From 178be793485d70d871a0fd46b29e9e3e7da636ad Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 15 Oct 2007 17:00:18 +0200 Subject: [PATCH] sched: do not normalize kernel threads via SysRq-N do not normalize kernel threads via SysRq-N: the migration threads, softlockup threads, etc. might be essential for the system to function properly. So only zap user tasks. pointed out by Andi Kleen. Signed-off-by: Ingo Molnar --- kernel/sched.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index fc61b1fc67d..791dd08c692 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -365,15 +365,6 @@ static inline int cpu_of(struct rq *rq) #endif } -static inline int is_migration_thread(struct task_struct *p, struct rq *rq) -{ -#ifdef CONFIG_SMP - return p == rq->migration_thread; -#else - return 0; -#endif -} - /* * Update the per-runqueue clock, as finegrained as the platform can give * us, but without assuming monotonicity, etc.: @@ -6563,6 +6554,12 @@ void normalize_rt_tasks(void) read_lock_irq(&tasklist_lock); do_each_thread(g, p) { + /* + * Only normalize user tasks: + */ + if (!p->mm) + continue; + p->se.exec_start = 0; #ifdef CONFIG_SCHEDSTATS p->se.wait_start = 0; @@ -6584,8 +6581,7 @@ void normalize_rt_tasks(void) spin_lock_irqsave(&p->pi_lock, flags); rq = __task_rq_lock(p); - if (!is_migration_thread(p, rq)) - normalize_task(rq, p); + normalize_task(rq, p); __task_rq_unlock(rq); spin_unlock_irqrestore(&p->pi_lock, flags); -- 2.20.1