From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3B803FEE.7079F34C@acm.org> Date: Sun, 19 Aug 2001 15:38:38 -0700 From: Ira Weiny MIME-Version: 1.0 To: Linux1394dev , linuxppc-dev Subject: Task Queue Imediate Bottom Halfs question. Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: This is going to seem like a real stupid question but I just got burned because I did not know the answer and I would like to know. In the 1394 stack (OHCI) the IRQ handler schedules "bottom half tasklets (task queues in the old stack)". They are scheduled to be "imediate" bottom half's. I thought (wrongly) that a bottom half executed out of IRQ time with interrupts __enabled__. As a result I put in a Async Rec handler which used printk (60ms worth to be exact). Needless to say this greatly disturbed our ISO transfers which did not get processed. So, my question is, why use a bottom half here? Or really what is the difference between scheduling a task queue (tasklet) imediate vs just running the code in the IRQ handler? Thanks, Ira Weiny iweiny@acm.org ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/