Sebastian Andrzej Siewior
c7e8509657
BugLink: https://bugs.launchpad.net/bugs/2089700 perf_pending_irq() invokes perf_event_wakeup() and __perf_pending_irq(). The former is in charge of waking any tasks which waits to be woken up while the latter disables perf-events. The irq_work perf_pending_irq(), while this an irq_work, the callback is invoked in thread context on PREEMPT_RT. This is needed because all the waking functions (wake_up_all(), kill_fasync()) acquire sleep locks which must not be used with disabled interrupts. Disabling events, as done by __perf_pending_irq(), expects a hardirq context and disabled interrupts. This requirement is not fulfilled on PREEMPT_RT. Split functionality based on perf_event::pending_disable into irq_work named `pending_disable_irq' and invoke it in hardirq context on PREEMPT_RT. Rename the split out callback to perf_pending_disable(). Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Marco Elver <elver@google.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Link: https://lore.kernel.org/r/20240704170424.1466941-8-bigeasy@linutronix.de (cherry picked from 2b84def990d388bed4afe4f21ae383a01991046c) Signed-off-by: Kevin Becker <kevin.becker@canonical.com> Acked-by: Magali Lemes <magali.lemes@canonical.com> Acked-by: John Cabaj <john.cabaj@canonical.com>