linux/arch/x86/kernel
Peter Zijlstra 3896c329df x86, tsc: Fix cpufreq lockup
Mauro reported that his AMD X2 using the powernow-k8 cpufreq driver
locked up when doing cpu hotplug.

Because we called set_cyc2ns_scale() from the time_cpufreq_notifier()
unconditionally, it gets called multiple times for each freq change,
instead of only the once, when the tsc_khz value actually changes.

Because it gets called more than once, we run out of cyc2ns data slots
and stall, waiting for a free one, but because we're half way offline,
there's no consumers to free slots.

By placing the call inside the condition that actually changes tsc_khz
we avoid superfluous calls and avoid the problem.

Reported-by: Mauro <registosites@hotmail.com>
Tested-by: Mauro <registosites@hotmail.com>
Fixes: 20d1c86a57 ("sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQs")
Cc: <stable@vger.kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Bin Gao <bin.gao@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-02 08:33:47 +02:00
..
acpi
apic nmi: provide the option to issue an NMI back trace to every cpu but current 2014-06-23 16:47:44 -07:00
cpu Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-12 20:03:47 -07:00
kprobes
.gitignore
Makefile Lots of tweaks, small fixes, optimizations, and some helper functions 2014-06-09 16:39:15 -07:00
alternative.c
amd_gart_64.c x86: enable DMA CMA with swiotlb 2014-06-04 16:53:57 -07:00
amd_nb.c
apb_timer.c
aperture_64.c
apm_32.c
asm-offsets.c
asm-offsets_32.c
asm-offsets_64.c
audit_64.c
bootflag.c
check.c
cpuid.c
crash.c
crash_dump_32.c
crash_dump_64.c
devicetree.c
doublefault.c
dumpstack.c
dumpstack_32.c
dumpstack_64.c
e820.c
early-quirks.c Merge commit '9e9a928eed8796a0a1aaed7e0b676db86ba84594' into drm-next 2014-06-05 20:28:59 +10:00
early_printk.c
entry_32.S x86_32, entry: Do syscall exit work on badsys (CVE-2014-4508) 2014-06-23 14:59:26 -07:00
entry_64.S Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-12 19:18:49 -07:00
espfix_64.c
ftrace.c ftrace/x86: Call text_ip_addr() instead of the duplicated code 2014-06-03 19:44:37 -04:00
head.c
head32.c
head64.c kernel/printk: use symbolic defines for console loglevels 2014-06-04 16:54:17 -07:00
head_32.S
head_64.S
hpet.c Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next 2014-06-05 08:05:29 -07:00
hw_breakpoint.c
i386_ksyms_32.c
i387.c
i8237.c
i8253.c
i8259.c
io_delay.c
ioport.c
iosf_mbi.c
irq.c Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-12 20:03:47 -07:00
irq_32.c
irq_64.c
irq_work.c
irqinit.c
jump_label.c
kdebugfs.c
kgdb.c
ksysfs.c
kvm.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-12 19:18:49 -07:00
kvmclock.c
ldt.c
machine_kexec_32.c
machine_kexec_64.c
mcount_64.S
mmconf-fam10h_64.c
module.c
mpparse.c
msr.c
nmi.c
nmi_selftest.c
paravirt-spinlocks.c
paravirt.c
paravirt_patch_32.c
paravirt_patch_64.c
pci-calgary_64.c
pci-dma.c arch/x86/kernel/pci-dma.c: fix dma_generic_alloc_coherent() when CONFIG_DMA_CMA is enabled 2014-06-04 16:53:57 -07:00
pci-iommu_table.c
pci-nommu.c
pci-swiotlb.c x86: enable DMA CMA with swiotlb 2014-06-04 16:53:57 -07:00
pcspeaker.c
perf_regs.c
preempt.S
probe_roms.c
process.c
process_32.c
process_64.c Merge branch 'perf/urgent' into perf/core, to resolve conflict and to prepare for new patches 2014-06-06 07:55:06 +02:00
ptrace.c
pvclock.c
quirks.c
reboot.c
reboot_fixups_32.c
relocate_kernel_32.S
relocate_kernel_64.S
resource.c
rtc.c
setup.c cma: add placement specifier for "cma=" kernel parameter 2014-06-04 16:53:57 -07:00
setup_percpu.c
signal.c x86_32, signal: Fix vdso rt_sigreturn 2014-06-23 15:54:42 -07:00
smp.c
smpboot.c Merge branch 'next' (accumulated 3.16 merge window patches) into master 2014-06-08 11:31:16 -07:00
stacktrace.c
step.c
sys_x86_64.c
syscall_32.c
syscall_64.c
sysfb.c
sysfb_efi.c
sysfb_simplefb.c
tboot.c
tce_64.c
test_nx.c
test_rodata.c
time.c
tls.c
tls.h
topology.c
trace_clock.c
tracepoint.c
traps.c x86/kprobes: Fix build errors and blacklist context_track_user 2014-06-14 09:07:44 +02:00
tsc.c x86, tsc: Fix cpufreq lockup 2014-07-02 08:33:47 +02:00
tsc_msr.c
tsc_sync.c
uprobes.c uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates 2014-06-05 16:21:57 +02:00
verify_cpu.S
vm86_32.c
vmlinux.lds.S
vsmp_64.c
vsyscall_64.c
vsyscall_emu_64.S
vsyscall_gtod.c
vsyscall_trace.h
x86_init.c
x8664_ksyms_64.c
xsave.c