linux/arch/ia64/kernel
Arnd Bergmann 796130b1de ia64: fix timer cleanup regression
A cleanup patch from my legacy timer series broke ia64 and led
to RCU stall errors and a fast system clock:

[  909.360108] INFO: task systemd-sysv-ge:200 blocked for more than 127 seconds.
[  909.360108]       Not tainted 5.10.0+ #130
[  909.360108] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  909.360108] task:systemd-sysv-ge state:D stack:    0 pid:  200 ppid:   189 flags:0x00000000
[  909.364108]
[  909.364108] Call Trace:
[  909.364423]  [<a00000010109b210>] __schedule+0x890/0x21e0
[  909.364423]                                 sp=e0000100487d7b70 bsp=e0000100487d1748
[  909.368423]  [<a00000010109cc00>] schedule+0xa0/0x240
[  909.368423]                                 sp=e0000100487d7b90 bsp=e0000100487d16e0
[  909.368558]  [<a00000010109ce70>] io_schedule+0x70/0xa0
[  909.368558]                                 sp=e0000100487d7b90 bsp=e0000100487d16c0
[  909.372290]  [<a00000010109e1c0>] bit_wait_io+0x20/0xe0
[  909.372290]                                 sp=e0000100487d7b90 bsp=e0000100487d1698
[  909.374168] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[  909.376290]  [<a00000010109d860>] __wait_on_bit+0xc0/0x1c0
[  909.376290]                                 sp=e0000100487d7b90 bsp=e0000100487d1648
[  909.374168] rcu:     3-....: (2 ticks this GP) idle=19e/1/0x4000000000000002 softirq=1581/1581 fqs=2
[  909.374168]  (detected by 0, t=5661 jiffies, g=1089, q=3)
[  909.376290]  [<a00000010109da80>] out_of_line_wait_on_bit+0x120/0x140
[  909.376290]                                 sp=e0000100487d7b90 bsp=e0000100487d1610
[  909.374168] Task dump for CPU 3:
[  909.374168] task:khungtaskd      state:R  running task

Revert most of my patch to make this work again, including the extra
update_process_times()/profile_tick() and the local_irq_enable() in the
loop that I expected not to be needed here.

I have not found out exactly what goes wrong, and would suggest that
someone with hardware access tries to convert this code into a singleshot
clockevent driver, which should give better behavior in all cases.

Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Fixes: 2b49ddcef2 ("ia64: convert to legacy_timer_tick")
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-01-12 17:01:42 +01:00
..
syscalls epoll: wire up syscall epoll_pwait2 2020-12-19 11:18:38 -08:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
acpi-ext.c
acpi.c ACPI/sleep: Convert acpi_wakeup_address into a function 2019-12-10 10:15:48 +01:00
asm-offsets.c
audit.c
brl_emu.c
crash.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
crash_dump.c
cyclone.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
dma-mapping.c dma-mapping: split <linux/dma-mapping.h> 2020-10-06 07:07:03 +02:00
efi.c mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
efi_stub.S
elfcore.c
entry.h
entry.S ia64: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args 2020-06-23 10:49:56 +02:00
err_inject.c
esi.c efi/ia64: Use existing helpers to locate ESI table 2020-02-23 21:59:42 +01:00
esi_stub.S
fsys.S
fsyscall_gtod_data.h
ftrace.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
gate-data.S
gate.lds.S
gate.S
head.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
ia64_ksyms.c ia64: fix min_low_pfn/max_low_pfn build errors 2020-09-01 19:34:11 +03:00
iosapic.c locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header 2020-08-06 16:13:13 +02:00
irq.c locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header 2020-08-06 16:13:13 +02:00
irq.h ia64: replace setup_irq() by request_irq() 2020-03-13 15:21:28 -07:00
irq_ia64.c ia64: Remove perfmon 2020-09-11 09:34:32 -07:00
irq_lsapic.c
ivt.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
kprobes.c ia64: kprobes: Use generic kretprobe trampoline handler 2020-09-08 11:52:33 +02:00
machine_kexec.c
Makefile ia64: fix build error with !COREDUMP 2020-10-18 09:27:09 -07:00
Makefile.gate
mca.c kernel: rename show_stack_loglvl() => show_stack() 2020-06-09 09:39:13 -07:00
mca_asm.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
mca_drv.c
mca_drv.h
mca_drv_asm.S
minstate.h
module.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
msi_ia64.c
nr-irqs.c
numa.c
pal.S
palinfo.c
patch.c
pci-dma.c
perfmon_default_smpl.c
perfmon_generic.h
perfmon_itanium.h
perfmon_mckinley.h
perfmon_montecito.h
process.c tif-task_work.arch-2020-12-14 2020-12-16 12:33:35 -08:00
ptrace.c [ia64] ptrace_[sg]etregs(): use access_elf_reg() instead of access_uarea() 2020-10-25 20:03:04 -04:00
relocate_kernel.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
sal.c locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header 2020-08-06 16:13:13 +02:00
salinfo.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
setup.c locking, arch/ia64: Reduce <asm/smp.h> header dependencies by moving XTP bits into the new <asm/xtp.h> header 2020-08-06 16:13:13 +02:00
sigframe.h
signal.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
smp.c A set of locking fixes and updates: 2020-08-10 19:07:44 -07:00
smpboot.c ia64: Remove perfmon 2020-09-11 09:34:32 -07:00
stacktrace.c
sys_ia64.c
time.c ia64: fix timer cleanup regression 2021-01-12 17:01:42 +01:00
topology.c
traps.c
unaligned.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
uncached.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
unwind.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
unwind_decoder.c
unwind_i.h ia64: kernel: unwind_i.h: Replace zero-length array with flexible-array 2020-06-15 23:08:31 -05:00
vmlinux.lds.S vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG 2020-09-01 09:50:35 +02:00