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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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676e8cf70c
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
26 lines
670 B
C
26 lines
670 B
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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#ifndef _LINUX_LIVEPATCH_SCHED_H_
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#define _LINUX_LIVEPATCH_SCHED_H_
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#include <linux/jump_label.h>
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#include <linux/sched.h>
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#ifdef CONFIG_LIVEPATCH
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void __klp_sched_try_switch(void);
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DECLARE_STATIC_KEY_FALSE(klp_sched_try_switch_key);
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static __always_inline void klp_sched_try_switch(struct task_struct *curr)
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{
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if (static_branch_unlikely(&klp_sched_try_switch_key) &&
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READ_ONCE(curr->__state) & TASK_FREEZABLE)
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__klp_sched_try_switch();
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}
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#else /* !CONFIG_LIVEPATCH */
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static inline void klp_sched_try_switch(struct task_struct *curr) {}
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#endif /* CONFIG_LIVEPATCH */
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#endif /* _LINUX_LIVEPATCH_SCHED_H_ */
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