提交 64a16caf 编写于 作者: O Oleg Nesterov 提交者: Linus Torvalds

do_wait: simplify retval/tsk_result/notask_error mess

Now that we don't pass &retval down to other helpers we can simplify
the code more.

- kill tsk_result, just use retval

- add the "notask" label right after the main loop, and
  s/got end/goto notask/ after the fastpath pid check.

  This way we don't need to initialize retval before this
  check and the code becomes a bit more clean, if this pid
  has no attached tasks we should just skip the list search.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 9e8ae01d
......@@ -1576,27 +1576,22 @@ static long do_wait(struct wait_opts *wo)
* might later match our criteria, even if we are not able to reap
* it yet.
*/
retval = wo->notask_error = -ECHILD;
wo->notask_error = -ECHILD;
if ((wo->wo_type < PIDTYPE_MAX) &&
(!wo->wo_pid || hlist_empty(&wo->wo_pid->tasks[wo->wo_type])))
goto end;
goto notask;
current->state = TASK_INTERRUPTIBLE;
read_lock(&tasklist_lock);
tsk = current;
do {
int tsk_result = do_wait_thread(wo, tsk);
if (!tsk_result)
tsk_result = ptrace_do_wait(wo, tsk);
retval = do_wait_thread(wo, tsk);
if (retval)
goto end;
if (tsk_result) {
/*
* tasklist_lock is unlocked and we have a final result.
*/
retval = tsk_result;
retval = ptrace_do_wait(wo, tsk);
if (retval)
goto end;
}
if (wo->wo_flags & __WNOTHREAD)
break;
......@@ -1605,6 +1600,7 @@ static long do_wait(struct wait_opts *wo)
} while (tsk != current);
read_unlock(&tasklist_lock);
notask:
retval = wo->notask_error;
if (!retval && !(wo->wo_flags & WNOHANG)) {
retval = -ERESTARTSYS;
......
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