From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756632Ab1IBWyp (ORCPT ); Fri, 2 Sep 2011 18:54:45 -0400 Received: from cantor2.suse.de ([195.135.220.15]:38974 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756537Ab1IBWy2 (ORCPT ); Fri, 2 Sep 2011 18:54:28 -0400 From: Jan Kara To: Jens Axboe Cc: LKML , Jan Kara , Wu Fengguang , Andrew Morton Subject: [PATCH 2/2] mm: Add comment explaining task state setting in bdi_forker_thread() Date: Sat, 3 Sep 2011 00:54:19 +0200 Message-Id: <1315004059-9844-3-git-send-email-jack@suse.cz> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1315004059-9844-1-git-send-email-jack@suse.cz> References: <1315004059-9844-1-git-send-email-jack@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org CC: Wu Fengguang CC: Andrew Morton Signed-off-by: Jan Kara --- mm/backing-dev.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 94a047b..a87da52 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -401,6 +401,13 @@ static int bdi_forker_thread(void *ptr) } spin_lock_bh(&bdi_lock); + /* + * In the following loop we are going to check whether we have + * some work to do without any synchronization with tasks + * waking us up to do work for them. So we have to set task + * state already here so that we don't miss wakeups coming + * after we verify some condition. + */ set_current_state(TASK_INTERRUPTIBLE); list_for_each_entry(bdi, &bdi_list, bdi_list) { -- 1.7.1