From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 1 Dec 2001 03:28:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 1 Dec 2001 03:28:43 -0500 Received: from mail.spylog.com ([194.67.35.220]:52449 "HELO mail.spylog.com") by vger.kernel.org with SMTP id ; Sat, 1 Dec 2001 03:28:24 -0500 Date: Sat, 1 Dec 2001 11:31:30 +0300 From: Peter Zaitsev X-Mailer: The Bat! (v1.53d) Reply-To: Peter Zaitsev Organization: http://www.spylog.ru X-Priority: 3 (Normal) Message-ID: <61437219298.20011201113130@spylog.ru> To: theowl@freemail.c3.hu Cc: theowl@freemail.hu, linux-kernel@vger.kernel.org Subject: Re[2]: your mail on mmap() to the kernel list In-Reply-To: <3C082244.8587.80EF082@localhost> In-Reply-To: <3C082244.8587.80EF082@localhost> MIME-Version: 1.0 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 Hello theowl, Saturday, December 01, 2001, 2:20:20 AM, you wrote: Well. Thank you. I've allready found this - in recent kernels it's even regulated via proc fs. The only question is why map anonymous is rather fast (i get 1000req/sec even then mapped 300.000 of blocks), therefore with mapping a fd the perfomance drops to 20req/second at this number. Any ideas why does this happen or any patches which increases the speed exists ? tfch> in include/linux/sched.h: tfch> /* Maximum number of active map areas.. This is a random (large) number */ tfch> #define MAX_MAP_COUNT (65536) tfch> this should probably be (TASK_SIZE / PAGE_SIZE) on 32 bit architectures tfch> and something 'reasonably big' on 64 bit (too big of a value would tfch> allow for a nice DoS against the kernel). -- Best regards, Peter mailto:pz@spylog.ru