The following commit has been merged into the sched/core branch of tip: Commit-ID: 40607ee97e4eec5655cc0f76a720bdc4c63a6434 Gitweb: https://git.kernel.org/tip/40607ee97e4eec5655cc0f76a720bdc4c63a6434 Author: Peter Zijlstra (Intel) <pet...@infradead.org> AuthorDate: Mon, 18 Jan 2021 15:12:22 +01:00 Committer: Ingo Molnar <mi...@kernel.org> CommitterDate: Wed, 17 Feb 2021 14:12:42 +01:00
preempt/dynamic: Provide irqentry_exit_cond_resched() static call Provide static call to control IRQ preemption (called in CONFIG_PREEMPT) so that we can override its behaviour when preempt= is overriden. Since the default behaviour is full preemption, its call is initialized to provide IRQ preemption when preempt= isn't passed. Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Frederic Weisbecker <frede...@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Ingo Molnar <mi...@kernel.org> Link: https://lkml.kernel.org/r/20210118141223.123667-8-frede...@kernel.org --- include/linux/entry-common.h | 4 ++++ kernel/entry/common.c | 10 +++++++++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index a104b29..883acef 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -2,6 +2,7 @@ #ifndef __LINUX_ENTRYCOMMON_H #define __LINUX_ENTRYCOMMON_H +#include <linux/static_call_types.h> #include <linux/tracehook.h> #include <linux/syscalls.h> #include <linux/seccomp.h> @@ -454,6 +455,9 @@ irqentry_state_t noinstr irqentry_enter(struct pt_regs *regs); * Conditional reschedule with additional sanity checks. */ void irqentry_exit_cond_resched(void); +#ifdef CONFIG_PREEMPT_DYNAMIC +DECLARE_STATIC_CALL(irqentry_exit_cond_resched, irqentry_exit_cond_resched); +#endif /** * irqentry_exit - Handle return from exception that used irqentry_enter() diff --git a/kernel/entry/common.c b/kernel/entry/common.c index f9d491b..f09cae3 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -385,6 +385,9 @@ void irqentry_exit_cond_resched(void) preempt_schedule_irq(); } } +#ifdef CONFIG_PREEMPT_DYNAMIC +DEFINE_STATIC_CALL(irqentry_exit_cond_resched, irqentry_exit_cond_resched); +#endif noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) { @@ -411,8 +414,13 @@ noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) } instrumentation_begin(); - if (IS_ENABLED(CONFIG_PREEMPTION)) + if (IS_ENABLED(CONFIG_PREEMPTION)) { +#ifdef CONFIG_PREEMT_DYNAMIC + static_call(irqentry_exit_cond_resched)(); +#else irqentry_exit_cond_resched(); +#endif + } /* Covers both tracing and lockdep */ trace_hardirqs_on(); instrumentation_end();
