From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel GUILLET Date: Wed, 05 Feb 2003 17:03:26 +0000 Subject: Re: [Linux-ia64] Preempt problems Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Hello, I've just found a problem when using preemption patch with SMP on a 2.5.59 kernel. (with my version of the _raw_write_trylock() macro) It seems, that the SCSI driver have some problems (at boot time): As a result, sometimes, one of my partition (type ext3) can not be mounted. Here is the only related message in the log file : Feb 5 17:54:13 zli22 kernel: scsi: Underflow detected - retrying command. Sometimes, the partition is "half-mounted". I can only read one part of the files. If I try to mount it again or to unmount it, I've got a message saying that the device is busy. > mount /dev/sda4 umount: /home: device is busy It seems to me, that it is a deadlock. But it's not easy to identify it because, it doesn't happen every time I boot the machine (about 1/2, with my machines that have 2 cpus)) It could be a problem in the "_raw_write_trylock()", but I have made some tests, and it seems that the macro "returns" the good value. --------------- > ... because the rw_lock value is composed with : > - 1 bit for the write "flag" (the most significant bit of a _long_ value) Oh... I meant MSB of an _int_ value ! > - 31 bits for the read flags Regards --------- Joel