From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 17 Apr 2001 12:41:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 17 Apr 2001 12:41:12 -0400 Received: from arpa.it.uc3m.es ([163.117.139.120]:51984 "EHLO arpa.it.uc3m.es") by vger.kernel.org with ESMTP id ; Tue, 17 Apr 2001 12:41:03 -0400 From: "Peter T. Breuer" Message-Id: <200104171640.f3HGeRb32326@oboe.it.uc3m.es> Subject: block devices don't work without plugging in 2.4.3 To: "linux kernel" Date: Tue, 17 Apr 2001 18:40:27 +0200 (MET DST) 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 Well, anyway, as far as I can tell, the following has been lost from __make_request() in ll_rw_blk.c since the 2.4.0 days: out: - if (!q->plugged) - (q->request_fn)(q); if (freereq) The result appears to be that if a block device has called blk_queue_pluggable() to register a no-op plug_fn, then q->plugged will never be set (it's the duty of the plug_fn), and the devices registered request function wil never be called. This behaviour is distinct from 2.4.0, where registering a no-op made things work fine. Is the policy now supposed to be that we do some more work in the "no-op"? What am I supposed to do if I don't want plugging(1)(2)? (1) goes away and looks .... (2) actually, I do want plugging, but I like to keep the no-plug option around so that I can benchmark the difference and also provide a very conservative option setting. Peter