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
...
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>
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: 2a51fe083e ("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>
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: 1f12e32f4c ("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>
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
...
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
...
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
...
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>
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>
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>
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>
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>
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>
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>
Now that Xen no longer allocates irqs in _cpu_up() we can restore
commit:
a899418167 ("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>
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
- 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).
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Merge tag 'pm-4.8-rc1' of 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()
...
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()
...
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>
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>
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>
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>
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
...
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>
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: 1f12e32f4c ("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
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: 1f12e32f4c ("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>
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: 1f12e32f4c ("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>
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
...
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>
For per package oriented services we must be able to rely on the number of CPU
packages to be within bounds. Create a tracking facility, which
- calculates the number of possible packages depending on nr_cpu_ids after boot
- makes sure that the package id is within the number of possible packages. If
the apic id is outside we map it to a logical package id if there is enough
space available.
Provide interfaces for drivers to query the mapping and do translations from
physcial to logical ids.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
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: Harish Chegondi <harish.chegondi@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20160222221011.541071755@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Those are stupid and code should use static_cpu_has_safe() or
boot_cpu_has() instead. Kill the least used and unused ones.
The remaining ones need more careful inspection before a conversion can
happen. On the TODO.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1449481182-27541-4-git-send-email-bp@alien8.de
Cc: David Sterba <dsterba@suse.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
commit f1ccd24931 allowed the cmdline "cpu_init_udelay=" to work
with all values, including the default of 10000.
But in setting the default of 10000, it over-rode the code that sets
the delay 0 on modern processors.
Also, tidy up use of INT/UINT.
Fixes: f1ccd24931 "x86/smpboot: Fix cpu_init_udelay=10000 corner case boot parameter misbehavior"
Reported-by: Shane <shrybman@teksavvy.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: dparsons@brightdsl.net
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/9082eb809ef40dad02db714759c7aaf618c518d4.1448232494.git.len.brown@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The following commit:
a9bcaa02a5 ("x86/smpboot: Remove SIPI delays from cpu_up()")
Caused some Intel Core2 processors to time-out when bringing up CPU #1,
resulting in the missing of that CPU after bootup.
That patch reduced the SIPI delays from udelay() 300, 200 to udelay() 0,
0 on modern processors.
Several Intel(R) Core(TM)2 systems failed to bring up CPU #1 10/10 times
after that change.
Increasing either of the SIPI delays to udelay(1) results in
success. So here we increase both to udelay(10). While this may
be 20x slower than the absolute minimum, it is still 20x to 30x
faster than the original code.
Tested-by: Donald Parsons <dparsons@brightdsl.net>
Tested-by: Shane <shrybman@teksavvy.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dparsons@brightdsl.net
Cc: shrybman@teksavvy.com
Link: http://lkml.kernel.org/r/6dd554ee8945984d85aafb2ad35793174d068af0.1444968087.git.len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For legacy machines cpu_init_udelay defaults to 10,000.
For modern machines it is set to 0.
The user should be able to set cpu_init_udelay to
any value on the cmdline, including 10,000.
Before this patch, that was seen as "unchanged from default"
and thus on a modern machine, the user request was ignored
and the delay was set to 0.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dparsons@brightdsl.net
Cc: shrybman@teksavvy.com
Link: http://lkml.kernel.org/r/de363cdbbcfcca1d22569683f7eb9873e0177251.1444968087.git.len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 init code fixlet from Ingo Molnar:
"A single change: fix obsolete init code annotations"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Drop bogus __ref / __refdata annotations
Both the per-APIC flag ".wait_for_init_deassert",
and the global atomic_t "init_deasserted"
are dead code -- remove them.
For all APIC types, "wait_for_master()"
prevents an AP from proceeding until the BSP has set
cpu_callout_mask, making "init_deasserted" {unnecessary}:
BSP: <de-assert INIT>
...
BSP: {set init_deasserted}
AP: wait_for_master()
set cpu_initialized_mask
wait for cpu_callout_mask
BSP: test cpu_initialized_mask
BSP: set cpu_callout_mask
AP: test cpu_callout_mask
AP: {wait for init_deasserted}
...
AP: <touch APIC>
Deleting the {dead code} above is necessary to enable
some parallelism in a future patch.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/de4b3a9bab894735e285870b5296da25ee6a8a5a.1439739165.git.len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
MPS 1.4 example code shows the following required delays during processor
on-lining:
INIT
udelay(10,000)
SIPI
udelay(200)
SIPI
udelay(200) /* Linux actually implements this as udelay(300) */
Linux skips the udelay(10,000) on modern processors.
This patch removes the udelay(200) after each SIPI
on those same processors.
All three legacy delays can be restored by the cmdline
"cpu_init_udelay=10000".
As measured by analyze_suspend.py, this patch speeds
processor resume time on my desktop from 2.4ms to 1.8ms, per AP.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/a5dfdbc8fbfdd813784da204aad5677fe459ac37.1439739165.git.len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
After the BSP sends INIT/SIPI/SIP to the AP and sees the AP
in the cpu_initialized_map, it sets the AP loose via the
cpu_callout_map, and waits for it via the cpu_callin_map.
The BSP polls the cpu_callin_map with a udelay(100)
and a schedule() in each iteration.
The udelay(100) adds no value.
For example, on my 4-CPU dekstop, the AP finishes
cpu_callin() in under 70 usec and sets the cpu_callin_mask.
The BSP, however, doesn't see that setting until over 30 usec
later, because it was still running its udelay(100)
when the AP finished.
Deleting the udelay(100) in the cpu_callin_mask polling loop,
saves from 0 to 100 usec per Application Processor.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/0aade12eabeb89a688c929fe80856eaea0544bb7.1439739165.git.len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
After the BSP sends the APIC INIT/SIPI/SIPI to the AP,
it waits for the AP to come up and indicate that it is alive
by setting its own bit in the cpu_initialized_mask.
Linux polls for up to 10 seconds for this to happen.
Each polling loop has a udelay(100) and a call to schedule().
The udelay(100) adds no value.
For example, on my desktop, the BSP waits for the
other 3 CPUs to come on line at boot for 305, 404, 405 usec.
For resume from S3, it waits 317, 404, 405 usec.
But when the udelay(100) is removed, the BSP waits
305, 310, 306 for boot, and 305, 307, 306 for resume.
So for both boot and resume, removing the udelay(100)
speeds online by about 100us in 2 of 3 cases.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/33ef746c67d2489cad0a9b1958cf71167232ff2b.1439739165.git.len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The __ref / __refdata annotations used to be needed because of
referencing functions / variables annotated __cpuinit /
__cpuinitdata.
But those annotations vanished during the development of v3.11.
Therefore most of the __ref / __refdata annotations are not needed
anymore. As they may hide legitimate sections mismatches, we
better get rid of them.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1437409973-8927-1-git-send-email-minipli@googlemail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Boris reported that the sparse_irq protection around __cpu_up() in the
generic code causes a regression on Xen. Xen allocates interrupts and
some more in the xen_cpu_up() function, so it deadlocks on the
sparse_irq_lock.
There is no simple fix for this and we really should have the
protection for all architectures, but for now the only solution is to
move it to x86 where actual wreckage due to the lack of protection has
been observed.
Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Fixes: a899418167 'hotplug: Prevent alloc/free of irq descriptors during cpu up/down'
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: xiao jin <jin.xiao@intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>
Jin debugged a nasty cpu hotplug race which results in leaking a irq
vector on the newly hotplugged cpu.
cpu N cpu M
native_cpu_up device_shutdown
do_boot_cpu free_msi_irqs
start_secondary arch_teardown_msi_irqs
smp_callin default_teardown_msi_irqs
setup_vector_irq arch_teardown_msi_irq
__setup_vector_irq native_teardown_msi_irq
lock(vector_lock) destroy_irq
install vectors
unlock(vector_lock)
lock(vector_lock)
---> __clear_irq_vector
unlock(vector_lock)
lock(vector_lock)
set_cpu_online
unlock(vector_lock)
This leaves the irq vector(s) which are torn down on CPU M stale in
the vector array of CPU N, because CPU M does not see CPU N online
yet. There is a similar issue with concurrent newly setup interrupts.
The alloc/free protection of irq descriptors does not prevent the
above race, because it merily prevents interrupt descriptors from
going away or changing concurrently.
Prevent this by moving the call to setup_vector_irq() into the
vector_lock held region which protects set_cpu_online():
cpu N cpu M
native_cpu_up device_shutdown
do_boot_cpu free_msi_irqs
start_secondary arch_teardown_msi_irqs
smp_callin default_teardown_msi_irqs
lock(vector_lock) arch_teardown_msi_irq
setup_vector_irq()
__setup_vector_irq native_teardown_msi_irq
install vectors destroy_irq
set_cpu_online
unlock(vector_lock)
lock(vector_lock)
__clear_irq_vector
unlock(vector_lock)
So cpu M either sees the cpu N online before clearing the vector or
cpu N installs the vectors after cpu M has cleared it.
Reported-by: xiao jin <jin.xiao@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Link: http://lkml.kernel.org/r/20150705171102.141898931@linutronix.de
As we alloc pages with GFP_KERNEL in init_espfix_ap() which is
called before we enable local irqs, so the lockdep sub-system
would (correctly) trigger a warning about the potentially
blocking API.
So we allocate them on the boot CPU side when the secondary CPU is
brought up by the boot CPU, and hand them over to the secondary
CPU.
And we use alloc_pages_node() with the secondary CPU's node, to
make sure the espfix stack is NUMA-local to the CPU that is
going to use it.
Signed-off-by: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Cc: <bp@alien8.de>
Cc: <luto@amacapital.net>
Cc: <luto@kernel.org>
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/c97add2670e9abebb90095369f0cfc172373ac94.1435824469.git.zhugh.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
