From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752043Ab2HaHdS (ORCPT ); Fri, 31 Aug 2012 03:33:18 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:34410 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751774Ab2HaHdQ (ORCPT ); Fri, 31 Aug 2012 03:33:16 -0400 MIME-Version: 1.0 From: Nobuhiro Iwamatsu Date: Fri, 31 Aug 2012 16:32:45 +0900 X-Google-Sender-Auth: UF5ESZ3hDO4XZXi67ogb9_VRkW0 Message-ID: Subject: Can not get output of command line on SH To: Al Viro Cc: Paul Mundt , Linux Kernel Mailing List Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Al. I can not get output of command line on SH in latest linux kernel. I bisected, I confirmed that this problem occurred by following commit. ----- commit 4a9d4b024a3102fc083c925c242d98ac27b1c5f6 Author: Al Viro Date: Sun Jun 24 09:56:45 2012 +0400 switch fput to task_work_add ... and schedule_work() for interrupt/kernel_thread callers (and yes, now it *is* OK to call from interrupt). We are guaranteed that __fput() will be done before we return to userland (or exit). Note that for fput() from a kernel thread we get an async behaviour; it's almost always OK, but sometimes you might need to have __fput() completed before you do anything else. There are two mechanisms for that - a general barrier (flush_delayed_fput()) and explicit __fput_sync(). Both should be used with care (as was the case for fput() from kernel threads all along). See comments in fs/file_table.c for details. Signed-off-by: Al Viro ----- For example ,when I input 'ls', nothing is displayed. However, it is outputted when 'Ctrl+C' is inputted. I checked other CPUs, it is only SH that this problem occurs. Paul, do you think about this? Best regards, Nobuhiro -- Nobuhiro Iwamatsu