Return-Path: Subject: [PATCH] Bluetooth node manager causes up to ~3.25s delay in freezing tasks. From: Nigel Cunningham To: linux-bluetooth@vger.kernel.org, marcel@holtmann.org, linux-pm , LKML Content-Type: text/plain Date: Tue, 09 Dec 2008 18:55:11 +1100 Message-Id: <1228809311.6681.12.camel@nigel-laptop> Mime-Version: 1.0 List-ID: Hi all. The bluetooth nodemanager function "nodemgr_host_thread" contains a loop that calls try_to_freeze near the top of the loop, but then delays for up to 3.25 seconds (plus time to do work) before getting back to the top of the loop. When starting a cycle post-boot, this doesn't seem to bite, but it is causing a noticeable delay at boot time, when freezing processes prior to starting to read the image. The following patch adds invocation of try_to_freeze to the subloops that are used in the body of this function. With these additions, the time to freeze when starting to resume at boot time is virtually zero. I'm no expert on bluetooth, and so don't know that we shouldn't check the return value and jump back to the top of the loop or such like after being frozen, but I submit it for your consideration. Signed-off-by: Nigel Cunningham nodemgr.c | 2 ++ 1 file changed, 2 insertions(+) diff -ruNp 710-nodemanager-freezing.patch-old/drivers/ieee1394/nodemgr.c 710-nodemanager-freezing.patch-new/drivers/ieee1394/nodemgr.c --- 710-nodemanager-freezing.patch-old/drivers/ieee1394/nodemgr.c 2008-12-06 08:42:08.000000000 +1100 +++ 710-nodemanager-freezing.patch-new/drivers/ieee1394/nodemgr.c 2008-12-09 18:49:26.000000000 +1100 @@ -1685,6 +1685,7 @@ static int nodemgr_host_thread(void *dat g = get_hpsb_generation(host); for (i = 0; i < 4 ; i++) { msleep_interruptible(63); + try_to_freeze(); if (kthread_should_stop()) goto exit; @@ -1725,6 +1726,7 @@ static int nodemgr_host_thread(void *dat /* Sleep 3 seconds */ for (i = 3000/200; i; i--) { msleep_interruptible(200); + try_to_freeze(); if (kthread_should_stop()) goto exit;