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Thomas Gleixner 53f408cad0 hrtimers: Push pending hrtimers away from outgoing CPU earlier
[ Upstream commit 5c0930ccaa ]

2b8272ff4a ("cpu/hotplug: Prevent self deadlock on CPU hot-unplug")
solved the straight forward CPU hotplug deadlock vs. the scheduler
bandwidth timer. Yu discovered a more involved variant where a task which
has a bandwidth timer started on the outgoing CPU holds a lock and then
gets throttled. If the lock required by one of the CPU hotplug callbacks
the hotplug operation deadlocks because the unthrottling timer event is not
handled on the dying CPU and can only be recovered once the control CPU
reaches the hotplug state which pulls the pending hrtimers from the dead
CPU.

Solve this by pushing the hrtimers away from the dying CPU in the dying
callbacks. Nothing can queue a hrtimer on the dying CPU at that point because
all other CPUs spin in stop_machine() with interrupts disabled and once the
operation is finished the CPU is marked offline.

Reported-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Liu Tie <liutie4@huawei.com>
Link: https://lore.kernel.org/r/87a5rphara.ffs@tglx
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-13 18:44:56 +01:00
arch x86/xen: fix percpu vcpu_info allocation 2023-12-08 08:52:25 +01:00
block block: update the stable_writes flag in bdev_add 2023-12-03 07:33:03 +01:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: pcrypt - Fix hungtask for PADATA_RESET 2023-11-28 17:19:42 +00:00
Documentation leds: class: Don't expose color sysfs entry 2023-12-08 08:52:15 +01:00
drivers scsi: sd: Fix sshdr use in sd_suspend_common() 2023-12-13 18:44:55 +01:00
fs btrfs: fix 64bit compat send ioctl arguments not initializing version member 2023-12-08 08:52:20 +01:00
include hrtimers: Push pending hrtimers away from outgoing CPU earlier 2023-12-13 18:44:56 +01:00
init proc: sysctl: prevent aliased sysctls from getting passed to init 2023-11-28 17:19:57 +00:00
io_uring io_uring/kbuf: recycle freed mapped buffer ring entries 2023-12-08 08:52:21 +01:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel hrtimers: Push pending hrtimers away from outgoing CPU earlier 2023-12-13 18:44:56 +01:00
lib parisc: Drop the HP-UX ENOSYM and EREMOTERELEASE error codes 2023-12-08 08:52:20 +01:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm filemap: add a per-mapping stable writes flag 2023-12-03 07:33:03 +01:00
net Revert "wifi: cfg80211: fix CQM for non-range use" 2023-12-11 10:40:17 +01:00
rust rust: docs: fix logo replacement 2023-10-19 16:40:00 +02:00
samples samples/bpf: syscall_tp_user: Fix array out-of-bound access 2023-11-28 17:19:48 +00:00
scripts scripts/gdb/vmalloc: disable on no-MMU 2023-11-28 17:20:05 +00:00
security apparmor: Fix regression in mount mediation 2023-11-28 17:20:07 +00:00
sound ALSA: hda/realtek: Add supported ALC257 for ChromeOS 2023-12-08 08:52:16 +01:00
tools selftests/net: mptcp: fix uninitialized variable warnings 2023-12-08 08:52:22 +01:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Char/Misc driver fixes for 6.6-final 2023-10-28 07:51:27 -10:00
Makefile Linux 6.6.6 2023-12-11 10:40:17 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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.

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.