From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 19 Apr 2001 09:54:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 19 Apr 2001 09:54:41 -0400 Received: from oboe.it.uc3m.es ([163.117.139.101]:38415 "EHLO oboe.it.uc3m.es") by vger.kernel.org with ESMTP id ; Thu, 19 Apr 2001 09:54:24 -0400 From: "Peter T. Breuer" Message-Id: <200104191354.f3JDs7C27006@oboe.it.uc3m.es> Subject: Re: block devices don't work without plugging in 2.4.3 In-Reply-To: <20010419152443.B22517@suse.de> from "Jens Axboe" at "Apr 19, 2001 03:24:43 pm" To: "Jens Axboe" Date: Thu, 19 Apr 2001 15:54:07 +0200 (MET DST) CC: "linux kernel" X-Anonymously-To: Reply-To: ptb@it.uc3m.es X-Mailer: ELM [version 2.4ME+ PL66 (25)] 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 OK - agreed. But while I have your attention... "Jens Axboe wrote:" > On the contrary, you are now given an exceptional opportunity to clean > up your code and get rid of blk_queue_pluggable and your noop plugging > function. In summary: blk_queue_pluggable can be removed for all driver codes aimed at all 2.4.* kernels, because the intended effect can be obtained through merge_reqeusts function controls. My unease derives, I think, from the fact that I have occasionally used plugging for other purposes. Namely for throttling the device. These uses have always been experimental and uniformly unsuccessful, because throttling that way backs up the VFS with dirty buffers and provokes precisely the deadlock against VFS that I was trying to avoid. So .. ... how can I tell when VFS is nearly full? In those circumstances I want to sync every _other_ device, thus giving me enough buffers at least to flush something to the net with, thus freeing a request of mine, plus its buffers. Peter