Return-Path: Received: from fieldses.org ([174.143.236.118]:56507 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751649Ab0GFRTR (ORCPT ); Tue, 6 Jul 2010 13:19:17 -0400 Date: Tue, 6 Jul 2010 13:19:08 -0400 From: "J. Bruce Fields" To: Artem Bityutskiy , Thomas Gleixner Cc: Neil Brown , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, Venki Pallipadi Subject: [PATCH] timers.c: document meaning of deferrable timer Message-ID: <20100706171908.GL7387@fieldses.org> References: <1277996756-8415-1-git-send-email-dedekind1@gmail.com> Content-Type: text/plain; charset=us-ascii In-Reply-To: <1277996756-8415-1-git-send-email-dedekind1@gmail.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 From: J. Bruce Fields Steal some text from 6e453a67510 "Add support for deferrable timers". A reader shouldn't have to dig through the git logs for the basic description of a deferrable timer. Signed-off-by: J. Bruce Fields --- kernel/timer.c | 9 +++++++-- 1 files changed, 7 insertions(+), 2 deletions(-) diff --git a/kernel/timer.c b/kernel/timer.c index ee305c8..947bcf6 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -90,8 +90,13 @@ static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases; /* * Note that all tvec_bases are 2 byte aligned and lower bit of - * base in timer_list is guaranteed to be zero. Use the LSB for - * the new flag to indicate whether the timer is deferrable + * base in timer_list is guaranteed to be zero. Use the LSB to + * indicate whether the timer is deferrable. + * + * A deferrable timer will work normally when the system is busy, but + * will not cause a CPU to come out of idle just to service it; instead, + * the timer will be serviced when the CPU eventually wakes up with a + * subsequent non-deferrable timer. */ #define TBASE_DEFERRABLE_FLAG (0x1) -- 1.7.0.4