From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272319AbTHOXJs (ORCPT ); Fri, 15 Aug 2003 19:09:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272322AbTHOXJs (ORCPT ); Fri, 15 Aug 2003 19:09:48 -0400 Received: from postoffice02.Princeton.EDU ([128.112.130.38]:37109 "EHLO Princeton.EDU") by vger.kernel.org with ESMTP id S272319AbTHOXJq (ORCPT ); Fri, 15 Aug 2003 19:09:46 -0400 Message-ID: <3F3D672D.1AF660B6@cs.princeton.edu> Date: Fri, 15 Aug 2003 19:05:17 -0400 From: Yaoping Ruan X-Mailer: Mozilla 4.76 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: kernel hangs up - possible sendfile() epoll() bug? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, Recently we updated a user space web server to use the sendfile() and epoll() interface, and tried to measure the performance with SpecWeb99 benchmark. As the load increases, e.g a SpecWeb99's target score of 600 connection, the kernel sometimes hangs up without any logging information, and the only way left is to push the reset button to reboot. We also made similar updates to use sendfile() and kevent() on FreeBSD and achieved a score of 1000 connections. Thus the possibility of application bug is low (also it is a user space server). Before the sendfile() and epoll() change, it was also fine but only could get a SpecWeb99 score of 500. The kernel we were using was 2.4.21 with the epoll patch applied. Since the epoll man pages mention the interface is stabilized in 2.5.66, we also tried 2.5.66 but didn't see anything better. The machine is a PIII Xeon processor-based Intel server motherboard, with 2 CPU support but only 1 is used, Maxtor Diamond IDE disk, Promise Ultra DMA 66 controller, and a single Netgear GA621 gigabit ethernet network adapter. Is this possibly caused by the newly introduced interfaces?