Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 18 Sep 2002 15:14:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 18 Sep 2002 15:14:58 -0400 Received: from dfw-gate4.raytheon.com ([199.46.199.233]:14534 "EHLO dfw-gate4.raytheon.com") by vger.kernel.org with ESMTP id ; Wed, 18 Sep 2002 15:14:58 -0400 Subject: Re: [PATCH] recognize MAP_LOCKED in mmap() call To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, owner-linux-mm@kvack.org X-Mailer: Lotus Notes Release 5.0.8 June 18, 2001 Message-ID: From: Mark_H_Johnson@raytheon.com Date: Wed, 18 Sep 2002 14:18:05 -0500 X-MIMETrack: Serialize by Router on RTSHOU-DS01/RTS/Raytheon/US(Release 5.0.10 |March 22, 2002) at 09/18/2002 02:18:09 PM MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1312 Lines: 35 Andrew Morton wrote: >(SuS really only anticipates that mmap needs to look at prior mlocks >in force against the address range. It also says > > Process memory locking does apply to shared memory regions, > >and we don't do that either. I think we should; can't see why SuS >requires this.) Let me make sure I read what you said correctly. Does this mean that Linux 2.4 (or 2.5) kernels do not lock shared memory regions if a process uses mlockall? If not, that is *really bad* for our real time applications. We don't want to take a page fault while running some 80hz task, just because some non-real time application tried to use what little physical memory we allow for the kernel and all other applications. I asked a related question about a week ago on linux-mm and didn't get a response. Basically, I was concerned that top did not show RSS == Size when mlockall(MCL_CURRENT|MCL_FUTURE) was called. Could this explain the difference or is there something else that I'm missing here? Thanks. --Mark H Johnson - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/