linux/arch/powerpc/kernel
Anton Blanchard 8050936caf powerpc: irq work racing with timer interrupt can result in timer interrupt hang
I am seeing an issue where a CPU running perf eventually hangs.
Traces show timer interrupts happening every 4 seconds even
when a userspace task is running on the CPU. /proc/timer_list
also shows pending hrtimers have not run in over an hour,
including the scheduler.

Looking closer, decrementers_next_tb is getting set to
0xffffffffffffffff, and at that point we will never take
a timer interrupt again.

In __timer_interrupt() we set decrementers_next_tb to
0xffffffffffffffff and rely on ->event_handler to update it:

        *next_tb = ~(u64)0;
        if (evt->event_handler)
                evt->event_handler(evt);

In this case ->event_handler is hrtimer_interrupt. This will eventually
call back through the clockevents code with the next event to be
programmed:

static int decrementer_set_next_event(unsigned long evt,
                                      struct clock_event_device *dev)
{
        /* Don't adjust the decrementer if some irq work is pending */
        if (test_irq_work_pending())
                return 0;
        __get_cpu_var(decrementers_next_tb) = get_tb_or_rtc() + evt;

If irq work came in between these two points, we will return
before updating decrementers_next_tb and we never process a timer
interrupt again.

This looks to have been introduced by 0215f7d8c5 (powerpc: Fix races
with irq_work). Fix it by removing the early exit and relying on
code later on in the function to force an early decrementer:

       /* We may have raced with new irq work */
       if (test_irq_work_pending())
               set_dec(1);

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-05-12 14:29:28 +10:00
..
vdso32 powerpc/booke64: Use SPRG7 for VDSO 2014-03-19 19:57:14 -05:00
vdso64 powerpc/booke64: Use SPRG7 for VDSO 2014-03-19 19:57:14 -05:00
.gitignore
align.c powerpc: Add lq/stq emulation 2014-04-09 12:53:28 +10:00
asm-offsets.c powerpc/booke64: Use SPRG7 for VDSO 2014-03-19 19:57:14 -05:00
audit.c
btext.c powerpc/btext: Fix CONFIG_PPC_EARLY_DEBUG_BOOTX on ppc32 2013-08-27 16:01:23 +10:00
cacheinfo.c powerpc/pseries: Update dynamic cache nodes for suspend/resume operation 2014-03-07 15:54:49 +11:00
cacheinfo.h
compat_audit.c
cpu_setup_6xx.S
cpu_setup_44x.S
cpu_setup_a2.S powerpc: Enforce usage of RA 0-R31 where possible 2012-07-10 19:18:35 +10:00
cpu_setup_fsl_booke.S powerpc/85xx: add hardware automatically enter pw20 state 2014-01-07 19:40:28 -06:00
cpu_setup_pa6t.S
cpu_setup_power.S powerpc/ppc64: Do not turn AIL (reloc-on interrupts) too early 2014-04-07 10:33:15 +10:00
cpu_setup_ppc970.S
cputable.c powerpc: Add a cpu feature CPU_FTR_PMAO_BUG 2014-03-24 09:48:24 +11:00
crash_dump.c powerpc/crashdump : Fix page frame number check in copy_oldmem_page 2014-02-28 18:06:25 +11:00
crash.c powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
dbell.c powerpc: Add accounting for Doorbell interrupts 2013-04-18 15:59:55 +10:00
dma-iommu.c powerpc/iommu: Update the generic code to use dynamic iommu page sizes 2013-12-30 14:17:19 +11:00
dma-swiotlb.c powerpc/swiotlb: Enable at early stage and disable if not necessary 2012-09-12 14:57:09 -05:00
dma.c powerpc/powernv: Add iommu DMA bypass support for IODA2 2014-02-11 16:07:37 +11:00
eeh_cache.c powerpc/eeh: Remove reference to PCI device 2013-07-24 14:18:46 +10:00
eeh_dev.c powerpc/eeh: Move common part to kernel directory 2013-06-20 17:05:35 +10:00
eeh_driver.c powerpc: eeh: Fixup the brown paperbag fallout of the "cleanup" 2014-03-05 00:13:33 +01:00
eeh_event.c powerpc/eeh: More accurate log 2013-11-21 10:33:36 +11:00
eeh_pe.c powerpc/eeh: Add restore_config operation 2014-01-15 13:46:46 +11:00
eeh_sysfs.c powerpc/eeh: Introdce flag to protect sysfs 2013-07-24 14:18:49 +10:00
eeh.c powerpc/eeh: Disable EEH on reboot 2014-02-17 11:19:39 +11:00
entry_32.S powerpc/32bit:Store temporary result in r0 instead of r8 2013-06-01 08:29:27 +10:00
entry_64.S powerpc: Don't corrupt transactional state when using FP/VMX in kernel 2014-01-15 13:59:11 +11:00
epapr_hcalls.S powerpc: Add paravirt idle loop for 64-bit Book-E 2013-03-13 14:19:36 -05:00
epapr_paravirt.c powerpc: add explicit OF includes 2013-10-09 20:04:11 -05:00
exceptions-64e.S powerpc/booke64: Critical and machine check exception support 2014-03-19 19:57:27 -05:00
exceptions-64s.S powerpc: Remove dead code in sycall entry 2014-04-09 12:53:11 +10:00
fadump.c mm/ppc: use common help functions to free reserved pages 2013-04-29 15:54:30 -07:00
firmware.c
fpu.S powerpc: Don't corrupt transactional state when using FP/VMX in kernel 2014-01-15 13:59:11 +11:00
fsl_booke_entry_mapping.S powerpc: enable the relocatable support for the fsl booke 32bit kernel 2014-01-09 17:52:16 -06:00
ftrace.c Most of the changes were largely clean ups, and some documentation. 2014-04-03 10:26:31 -07:00
head_8xx.S powerpc/8xx: Fixing issue with CONFIG_PIN_TLB 2013-10-28 21:11:21 -05:00
head_32.S
head_40x.S powerpc: Remove the empty giveup_fpu() function on 32bit kernel 2013-08-14 14:59:50 +10:00
head_44x.S powerpc: Remove the empty giveup_fpu() function on 32bit kernel 2013-08-14 14:59:50 +10:00
head_64.S powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
head_booke.h powerpc: Fix interrupt range check on debug exception 2013-05-02 10:31:01 +10:00
head_fsl_booke.S powerpc/fsl_booke: smp support for booting a relocatable kernel above 64M 2014-01-09 17:52:18 -06:00
hw_breakpoint.c powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
ibmebus.c PPC: ibmebus: convert bus code to use bus_groups 2013-09-26 15:49:42 -07:00
idle_6xx.S powerpc: Use CURRENT_THREAD_INFO instead of open coded assembly 2012-07-11 14:18:22 +10:00
idle_book3e.S powerpc: Add paravirt idle loop for 64-bit Book-E 2013-03-13 14:19:36 -05:00
idle_e500.S powerpc: Use CURRENT_THREAD_INFO instead of open coded assembly 2012-07-11 14:18:22 +10:00
idle_power4.S powerpc: Use CURRENT_THREAD_INFO instead of open coded assembly 2012-07-11 14:18:22 +10:00
idle_power7.S powerpc/powernv: Add OPAL call to resync timebase on wakeup 2014-03-05 15:56:54 +11:00
idle.c powerpc/idle: Convert use of typedef ctl_table to struct ctl_table 2013-07-01 11:10:35 +10:00
io-workarounds.c powerpc: Better split CONFIG_PPC_INDIRECT_PIO and CONFIG_PPC_INDIRECT_MMIO 2013-08-14 14:57:50 +10:00
io.c powerpc/powernv: Add PIO accessors for Power8 LPC bus 2013-08-14 14:58:08 +10:00
iomap.c powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
iommu.c powerpc/powernv: Add iommu DMA bypass support for IODA2 2014-02-11 16:07:37 +11:00
irq.c powerpc: Irq: Use generic_handle_irq 2014-03-04 17:37:52 +01:00
isa-bridge.c POWERPC: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
jump_label.c
kgdb.c powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
kprobes.c doc: typo on word accounting in kprobes.c in mutliple architectures 2013-10-14 15:46:39 +02:00
kvm_emul.S KVM: PPC: Not optimizing MSR_CE and MSR_ME with paravirt. 2012-05-30 11:43:11 +02:00
kvm.c kvm/powerpc: rename kvm_hypercall() to epapr_hypercall() 2014-01-09 10:14:56 +01:00
l2cr_6xx.S
legacy_serial.c powerpc/legacy_serial: Fix incorrect placement of __initdata tag 2013-10-11 16:48:59 +11:00
machine_kexec_32.c
machine_kexec_64.c powerpc: Fix endian issues in kexec and crash dump code 2014-02-11 11:24:52 +11:00
machine_kexec.c powerpc: Fix endian issues in kexec and crash dump code 2014-02-11 11:24:52 +11:00
Makefile clk: mpc5xxx: switch to COMMON_CLK, retire PPC_CLOCK 2014-01-12 18:53:04 +01:00
mce_power.c powerpc/book3s: Recover from MC in sapphire on SCOM read via MMIO. 2014-03-07 15:52:10 +11:00
mce.c powerpc/book3s: Recover from MC in sapphire on SCOM read via MMIO. 2014-03-07 15:52:10 +11:00
misc_32.S powerpc: Set the correct ksp_limit on ppc32 when switching to irq stack 2014-02-17 11:19:34 +11:00
misc_64.S Merge branch 'merge' into next 2013-12-30 15:19:31 +11:00
misc.S powerpc: switch to generic sys_execve()/kernel_execve() 2012-09-30 23:35:51 -04:00
module_32.c powerpc: Move local setup.h declarations to arch includes 2013-10-30 16:00:31 +11:00
module_64.c powerpc: Move local setup.h declarations to arch includes 2013-10-30 16:00:31 +11:00
module.c powerpc: Move local setup.h declarations to arch includes 2013-10-30 16:00:31 +11:00
msi.c
nvram_64.c arch/powerpc/kernel: Use %12.12s instead of %12s to avoid memory overflow 2013-11-25 11:50:57 +11:00
of_platform.c powerpc/eeh: Fix crash when adding a device in a slot with DDW 2013-01-10 17:01:58 +11:00
paca.c powerpc/ppc64: Gracefully handle early interrupts 2014-04-07 10:33:15 +10:00
pci_32.c powerpc/pci: Support per-aperture memory offset 2013-05-06 13:40:40 +10:00
pci_64.c powerpc/PCI: Fix NULL dereference in sys_pciconfig_iobase() list traversal 2014-04-14 16:33:49 -06:00
pci_dn.c powerpc: Make PCI device node device tree accesses endian safe 2013-08-14 15:33:31 +10:00
pci_of_scan.c PCI: Convert pcibios_resource_to_bus() to take a pci_bus, not a pci_dev 2013-12-21 10:06:10 -07:00
pci-common.c PCI: Convert pcibios_resource_to_bus() to take a pci_bus, not a pci_dev 2013-12-21 10:06:10 -07:00
pci-hotplug.c powerpc/pci: Partial tree hotplug support 2013-07-24 14:18:48 +10:00
pmc.c
ppc32.h powerpc: switch to generic old sigaction() 2013-02-03 18:16:10 -05:00
ppc_ksyms.c powerpc: Export flush_icache_range 2014-04-28 13:08:46 +10:00
ppc_save_regs.S
proc_powerpc.c proc_powerpc: switch to fixed_size_llseek() 2013-06-29 12:57:50 +04:00
process.c powerpc/tm: Disable IRQ in tm_recheckpoint 2014-04-07 10:33:13 +10:00
prom_init_check.sh powerpc/pmac: Early debug output on screen on 64-bit macs 2013-08-14 14:57:40 +10:00
prom_init.c powerpc: Check return value of instance-to-package OF call 2014-01-13 09:49:17 +11:00
prom_parse.c powerpc: of_parse_dma_window should take a __be32 *dma_window 2013-08-14 15:33:26 +10:00
prom.c powerpc/prom: early_init_dt_scan_cpus() updates cpu features only once 2014-04-07 10:33:14 +10:00
ptrace32.c powerpc: move debug registers in a structure 2013-10-18 18:44:49 -05:00
ptrace.c powerpc: PTRACE_PEEKUSR always returns FPR0 2013-12-13 15:48:33 +11:00
reloc_32.S powerpc: Don't flush/invalidate the d/icache for an unknown relocation type 2013-07-01 11:10:34 +10:00
reloc_64.S powerpc: Align p_dyn, p_rela and p_st symbols 2014-03-07 13:50:19 +11:00
rtas_flash.c powerpc: Fix error return in rtas_flash module init 2014-04-28 16:32:07 +10:00
rtas_pci.c powerpc/kernel: Fix endian issue in rtas_pci 2013-10-11 16:50:22 +11:00
rtas-proc.c
rtas-rtc.c
rtas.c powerpc/le: Enable RTAS events support 2014-04-07 10:33:12 +10:00
rtasd.c powerpc/le: Enable RTAS events support 2014-04-07 10:33:12 +10:00
setup_32.c powerpc: Make boot_cpuid common between 32 and 64-bit 2014-04-07 10:33:14 +10:00
setup_64.c powerpc: Don't try to set LPCR unless we're in hypervisor mode 2014-04-12 17:58:48 -07:00
setup-common.c powerpc: Make boot_cpuid common between 32 and 64-bit 2014-04-07 10:33:14 +10:00
signal_32.c powerpc/tm: Disable IRQ in tm_recheckpoint 2014-04-07 10:33:13 +10:00
signal_64.c powerpc/tm: Disable IRQ in tm_recheckpoint 2014-04-07 10:33:13 +10:00
signal.c powerpc: Don't corrupt transactional state when using FP/VMX in kernel 2014-01-15 13:59:11 +11:00
signal.h powerpc/tm: Fix userspace stack corruption on signal delivery for active transactions 2013-06-01 08:29:23 +10:00
smp-tbsync.c powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
smp.c powerpc: Implement tick broadcast IPI as a fixed IPI message 2014-03-05 15:55:04 +11:00
stacktrace.c
suspend.c
swsusp_32.S
swsusp_64.c
swsusp_asm64.S powerpc: Only save/restore SDR1 if in hypervisor mode 2013-10-31 12:37:29 +11:00
swsusp_booke.S powerpc/fsl-booke: Use SPRN_SPRGn rather than mfsprg/mtsprg 2014-01-07 19:06:03 -06:00
swsusp.c
sys_ppc32.c unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE 2013-05-09 13:46:38 -04:00
syscalls.c powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
sysfs.c powerpc, sysfs: Fix CPU hotplug callback registration 2014-03-20 13:43:42 +01:00
systbl_chk.c
systbl_chk.sh
systbl.S
tau_6xx.c
time.c powerpc: irq work racing with timer interrupt can result in timer interrupt hang 2014-05-12 14:29:28 +10:00
tm.S powerpc/tm: Disable IRQ in tm_recheckpoint 2014-04-07 10:33:13 +10:00
traps.c powerpc: Add lq/stq emulation 2014-04-09 12:53:28 +10:00
udbg_16550.c powerpc/wsp: Fix early debug build 2013-08-16 10:59:27 +10:00
udbg.c powerpc: Add a configuration option for early BootX/OpenFirmware debug 2013-06-20 16:55:12 +10:00
uprobes.c uprobes/powerpc: Kill arch_uprobe->ainsn 2013-11-20 16:31:01 +01:00
vdso.c powerpc/booke64: Use SPRG7 for VDSO 2014-03-19 19:57:14 -05:00
vecemu.c powerpc: Put FP/VSX and VR state into structures 2013-10-11 17:26:49 +11:00
vector.S powerpc: Don't corrupt transactional state when using FP/VMX in kernel 2014-01-15 13:59:11 +11:00
vio.c powerpc: Revert c6102609 and replace it with the correct fix for vio dma mask setting 2014-03-07 15:50:12 +11:00
vmlinux.lds.S powerpc/modules: Module CRC relocation fix causes perf issues 2013-07-24 14:18:43 +10:00