From: Thomas Gleixner Date: Wed, 21 Sep 2011 19:57:12 +0200 Subject: [PATCH 032/353] signal: Revert ptrace preempt magic Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=644d41a2ad0eeb0b4c8f45d97302becdc9270125 Upstream commit '53da1d9456fe7f8 fix ptrace slowness' is nothing more than a bandaid around the ptrace design trainwreck. It's not a correctness issue, it's merily a cosmetic bandaid. Signed-off-by: Thomas Gleixner --- kernel/signal.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index c79b87ac1041..5f2df0301cd2 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2099,15 +2099,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) if (gstop_done && ptrace_reparented(current)) do_notify_parent_cldstop(current, false, why); - /* - * Don't want to allow preemption here, because - * sys_ptrace() needs this task to be inactive. - * - * XXX: implement read_unlock_no_resched(). - */ - preempt_disable(); read_unlock(&tasklist_lock); - preempt_enable_no_resched(); freezable_schedule(); } else { /*