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| author | Peter Zijlstra <peterz@infradead.org> | 2025-05-09 14:36:59 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-05-14 14:16:24 +0300 |
| commit | 676e8cf70cb0533e1118e29898c9a9c33ae3a10f (patch) | |
| tree | ea7646aca88d44c671755b5d205984ffad12a783 /include/linux/livepatch_sched.h | |
| parent | b7ca5743a2604156d6083b88cefacef983f3a3a6 (diff) | |
| download | linux-676e8cf70cb0533e1118e29898c9a9c33ae3a10f.tar.xz | |
sched,livepatch: Untangle cond_resched() and live-patching
With the goal of deprecating / removing VOLUNTARY preempt, live-patch
needs to stop relying on cond_resched() to make forward progress.
Instead, rely on schedule() with TASK_FREEZABLE set. Just like
live-patching, the freezer needs to be able to stop tasks in a safe /
known state.
[bigeasy: use likely() in __klp_sched_try_switch() and update comments]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Tested-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20250509113659.wkP_HJ5z@linutronix.de
Diffstat (limited to 'include/linux/livepatch_sched.h')
| -rw-r--r-- | include/linux/livepatch_sched.h | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/include/linux/livepatch_sched.h b/include/linux/livepatch_sched.h index 013794fb5da0..065c185f2763 100644 --- a/include/linux/livepatch_sched.h +++ b/include/linux/livepatch_sched.h @@ -3,27 +3,23 @@ #define _LINUX_LIVEPATCH_SCHED_H_ #include <linux/jump_label.h> -#include <linux/static_call_types.h> +#include <linux/sched.h> #ifdef CONFIG_LIVEPATCH void __klp_sched_try_switch(void); -#if !defined(CONFIG_PREEMPT_DYNAMIC) || !defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) - DECLARE_STATIC_KEY_FALSE(klp_sched_try_switch_key); -static __always_inline void klp_sched_try_switch(void) +static __always_inline void klp_sched_try_switch(struct task_struct *curr) { - if (static_branch_unlikely(&klp_sched_try_switch_key)) + if (static_branch_unlikely(&klp_sched_try_switch_key) && + READ_ONCE(curr->__state) & TASK_FREEZABLE) __klp_sched_try_switch(); } -#endif /* !CONFIG_PREEMPT_DYNAMIC || !CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */ - #else /* !CONFIG_LIVEPATCH */ -static inline void klp_sched_try_switch(void) {} -static inline void __klp_sched_try_switch(void) {} +static inline void klp_sched_try_switch(struct task_struct *curr) {} #endif /* CONFIG_LIVEPATCH */ #endif /* _LINUX_LIVEPATCH_SCHED_H_ */ |