* Mike Galbraith | 2016-01-18 10:08:23 [+0100]: >--- a/arch/x86/entry/common.c >+++ b/arch/x86/entry/common.c >@@ -220,14 +220,14 @@ long syscall_trace_enter(struct pt_regs > > #define EXIT_TO_USERMODE_LOOP_FLAGS \ > (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_UPROBE | \ >- _TIF_NEED_RESCHED | _TIF_USER_RETURN_NOTIFY) >+ _TIF_NEED_RESCHED_MASK | _TIF_USER_RETURN_NOTIFY) > If I read this right, the loop where this define is used _TIF_ALLWORK_MASK in v4.1 of which _TIF_NEED_RESCHED_MASK was part of. Adding this will reassmeble the old behaviour. … >--- a/kernel/sched/core.c >+++ b/kernel/sched/core.c >@@ -3542,6 +3542,15 @@ asmlinkage __visible void __sched notrac > if (likely(!preemptible())) > return; > >+#ifdef CONFIG_PREEMPT_LAZY >+ /* >+ * Check for lazy preemption >+ */ >+ if (current_thread_info()->preempt_lazy_count && >+ !test_thread_flag(TIF_NEED_RESCHED)) >+ return; >+#endif >+ And this is a new piece. So you forbid that tasks leave the CPU if lazy_count > 0. Let me look closed why this is happening and if this is v4.1 … v4.4 or not. > preempt_schedule_common(); > } > NOKPROBE_SYMBOL(preempt_schedule); Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
