• Peter Zijlstra's avatar
    sched, exit: Deal with nested sleeps · 1029a2b5
    Peter Zijlstra authored
    do_wait() is a big wait loop, but we set TASK_RUNNING too late; we end
    up calling potential sleeps before we reset it.
    
    Not strictly a bug since we're guaranteed to exit the loop and not
    call schedule(); put in annotations to quiet might_sleep().
    
     WARNING: CPU: 0 PID: 1 at ../kernel/sched/core.c:7123 __might_sleep+0x7e/0x90()
     do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff8109a788>] do_wait+0x88/0x270
    
     Call Trace:
      [<ffffffff81694991>] dump_stack+0x4e/0x7a
      [<ffffffff8109877c>] warn_slowpath_common+0x8c/0xc0
      [<ffffffff8109886c>] warn_slowpath_fmt+0x4c/0x50
      [<ffffffff810bca6e>] __might_sleep+0x7e/0x90
      [<ffffffff811a1c15>] might_fault+0x55/0xb0
      [<ffffffff8109a3fb>] wait_consider_task+0x90b/0xc10
      [<ffffffff8109a804>] do_wait+0x104/0x270
      [<ffffffff8109b837>] SyS_wait4+0x77/0x100
      [<ffffffff8169d692>] system_call_fastpath+0x16/0x1b
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Cc: tglx@linutronix.de
    Cc: umgwanakikbuti@gmail.com
    Cc: ilya.dryomov@inktank.com
    Cc: Alex Elder <alex.elder@linaro.org>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Axel Lin <axel.lin@ingics.com>
    Cc: Daniel Borkmann <dborkman@redhat.com>
    Cc: Dave Jones <davej@redhat.com>
    Cc: Guillaume Morin <guillaume@morinfr.org>
    Cc: Ionut Alexa <ionut.m.alexa@gmail.com>
    Cc: Jason Baron <jbaron@akamai.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Michal Hocko <mhocko@suse.cz>
    Cc: Michal Schmidt <mschmidt@redhat.com>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    Cc: Rik van Riel <riel@redhat.com>
    Cc: Rusty Russell <rusty@rustcorp.com.au>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    Link: http://lkml.kernel.org/r/20140924082242.186408915@infradead.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    1029a2b5
exit.c 42 KB