function sched/core: Add try_get_task_stack() and put_task_stack() x86/entry/64: Fix a minor comment rebase error iommu/amd: Don't put completion-wait semaphore on stack ...
2016-10-03Merge branch 'x86-apic-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 apic updates from Ingo Molnar: "The main changes are: - Persistent CPU/node numbering across CPU hotplug/unplug events. This is a pretty involved series of changes that first fetches all the information during bootup and then uses it for the various hotplug/unplug methods. (Gu Zheng, Dou Liyang) - IO-APIC hot-add/remove fixes and enhancements. (Rui Wang) - ... various fixes, cleanups and enhancements" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) x86/apic: Fix silent & fatal merge conflict in __generic_processor_info() acpi: Fix broken error check in map_processor() acpi: Validate processor id when mapping the processor acpi: Provide mechanism to validate processors in the ACPI tables x86/acpi: Set persistent cpuid <-> nodeid mapping when booting x86/acpi: Enable MADT APIs to return disabled apicids x86/acpi: Introduce persistent storage for cpuid <-> apicid mapping x86/acpi: Enable acpi to register all possible cpus at boot time x86/numa: Online memory-less nodes at boot time x86/apic: Get rid of apic_version[] array x86/apic: Order irq_enter/exit() calls correctly vs. ack_APIC_irq() x86/ioapic: Ignore root bridges without a companion ACPI device x86/apic: Update comment about disabling processor focus x86/smpboot: Check APIC ID before setting up default routing x86/ioapic: Fix IOAPIC failing to request resource x86/ioapic: Fix lost IOAPIC resource after hot-removal and hotadd x86/ioapic: Fix setup_res() failing to get resource x86/ioapic: Support hot-removal of IOAPICs present during boot x86/ioapic: Change prototype of acpi_ioapic_add() x86/apic, ACPI: Fix incorrect assignment when handling apic/x2apic entries ...
2016-09-30sched/core, x86/topology: Fix NUMA in package topology bugTim Chen
Current code can call set_cpu_sibling_map() and invoke sched_set_topology() more than once (e.g. on CPU hot plug). When this happens after sched_init_smp() has been called, we lose the NUMA topology extension to sched_domain_topology in sched_init_numa(). This results in incorrect topology when the sched domain is rebuilt. This patch fixes the bug and issues warning if we call sched_set_topology() after sched_init_smp(). Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/1474485552-141429-2-git-send-email-srinivas.pandruvada@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-26Merge branch 'x86/urgent' into x86/apicThomas Gleixner
Bring in the upstream modifications so we can fixup the silent merge conflict which is introduced by this merge. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-20x86/apic: Get rid of apic_version[] arrayDenys Vlasenko
The array has a size of MAX_LOCAL_APIC, which can be as large as 32k, so it can consume up to 128k. The array has been there forever and was never used for anything useful other than a version mismatch check which was introduced in 2009. There is no reason to store the version in an array. The kernel is not prepared to handle different APIC versions anyway, so the real important part is to detect a version mismatch and warn about it, which can be done with a single variable as well. [ tglx: Massaged changelog ] Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> CC: Andy Lutomirski <luto@amacapital.net> CC: Borislav Petkov <bp@alien8.de> CC: Brian Gerst <brgerst@gmail.com> CC: Mike Travis <travis@sgi.com> Link: http://lkml.kernel.org/r/20160913181232.30815-1-dvlasenk@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-01Merge branch 'linus' into smp/hotplugThomas Gleixner
Apply upstream changes to avoid conflicts with pending patches.
2016-08-24sched/x86: Rewrite the switch_to() codeBrian Gerst
Move the low-level context switch code to an out-of-line asm stub instead of using complex inline asm. This allows constructing a new stack frame for the child process to make it seamlessly flow to ret_from_fork without an extra test and branch in __switch_to(). It also improves code generation for __schedule() by using the C calling convention instead of clobbering all registers. Signed-off-by: Brian Gerst <brgerst@gmail.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.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/1471106302-10159-5-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-24x86/smpboot: Check APIC ID before setting up default routingWei Jiangang
This is not a bugfix, but code optimization. If the BSP's APIC ID in local APIC is unexpected, a kernel panic will occur and the system will halt. That means no need to enable APIC mode, and no reason to set up the default routing for APIC. The combination of default_setup_apic_routing() and apic_bsp_setup() are used to enable APIC mode. They two should be kept together, rather than being separated by the codes of checking APIC ID. Just like their usage in APIC_init_uniprocessor(). Signed-off-by: Wei Jiangang <weijg.fnst@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Link: http://lkml.kernel.org/r/1471576957-12961-1-git-send-email-weijg.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-18x86/asm/head: Rename 'stack_start' -> 'initial_stack'Josh Poimboeuf
The 'stack_start' variable is similar in usage to 'initial_code' and 'initial_gs': they're all stored in head_64.S and they're all updated by SMP and ACPI suspend before starting a CPU. Rename it to 'initial_stack' to be consistent with the others. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/87063d773a3212051b77e17b0ee427f6582a5050.1471535549.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-18x86/smp: Fix __max_logical_packages value setupJiri Olsa
Frank reported kernel panic when he disabled several cores in BIOS via following option: Core Disable Bitmap(Hex) [0] with number 0xFFE, which leaves 16 CPUs in system (out of 48). The kernel panic below goes along with following messages: smpboot: Max logical packages: 2^M smpboot: APIC(0) Converting physical 0 to logical package 0^M smpboot: APIC(20) Converting physical 1 to logical package 1^M smpboot: APIC(40) Package 2 exceeds logical package map^M smpboot: CPU 8 APICId 40 disabled^M smpboot: APIC(60) Package 3 exceeds logical package map^M smpboot: CPU 12 APICId 60 disabled^M ... general protection fault: 0000 [#1] SMP^M Modules linked in:^M CPU: 15 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc5+ #1^M Hardware name: SGI UV300/UV300, BIOS SGI UV 300 series BIOS 05/25/2016^M task: ffff8801673e0000 ti: ffff8801673ac000 task.ti: ffff8801673ac000^M RIP: 0010:[<ffffffff81014d54>] [<ffffffff81014d54>] uncore_change_context+0xd4/0x180^M ... [<ffffffff810158ac>] uncore_event_init_cpu+0x6c/0x70^M [<ffffffff81d8c91c>] intel_uncore_init+0x1c2/0x2dd^M [<ffffffff81d8c75a>] ? uncore_cpu_setup+0x17/0x17^M [<ffffffff81002190>] do_one_initcall+0x50/0x190^M [<ffffffff810ab193>] ? parse_args+0x293/0x480^M [<ffffffff81d87365>] kernel_init_freeable+0x1a5/0x249^M [<ffffffff81d86a35>] ? set_debug_rodata+0x12/0x12^M [<ffffffff816dc19e>] kernel_init+0xe/0x110^M [<ffffffff816e93bf>] ret_from_fork+0x1f/0x40^M [<ffffffff816dc190>] ? rest_init+0x80/0x80^M The reason for the panic is wrong value of __max_logical_packages, which lets logical_package_map uninitialized and the uncore code relying on this map being properly initialized (maybe we should add some safety checks there as well). The __max_logical_packages is computed as: DIV_ROUND_UP(total_cpus, ncpus); - ncpus being number of cores With above BIOS setup we get total_cpus == 16 which set __max_logical_packages to 2 (ncpus is 12). Once topology_update_package_map processes CPU with logical pkg over 2 we display above messages and fail to initialize the physical_to_logical_pkg map, which makes the uncore code crash. The fix is to remove logical_package_map bitmap completely and keep and update the logical_packages number instead. After we enumerate all the present CPUs, we check if the enumerated logical packages count is within its computed maximum from BIOS data. If it's not the case, we set this maximum to the new enumerated value and freeze any new addition of logical packages. The freeze is because lot of init code like uncore/rapl/cqm depends on having maximum logical package value set to allocate their data, so we can't change it later on. Prarit Bhargava tested the patch and confirms that it solves the problem: From dmidecode: Core Count: 24 Core Enabled: 24 Thread Count: 48 Orig kernel boot log: [ 0.464981] smpboot: Max logical packages: 19 [ 0.469861] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.477261] smpboot: APIC(40) Converting physical 1 to logical package 1 [ 0.484760] smpboot: APIC(80) Converting physical 2 to logical package 2 [ 0.492258] smpboot: APIC(c0) Converting physical 3 to logical package 3 1. nr_cpus=8, should stop enumerating in package 0: [ 0.533664] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.539596] smpboot: Max logical packages: 19 2. max_cpus=8, should still enumerate all packages: [ 0.526494] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.532428] smpboot: APIC(40) Converting physical 1 to logical package 1 [ 0.538456] smpboot: APIC(80) Converting physical 2 to logical package 2 [ 0.544486] smpboot: APIC(c0) Converting physical 3 to logical package 3 [ 0.550524] smpboot: Max logical packages: 19 3. nr_cpus=49 ( 2 socket + 1 core on 3rd socket), should stop enumerating in package 2: [ 0.521378] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.527314] smpboot: APIC(40) Converting physical 1 to logical package 1 [ 0.533345] smpboot: APIC(80) Converting physical 2 to logical package 2 [ 0.539368] smpboot: Max logical packages: 19 4. maxcpus=49, should still enumerate all packages: [ 0.525591] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.531525] smpboot: APIC(40) Converting physical 1 to logical package 1 [ 0.537547] smpboot: APIC(80) Converting physical 2 to logical package 2 [ 0.543579] smpboot: APIC(c0) Converting physical 3 to logical package 3 [ 0.549624] smpboot: Max logical packages: 19 5. kdump (nr_cpus=1) works as well. Reported-by: Frank Ramsay <framsay@redhat.com> Tested-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Reviewed-by: Prarit Bhargava <prarit@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160815101700.GA30090@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10cpu/hotplug: Prevent alloc/free of irq descriptors during CPU up/down (again)Boris Ostrovsky
Now that Xen no longer allocates irqs in _cpu_up() we can restore commit: a89941816726 ("hotplug: Prevent alloc/free of irq descriptors during cpu up/down") Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: david.vrabel@citrix.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1470244948-17674-3-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-01Merge branch 'x86-headers-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 header cleanups from Ingo Molnar: "This tree is a cleanup of the x86 tree reducing spurious uses of module.h - which should improve build performance a bit" * 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, crypto: Restore MODULE_LICENSE() to glue_helper.c so it loads x86/apic: Remove duplicated include from probe_64.c x86/ce4100: Remove duplicated include from ce4100.c x86/headers: Include spinlock_types.h in x8664_ksyms_64.c for missing spinlock_t x86/platform: Delete extraneous MODULE_* tags fromm ts5500 x86: Audit and remove any remaining unnecessary uses of module.h x86/kvm: Audit and remove any unnecessary uses of module.h x86/xen: Audit and remove any unnecessary uses of module.h x86/platform: Audit and remove any unnecessary uses of module.h x86/lib: Audit and remove any unnecessary uses of module.h x86/kernel: Audit and remove any unnecessary uses of module.h x86/mm: Audit and remove any unnecessary uses of module.h x86: Don't use module.h just for AUTHOR / LICENSE tags
2016-07-26Merge tag 'pm-4.8-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "Again, the majority of changes go into the cpufreq subsystem, but there are no big features this time. The cpufreq changes that stand out somewhat are the governor interface rework and improvements related to the handling of frequency tables. Apart from those, there are fixes and new device/CPU IDs in drivers, cleanups and an improvement of the new schedutil governor. Next, there are some changes in the hibernation core, including a fix for a nasty problem related to the MONITOR/MWAIT usage by CPU offline during resume from hibernation, a few core improvements related to memory management during resume, a couple of additional debug features and cleanups. Finally, we have some fixes and cleanups in the devfreq subsystem, generic power domains framework improvements related to system suspend/resume, support for some new chips in intel_idle and in the power capping RAPL driver, a new version of the AnalyzeSuspend utility and some assorted fixes and cleanups. Specifics: - Rework the cpufreq governor interface to make it more straightforward and modify the conservative governor to avoid using transition notifications (Rafael Wysocki). - Rework the handling of frequency tables by the cpufreq core to make it more efficient (Viresh Kumar). - Modify the schedutil governor to reduce the number of wakeups it causes to occur in cases when the CPU frequency doesn't need to be changed (Steve Muckle, Viresh Kumar). - Fix some minor issues and clean up code in the cpufreq core and governors (Rafael Wysocki, Viresh Kumar). - Add Intel Broxton support to the intel_pstate driver (Srinivas Pandruvada). - Fix problems related to the config TDP feature and to the validity of the MSR_HWP_INTERRUPT register in intel_pstate (Jan Kiszka, Srinivas Pandruvada). - Make intel_pstate update the cpu_frequency tracepoint even if the frequency doesn't change to avoid confusing powertop (Rafael Wysocki). - Clean up the usage of __init/__initdata in intel_pstate, mark some of its internal variables as __read_mostly and drop an unused structure element from it (Jisheng Zhang, Carsten Emde). - Clean up the usage of some duplicate MSR symbols in intel_pstate and turbostat (Srinivas Pandruvada). - Update/fix the powernv, s3c24xx and mvebu cpufreq drivers (Akshay Adiga, Viresh Kumar, Ben Dooks). - Fix a regression (introduced during the 4.5 cycle) in the pcc-cpufreq driver by reverting the problematic commit (Andreas Herrmann). - Add support for Intel Denverton to intel_idle, clean up Broxton support in it and make it explicitly non-modular (Jacob Pan, Jan Beulich, Paul Gortmaker). - Add support for Denverton and Ivy Bridge server to the Intel RAPL power capping driver and make it more careful about the handing of MSRs that may not be present (Jacob Pan, Xiaolong Wang). - Fix resume from hibernation on x86-64 by making the CPU offline during resume avoid using MONITOR/MWAIT in the "play dead" loop which may lead to an inadvertent "revival" of a "dead" CPU and a page fault leading to a kernel crash from it (Rafael Wysocki). - Make memory management during resume from hibernation more straightforward (Rafael Wysocki). - Add debug features that should help to detect problems related to hibernation and resume from it (Rafael Wysocki, Chen Yu). - Clean up hibernation core somewhat (Rafael Wysocki). - Prevent KASAN from instrumenting the hibernation core which leads to large numbers of false-positives from it (James Morse). - Prevent PM (hibernate and suspend) notifiers from being called during the cleanup phase if they have not been called during the corresponding preparation phase which is possible if one of the other notifiers returns an error at that time (Lianwei Wang). - Improve suspend-related debug printout in the tasks freezer and clean up suspend-related console handling (Roger Lu, Borislav Petkov). - Update the AnalyzeSuspend script in the kernel sources to version 4.2 (Todd Brandt). - Modify the generic power domains framework to make it handle system suspend/resume better (Ulf Hansson). - Make the runtime PM framework avoid resuming devices synchronously when user space changes the runtime PM settings for them and improve its error reporting (Rafael Wysocki, Linus Walleij). - Fix error paths in devfreq drivers (exynos, exynos-ppmu, exynos-bus) and in the core, make some devfreq code explicitly non-modular and change some of it into tristate (Bartlomiej Zolnierkiewicz, Peter Chen, Paul Gortmaker). - Add DT support to the generic PM clocks management code and make it export some more symbols (Jon Hunter, Paul Gortmaker). - Make the PCI PM core code slightly more robust against possible driver errors (Andy Shevchenko). - Make it possible to change DESTDIR and PREFIX in turbostat (Andy Shevchenko)" * tag 'pm-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (89 commits) Revert "cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency" PM / hibernate: Introduce test_resume mode for hibernation cpufreq: export cpufreq_driver_resolve_freq() cpufreq: Disallow ->resolve_freq() for drivers providing ->target_index() PCI / PM: check all fields in pci_set_platform_pm() cpufreq: acpi-cpufreq: use cached frequency mapping when possible cpufreq: schedutil: map raw required frequency to driver frequency cpufreq: add cpufreq_driver_resolve_freq() cpufreq: intel_pstate: Check cpuid for MSR_HWP_INTERRUPT intel_pstate: Update cpu_frequency tracepoint every time cpufreq: intel_pstate: clean remnant struct element PM / tools: scripts: AnalyzeSuspend v4.2 x86 / hibernate: Use hlt_play_dead() when resuming from hibernation cpufreq: powernv: Replacing pstate_id with frequency table index intel_pstate: Fix MSR_CONFIG_TDP_x addressing in core_get_max_pstate() PM / hibernate: Image data protection during restoration PM / hibernate: Add missing braces in __register_nosave_region() PM / hibernate: Clean up comments in snapshot.c PM / hibernate: Clean up function headers in snapshot.c PM / hibernate: Add missing braces in hibernate_setup() ...
2016-07-25Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "Various x86 low level modifications: - preparatory work to support virtually mapped kernel stacks (Andy Lutomirski) - support for 64-bit __get_user() on 32-bit kernels (Benjamin LaHaise) - (involved) workaround for Knights Landing CPU erratum (Dave Hansen) - MPX enhancements (Dave Hansen) - mremap() extension to allow remapping of the special VDSO vma, for purposes of user level context save/restore (Dmitry Safonov) - hweight and entry code cleanups (Borislav Petkov) - bitops code generation optimizations and cleanups with modern GCC (H. Peter Anvin) - syscall entry code optimizations (Paolo Bonzini)" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits) x86/mm/cpa: Add missing comment in populate_pdg() x86/mm/cpa: Fix populate_pgd(): Stop trying to deallocate failed PUDs x86/syscalls: Add compat_sys_preadv64v2/compat_sys_pwritev64v2 x86/smp: Remove unnecessary initialization of thread_info::cpu x86/smp: Remove stack_smp_processor_id() x86/uaccess: Move thread_info::addr_limit to thread_struct x86/dumpstack: Rename thread_struct::sig_on_uaccess_error to sig_on_uaccess_err x86/uaccess: Move thread_info::uaccess_err and thread_info::sig_on_uaccess_err to thread_struct x86/dumpstack: When OOPSing, rewind the stack before do_exit() x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm x86/dumpstack/64: Handle faults when printing the "Stack: " part of an OOPS x86/dumpstack: Try harder to get a call trace on stack overflow x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables() x86/mm/cpa: In populate_pgd(), don't set the PGD entry until it's populated x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() x86/mm: Use pte_none() to test for empty PTE x86/mm: Disallow running with 32-bit PTEs to work around erratum x86/mm: Ignore A/D bits in pte/pmd/pud_none() x86/mm: Move swap offset/type up in PTE to work around erratum x86/entry: Inline enter_from_user_mode() ...
2016-07-15x86 / hibernate: Use hlt_play_dead() when resuming from hibernationRafael J. Wysocki
On Intel hardware, native_play_dead() uses mwait_play_dead() by default and only falls back to the other methods if that fails. That also happens during resume from hibernation, when the restore (boot) kernel runs disable_nonboot_cpus() to take all of the CPUs except for the boot one offline. However, that is problematic, because the address passed to __monitor() in mwait_play_dead() is likely to be written to in the last phase of hibernate image restoration and that causes the "dead" CPU to start executing instructions again. Unfortunately, the page containing the address in that CPU's instruction pointer may not be valid any more at that point. First, that page may have been overwritten with image kernel memory contents already, so the instructions the CPU attempts to execute may simply be invalid. Second, the page tables previously used by that CPU may have been overwritten by image kernel memory contents, so the address in its instruction pointer is impossible to resolve then. A report from Varun Koyyalagunta and investigation carried out by Chen Yu show that the latter sometimes happens in practice. To prevent it from happening, temporarily change the smp_ops.play_dead pointer during resume from hibernation so that it points to a special "play dead" routine which uses hlt_play_dead() and avoids the inadvertent "revivals" of "dead" CPUs this way. A slightly unpleasant consequence of this change is that if the system is hibernated with one or more CPUs offline, it will generally draw more power after resume than it did before hibernation, because the physical state entered by CPUs via hlt_play_dead() is higher-power than the mwait_play_dead() one in the majority of cases. It is possible to work around this, but it is unclear how much of a problem that's going to be in practice, so the workaround will be implemented later if it turns out to be necessary. Link: https://bugzilla.kernel.org/show_bug.cgi?id=106371 Reported-by: Varun Koyyalagunta <cpudebug@centtech.com> Original-by: Chen Yu <yu.c.chen@intel.com> Tested-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ingo Molnar <mingo@kernel.org>
2016-07-15x86/smp: Remove unnecessary initialization of thread_info::cpuAndy Lutomirski
It's statically initialized to zero -- no need to dynamically initialize it to zero as well. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.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/6cf6314dce3051371a913ee19d1b88e29c68c560.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-14x86/kernel: Audit and remove any unnecessary uses of module.hPaul Gortmaker
Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace as needed. Build testing revealed some implicit header usage that was fixed up accordingly. Note that some bool/obj-y instances remain since module.h is the header for some exception table entry stuff, and for things like __init_or_module (code that is tossed when MODULES=n). Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.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/20160714001901.31603-4-paul.gortmaker@windriver.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-03x86/topology: Add topology_max_smt_threads()Andi Kleen
For SMT specific workarounds it is useful to know if SMT is active on any online CPU in the system. This currently requires a loop over all online CPUs. Add a global variable that is updated with the maximum number of smt threads on any CPU on online/offline, and use it for topology_max_smt_threads() The single call is easier to use than a loop. Not exported to user space because user space already can use the existing sibling interfaces to find this out. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1463703002-19686-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-16Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this cycle were: - MSR access API fixes and enhancements (Andy Lutomirski) - early exception handling improvements (Andy Lutomirski) - user-space FS/GS prctl usage fixes and improvements (Andy Lutomirski) - Remove the cpu_has_*() APIs and replace them with equivalents (Borislav Petkov) - task switch micro-optimization (Brian Gerst) - 32-bit entry code simplification (Denys Vlasenko) - enhance PAT handling in enumated CPUs (Toshi Kani) ... and lots of other cleanups/fixlets" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) x86/arch_prctl/64: Restore accidentally removed put_cpu() in ARCH_SET_GS x86/entry/32: Remove asmlinkage_protect() x86/entry/32: Remove GET_THREAD_INFO() from entry code x86/entry, sched/x86: Don't save/restore EFLAGS on task switch x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs selftests/x86/ldt_gdt: Test set_thread_area() deletion of an active segment x86/tls: Synchronize segment registers in set_thread_area() x86/asm/64: Rename thread_struct's fs and gs to fsbase and gsbase x86/arch_prctl/64: Remove FSBASE/GSBASE < 4G optimization x86/segments/64: When load_gs_index fails, clear the base x86/segments/64: When loadsegment(fs, ...) fails, clear the base x86/asm: Make asm/alternative.h safe from assembly x86/asm: Stop depending on ptrace.h in alternative.h x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall() x86/asm: Make sure verify_cpu() has a good stack x86/extable: Add a comment about early exception handlers x86/msr: Set the return value to zero when native_rdmsr_safe() fails x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y x86/paravirt: Add paravirt_{read,write}_msr() x86/msr: Carry on after a non-"safe" MSR access fails ...
2016-05-07x86/topology: Handle CPUID bogosity gracefullyThomas Gleixner
Joseph reported that a XEN guest dies with a division by 0 in the package topology setup code. This happens if cpu_info.x86_max_cores is zero. Handle that case and emit a warning. This does not fix the underlying XEN bug, but makes the code more robust. Reported-and-tested-by: Joseph Salisbury <joseph.salisbury@canonical.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1605062046270.3540@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-04-13x86/cpufeature: Replace cpu_has_apic with boot_cpu_has() usageBorislav Petkov
Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: iommu@lists.linux-foundation.org Cc: linux-pm@vger.kernel.org Cc: oprofile-list@lists.sf.net Link: http://lkml.kernel.org/r/1459801503-15600-8-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-29x86/cpu: Get rid of compute_unit_idBorislav Petkov
It is cpu_core_id anyway. Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1458917557-8757-3-git-send-email-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-03-19x86/topology: Use total_cpus not nr_cpu_ids for logical packagesThomas Gleixner
nr_cpu_ids can be limited on the command line via nr_cpus=. That can break the logical package management because it results in a smaller number of packages, but the cpus to online are occupying the full package space as the hyper threads are enumerated after the physical cores typically. total_cpus is the real possible cpu space not limited by nr_cpus command line and gives us the proper number of packages. Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Fixes: 1f12e32f4cd5 ("x86/topology: Create logical package id") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Xiong Zhou <jencce.kernel@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Andreas Herrmann <aherrmann@suse.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1603181254330.3978@nanos
2016-03-19x86/topology: Fix Intel HT disablePeter Zijlstra
As per the comment in the code; due to BIOS it is sometimes impossible to know if there actually are smp siblings until the machine is fully enumerated. So we rather overestimate the number of possible packages. Fixes: 1f12e32f4cd5 ("x86/topology: Create logical package id") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: aherrmann@suse.com Cc: jencce.kernel@gmail.com Cc: bp@alien8.de Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Link: http://lkml.kernel.org/r/20160318150538.611014173@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-03-19x86/topology: Fix logical package mappingPeter Zijlstra
That first branch testing pkg against __max_logical_packages is wrong, because if the first pkg id is larger, then the find_first_zero will find us logical package id 0. However, if the second pkg id is indeed 0, we'll again claim it without testing if it was already taken. Also, it fails to print the mapping. Fixes: 1f12e32f4cd5 ("x86/topology: Create logical package id") Reported-by: Xiong Zhou <jencce.kernel@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: aherrmann@suse.com Cc: bp@alien8.de Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Link: http://lkml.kernel.org/r/20160317095220.GO6344@twins.programming.kicks-ass.net Link: http://lkml.kernel.org/r/20160318150538.482393396@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-03-15Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull cpu hotplug updates from Thomas Gleixner: "This is the first part of the ongoing cpu hotplug rework: - Initial implementation of the state machine - Runs all online and prepare down callbacks on the plugged cpu and not on some random processor - Replaces busy loop waiting with completions - Adds tracepoints so the states can be followed" More detailed commentary on this work from an earlier email: "What's wrong with the current cpu hotplug infrastructure? - Asymmetry The hotplug notifier mechanism is asymmetric versus the bringup and teardown. This is mostly caused by the notifier mechanism. - Largely undocumented dependencies While some notifiers use explicitely defined notifier priorities, we have quite some notifiers which use numerical priorities to express dependencies without any documentation why. - Control processor driven Most of the bringup/teardown of a cpu is driven by a control processor. While it is understandable, that preperatory steps, like idle thread creation, memory allocation for and initialization of essential facilities needs to be done before a cpu can boot, there is no reason why everything else must run on a control processor. Before this patch series, bringup looks like this: Control CPU Booting CPU do preparatory steps kick cpu into life do low level init sync with booting cpu sync with control cpu bring the rest up - All or nothing approach There is no way to do partial bringups. That's something which is really desired because we waste e.g. at boot substantial amount of time just busy waiting that the cpu comes to life. That's stupid as we could very well do preparatory steps and the initial IPI for other cpus and then go back and do the necessary low level synchronization with the freshly booted cpu. - Minimal debuggability Due to the notifier based design, it's impossible to switch between two stages of the bringup/teardown back and forth in order to test the correctness. So in many hotplug notifiers the cancel mechanisms are either not existant or completely untested. - Notifier [un]registering is tedious To [un]register notifiers we need to protect against hotplug at every callsite. There is no mechanism that bringup/teardown callbacks are issued on the online cpus, so every caller needs to do it itself. That also includes error rollback. What's the new design? The base of the new design is a symmetric state machine, where both the control processor and the booting/dying cpu execute a well defined set of states. Each state is symmetric in the end, except for some well defined exceptions, and the bringup/teardown can be stopped and reversed at almost all states. So the bringup of a cpu will look like this in the future: Control CPU Booting CPU do preparatory steps kick cpu into life do low level init sync with booting cpu sync with control cpu bring itself up The synchronization step does not require the control cpu to wait. That mechanism can be done asynchronously via a worker or some other mechanism. The teardown can be made very similar, so that the dying cpu cleans up and brings itself down. Cleanups which need to be done after the cpu is gone, can be scheduled asynchronously as well. There is a long way to this, as we need to refactor the notion when a cpu is available. Today we set the cpu online right after it comes out of the low level bringup, which is not really correct. The proper mechanism is to set it to available, i.e. cpu local threads, like softirqd, hotplug thread etc. can be scheduled on that cpu, and once it finished all booting steps, it's set to online, so general workloads can be scheduled on it. The reverse happens on teardown. First thing to do is to forbid scheduling of general workloads, then teardown all the per cpu resources and finally shut it off completely. This patch series implements the basic infrastructure for this at the core level. This includes the following: - Basic state machine implementation with well defined states, so ordering and prioritization can be expressed. - Interfaces to [un]register state callbacks This invokes the bringup/teardown callback on all online cpus with the proper protection in place and [un]installs the callbacks in the state machine array. For callbacks which have no particular ordering requirement we have a dynamic state space, so that drivers don't have to register an explicit hotplug state. If a callback fails, the code automatically does a rollback to the previous state. - Sysfs interface to drive the state machine to a particular step. This is only partially functional today. Full functionality and therefor testability will be achieved once we converted all existing hotplug notifiers over to the new scheme. - Run all CPU_ONLINE/DOWN_PREPARE notifiers on the booting/dying processor: Control CPU Booting CPU do preparatory steps kick cpu into life do low level init sync with booting cpu sync with control cpu wait for boot bring itself up Signal completion to control cpu In a previous step of this work we've done a full tree mechanical conversion of all hotplug notifiers to the new scheme. The balance is a net removal of about 4000 lines of code. This is not included in this series, as we decided to take a different approach. Instead of mechanically converting everything over, we will do a proper overhaul of the usage sites one by one so they nicely fit into the symmetric callback scheme. I decided to do that after I looked at the ugliness of some of the converted sites and figured out that their hotplug mechanism is completely buggered anyway. So there is no point to do a mechanical conversion first as we need to go through the usage sites one by one again in order to achieve a full symmetric and testable behaviour" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) cpu/hotplug: Document states better cpu/hotplug: Fix smpboot thread ordering cpu/hotplug: Remove redundant state check cpu/hotplug: Plug death reporting race rcu: Make CPU_DYING_IDLE an explicit call cpu/hotplug: Make wait for dead cpu completion based cpu/hotplug: Let upcoming cpu bring itself fully up arch/hotplug: Call into idle with a proper state cpu/hotplug: Move online calls to hotplugged cpu cpu/hotplug: Create hotplug threads cpu/hotplug: Split out the state walk into functions cpu/hotplug: Unpark smpboot threads from the state machine cpu/hotplug: Move scheduler cpu_online notifier to hotplug core cpu/hotplug: Implement setup/removal interface cpu/hotplug: Make target state writeable cpu/hotplug: Add sysfs state interface cpu/hotplug: Hand in target state to _cpu_up/down cpu/hotplug: Convert the hotplugged cpu work to a state machine cpu/hotplug: Convert to a state machine for the control processor cpu/hotplug: Add tracepoints ...
2016-03-01arch/hotplug: Call into idle with a proper stateThomas Gleixner
Let the non boot cpus call into idle with the corresponding hotplug state, so the hotplug core can handle the further bringup. That's a first step to convert the boot side of the hotplugged cpus to do all the synchronization with the other side through the state machine. For now it'll only start the hotplug thread and kick the full bringup of the cpu. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Rik van Riel <riel@redhat.com> Cc: Rafael Wysocki <rafael.j.wysocki@intel.com> Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>