From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin LaHaise Subject: Re: [PATCH] add support for vectored and async I/O to all simple filesystems Date: Wed, 2 Nov 2005 11:45:02 -0500 Message-ID: <20051102164502.GB32755@kvack.org> References: <20051101023656.GA23724@lst.de> <20051101192000.GB29542@mail.shareable.org> <20051101205745.GB27231@kvack.org> <20051102110630.GB30550@mail.shareable.org> <20051102162107.GA32755@kvack.org> <20051102162904.GK23749@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jamie Lokier , Christoph Hellwig , akpm@osdl.org, linux-fsdevel@vger.kernel.org Return-path: Received: from kanga.kvack.org ([66.96.29.28]:7103 "EHLO kanga.kvack.org") by vger.kernel.org with ESMTP id S965112AbVKBQrP (ORCPT ); Wed, 2 Nov 2005 11:47:15 -0500 To: Matthew Wilcox Content-Disposition: inline In-Reply-To: <20051102162904.GK23749@parisc-linux.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, Nov 02, 2005 at 09:29:04AM -0700, Matthew Wilcox wrote: > To be fair, the aio system calls were never _guaranteed_ to not block, > were they? ISTR there were various corner cases that would still get > your task blocking while doing an aio submission. They're suppose to not block except for memory allocation, that is the definition of how the aio api is supposed to work. The patches to fix that always seem to get met with a "woe! complexity!" response. I'm of the opinion now that the only way to get the aio api to a usable state of implementation is to use threads so that the impact on the rest of the kernel isn't there for anything other than fast paths. -ben -- "Time is what keeps everything from happening all at once." -- John Wheeler