From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752564AbcAWISJ (ORCPT ); Sat, 23 Jan 2016 03:18:09 -0500 Received: from mail-pa0-f67.google.com ([209.85.220.67]:36357 "EHLO mail-pa0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752054AbcAWIRU (ORCPT ); Sat, 23 Jan 2016 03:17:20 -0500 From: Sergey Senozhatsky To: Andrew Morton Cc: Petr Mladek , Jan Kara , Tejun Heo , Kyle McMartin , Dave Jones , Calvin Owens , linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky Subject: [RFC][PATCH v3 2/4] printk: do not console_cont_flush() on every jump to again Date: Sat, 23 Jan 2016 17:15:11 +0900 Message-Id: <1453536913-9545-3-git-send-email-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1453536913-9545-1-git-send-email-sergey.senozhatsky@gmail.com> References: <1453536913-9545-1-git-send-email-sergey.senozhatsky@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Every jump to `again' label will call console_cont_flush(), which is not really something big -- it just adds one extra raw_spin_lock_irqsave/raw_spin_unlock_irqrestore. However, to keep the previous behaviour we can call console_cont_flush() only when `retry' is false -- which happens once, all jumps to `again' label have `retry' set to true. Signed-off-by: Sergey Senozhatsky --- kernel/printk/printk.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index c39232a..dc722fc 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2213,7 +2213,7 @@ void console_unlock(void) static u64 seen_seq; unsigned long flags; bool wake_klogd = false; - bool do_cond_resched, retry; + bool do_cond_resched, retry = false; if (console_suspended) { up_console_sem(); @@ -2246,7 +2246,8 @@ again: } /* flush buffered message fragment immediately to console */ - console_cont_flush(text, sizeof(text)); + if (!retry) + console_cont_flush(text, sizeof(text)); for (;;) { struct printk_log *msg; -- 2.7.0