linux/kernel/livepatch
Josh Poimboeuf e3ff7c609f livepatch,sched: Add livepatch task switching to cond_resched()
There have been reports [1][2] of live patches failing to complete
within a reasonable amount of time due to CPU-bound kthreads.

Fix it by patching tasks in cond_resched().

There are four different flavors of cond_resched(), depending on the
kernel configuration.  Hook into all of them.

A more elegant solution might be to use a preempt notifier.  However,
non-ORC unwinders can't unwind a preempted task reliably.

[1] https://lore.kernel.org/lkml/20220507174628.2086373-1-song@kernel.org/
[2] https://lkml.kernel.org/lkml/20230120-vhost-klp-switching-v1-0-7c2b65519c43@kernel.org

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Link: https://lore.kernel.org/r/4ae981466b7814ec221014fc2554b2f86f3fb70b.1677257135.git.jpoimboe@kernel.org
2023-03-22 17:09:28 +01:00
..
core.c livepatch,sched: Add livepatch task switching to cond_resched() 2023-03-22 17:09:28 +01:00
core.h livepatch: Keep replaced patches until post_patch callback is called 2019-11-01 13:08:08 +01:00
Kconfig livepatch: Use the default ftrace_ops instead of REGS when ARGS is available 2020-11-13 12:15:28 -05:00
Makefile livepatch: Basic API to track system state changes 2019-11-01 13:08:14 +01:00
patch.c ftrace: rename ftrace_instruction_pointer_set() -> ftrace_regs_set_instruction_pointer() 2022-11-18 13:56:41 +00:00
patch.h livepatch: Remove Nop structures when unused 2019-01-11 20:51:24 +01:00
shadow.c Documentation: livepatch: Add livepatch API page 2021-12-23 11:35:53 +01:00
state.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
state.h livepatch: Allow to distinguish different version of system state changes 2019-11-01 13:08:19 +01:00
transition.c livepatch,sched: Add livepatch task switching to cond_resched() 2023-03-22 17:09:28 +01:00
transition.h livepatch: Remove signal sysfs attribute 2019-01-16 22:09:33 +01:00