Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751606AbWHKGYN (ORCPT ); Fri, 11 Aug 2006 02:24:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751614AbWHKGYN (ORCPT ); Fri, 11 Aug 2006 02:24:13 -0400 Received: from smtp.osdl.org ([65.172.181.4]:1490 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751601AbWHKGYM (ORCPT ); Fri, 11 Aug 2006 02:24:12 -0400 Date: Thu, 10 Aug 2006 23:23:40 -0700 From: Andrew Morton To: Evgeniy Polyakov Cc: lkml , David Miller , Ulrich Drepper , netdev , Zach Brown Subject: Re: [take6 1/3] kevent: Core files. Message-Id: <20060810232340.ab326d3f.akpm@osdl.org> In-Reply-To: <20060811061535.GA11230@2ka.mipt.ru> References: <11551105592821@2ka.mipt.ru> <11551105602734@2ka.mipt.ru> <20060809152127.481fb346.akpm@osdl.org> <20060810061433.GA4689@2ka.mipt.ru> <20060810001844.ff5e7429.akpm@osdl.org> <20060810075047.GB24370@2ka.mipt.ru> <20060810010254.3b52682f.akpm@osdl.org> <20060810082235.GA21025@2ka.mipt.ru> <20060810175639.b64faaa9.akpm@osdl.org> <20060811061535.GA11230@2ka.mipt.ru> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) 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 Content-Length: 1387 Lines: 29 On Fri, 11 Aug 2006 10:15:35 +0400 Evgeniy Polyakov wrote: > On Thu, Aug 10, 2006 at 05:56:39PM -0700, Andrew Morton (akpm@osdl.org) wrote: > > > Per kevent fd. > > > I have some ideas about better mmap ring implementation, which would > > > dinamically grow it's buffer when events are added and reuse the same > > > place for next events, but there are some nitpics unresolved yet. > > > Let's not see there in next releases (no merge of course), until better > > > solution is ready. I will change that area when other things are ready. > > > > This is not a problem with the mmap interface per-se. If the proposed > > event code permits each user to pin 160MB of kernel memory then that would > > be a serious problem. > > The main disadvantage is that all memory is allocated on the start even > if it will not be used later. I think dynamic grow is appropriate > solution, since user will have that memory used anyway, since kevents > are allocated, just part of them will be allocated from possibly > mmaped memory. But the worst-case remains the same, doesn't it? 160MB of pinned kernel memory per user? - 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/