From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758670AbZGIADP (ORCPT ); Wed, 8 Jul 2009 20:03:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756713AbZGIADC (ORCPT ); Wed, 8 Jul 2009 20:03:02 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:52399 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756513AbZGIADA (ORCPT ); Wed, 8 Jul 2009 20:03:00 -0400 Date: Wed, 8 Jul 2009 17:01:14 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Anton Vorontsov cc: Andrew Morton , a.p.zijlstra@chello.nl, oleg@redhat.com, mingo@elte.hu, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH] netpoll: Fix carrier detection for drivers that are using phylib In-Reply-To: <20090708222003.GA12318@oksana.dev.rtsoft.ru> Message-ID: References: <20090707235812.GA12824@oksana.dev.rtsoft.ru> <20090708005000.GA12380@redhat.com> <1247034263.9777.24.camel@twins> <20090708141024.f8b581c5.akpm@linux-foundation.org> <20090708213331.GA9346@oksana.dev.rtsoft.ru> <20090708144744.5555b88d.akpm@linux-foundation.org> <20090708222003.GA12318@oksana.dev.rtsoft.ru> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 9 Jul 2009, Anton Vorontsov wrote: > > The netpoll code is using msleep() just a few lines below cond_resched(), > so we won't make things worse. ;-) Yeah. That function is definitely sleeping. It does things like kmalloc(GFP_KERNEL), rtnl_lock() and synchronize_rcu() etc too, so an added msleep() is the least of our problems. Afaik, it's called from a bog-standard "module_init()", which happens late enough that everything works. In fact, I wonder if we should set SYSTEM_RUNNING much earlier - _before_ doing the whole "do_initcalls()". By then we've set up all the core stuff and enabled interrupts, so we really _are_ running. We just don't necessarily have drivers, filesystems etc loaded yet. But anything that happens late enough to be an initcall should be largely considered to be during "normal code". (The "early_initcall" cases are special - those really do happen pretty early). So ACK on Anton's patch, but I wonder if we _also_ should do the following? Looking at the people looking at SYSTEM_RUNNING, I do note some odd cases. Why the heck does kernel/perf_counter.c do it, for example? Linus --- init/main.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/init/main.c b/init/main.c index 2c5ade7..f10d9cd 100644 --- a/init/main.c +++ b/init/main.c @@ -788,6 +788,7 @@ static void __init do_initcalls(void) { initcall_t *call; + system_state = SYSTEM_RUNNING; for (call = __early_initcall_end; call < __initcall_end; call++) do_one_initcall(*call); @@ -839,7 +840,6 @@ static noinline int init_post(void) free_initmem(); unlock_kernel(); mark_rodata_ro(); - system_state = SYSTEM_RUNNING; numa_default_policy(); if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)