From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262141AbULCKLG (ORCPT ); Fri, 3 Dec 2004 05:11:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262139AbULCKLG (ORCPT ); Fri, 3 Dec 2004 05:11:06 -0500 Received: from static64-74.dsl-blr.eth.net ([61.11.64.74]:58894 "EHLO globaledgesoft.com") by vger.kernel.org with ESMTP id S262141AbULCKLD (ORCPT ); Fri, 3 Dec 2004 05:11:03 -0500 Message-ID: <41B03BB2.90802@globaledgesoft.com> Date: Fri, 03 Dec 2004 15:40:58 +0530 From: Kiran Kumar Gaitonde User-Agent: Mozilla Thunderbird 0.8 (X11/20040913) X-Accept-Language: en-us, en MIME-Version: 1.0 To: linux-kernel Subject: Kernel Thread in Device Driver Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-Sender: kiran.gaitonde@globaledgesoft.com X-MDRemoteIP: 172.16.6.155 X-Return-Path: kiran.gaitonde@globaledgesoft.com X-MDaemon-Deliver-To: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi all. I am working on a device driver with the device interrupts are actaully serviced in a kernel thread and not in the interrupt handler registered with the kernel. The interrupt handler justs wakes up the kthread when a interrupt occurs. This is done as we need to use semaphores while performing IO to sync the read and writes. Now I have come across a situation where the kthread is consuming 70% of CPU time as it is in a loop to service the interrupts happening very very fast, and it is rearly saying schedule(). The performance of the application which uses this device to communicate, is not good as it is not getting CPU at the right time. Can anybody tell me what may be the problem. Also any suggestions to overcome this issue? Thanks in Advance, Regards, Kiran Gaitonde.