A mirror of the official Linux kernel repository just in case
Go to file
Shilpasri G Bhat c0f7f5b6c6 cpufreq: powernv: Fix hardlockup due to synchronous smp_call in timer interrupt
gpstate_timer_handler() uses synchronous smp_call to set the pstate
on the requested core. This causes the below hard lockup:

  smp_call_function_single+0x110/0x180 (unreliable)
  smp_call_function_any+0x180/0x250
  gpstate_timer_handler+0x1e8/0x580
  call_timer_fn+0x50/0x1c0
  expire_timers+0x138/0x1f0
  run_timer_softirq+0x1e8/0x270
  __do_softirq+0x158/0x3e4
  irq_exit+0xe8/0x120
  timer_interrupt+0x9c/0xe0
  decrementer_common+0x114/0x120
  -- interrupt: 901 at doorbell_global_ipi+0x34/0x50
  LR = arch_send_call_function_ipi_mask+0x120/0x130
  arch_send_call_function_ipi_mask+0x4c/0x130
  smp_call_function_many+0x340/0x450
  pmdp_invalidate+0x98/0xe0
  change_huge_pmd+0xe0/0x270
  change_protection_range+0xb88/0xe40
  mprotect_fixup+0x140/0x340
  SyS_mprotect+0x1b4/0x350
  system_call+0x58/0x6c

One way to avoid this is removing the smp-call. We can ensure that the
timer always runs on one of the policy-cpus. If the timer gets
migrated to a cpu outside the policy then re-queue it back on the
policy->cpus. This way we can get rid of the smp-call which was being
used to set the pstate on the policy->cpus.

Fixes: 7bc54b652f ("timers, cpufreq/powernv: Initialize the gpstate timer as pinned")
Cc: stable@vger.kernel.org # v4.8+
Reported-by: Nicholas Piggin <npiggin@gmail.com>
Reported-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-27 16:16:10 +10:00
arch powerpc: Fix smp_send_stop NMI IPI handling 2018-04-25 20:38:08 +10:00
block blk-mq: Revert "blk-mq: reimplement blk_mq_hw_queue_mapped" 2018-04-11 07:59:15 -06:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
Documentation Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal 2018-04-20 10:56:32 -07:00
drivers cpufreq: powernv: Fix hardlockup due to synchronous smp_call in timer interrupt 2018-04-27 16:16:10 +10:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs various SMB3/CIFS fixes for stable 4.17-rc1 2018-04-22 12:13:04 -07:00
include exynos, i915, vc4, amdgpu fixes 2018-04-22 17:14:29 -07:00
init Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-15 16:12:35 -07:00
ipc ipc/shm: fix use-after-free of shm file via remap_file_pages() 2018-04-13 17:10:27 -07:00
kernel Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-22 10:49:02 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-20 09:34:39 -07:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
mm mm/filemap.c: fix NULL pointer in page_cache_tree_insert() 2018-04-20 17:18:36 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-04-20 09:34:39 -07:00
samples Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching 2018-04-20 08:51:55 -07:00
scripts Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
security + Features 2018-04-13 15:38:53 -07:00
sound sound fixes for 4.17-rc2 2018-04-21 10:32:16 -07:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-22 10:17:01 -07:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt KVM/ARM updates for v4.17 2018-03-28 16:09:09 +02:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge candidates for 4.17 merge window 2018-04-06 17:35:43 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2018-04-21 21:11:05 -07:00
Makefile Linux 4.17-rc2 2018-04-22 19:20:09 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.