Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754417AbZGBGk1 (ORCPT ); Thu, 2 Jul 2009 02:40:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752421AbZGBGkS (ORCPT ); Thu, 2 Jul 2009 02:40:18 -0400 Received: from hera.kernel.org ([140.211.167.34]:33822 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752342AbZGBGkR (ORCPT ); Thu, 2 Jul 2009 02:40:17 -0400 Message-ID: <4A4C5638.20706@kernel.org> Date: Wed, 01 Jul 2009 23:39:52 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Ingo Molnar CC: Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , Linus Torvalds , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH, v2] x86: Fix printk call in print_local_apic() References: <4A4C3410.8080704@kernel.org> <4A4C43BC.90506@kernel.org> <20090702061254.GA23277@elte.hu> <20090702062847.GB23277@elte.hu> In-Reply-To: <20090702062847.GB23277@elte.hu> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4015 Lines: 123 Ingo Molnar wrote: > * Ingo Molnar wrote: > >>> - printk(KERN_DEBUG "0123456789abcdef0123456789abcdef\n" KERN_DEBUG); >>> + printk(KERN_DEBUG "0123456789abcdef0123456789abcdef\n"); >>> for (i = 0; i < 8; i++) { >>> + char bin[33]; >>> v = apic_read(base + i*0x10); >>> + >>> + /* Do we really want to print out LSB first? */ >> We definitely want MSB first - i'll flip around the order. > > in fact i dont remember ever having relied on the bitfield nature of > that printout. Since this is uncommon debug code, printing the plain > hexa value is more than enough. > > In fact we can compact it down to a single line: > > 0123456701234567012345670123456701234567012345670123456701234567 > > instead of 4 lines of bitfields. > > So i've done the patch below that looks quite a bit simpler. Mind > testing it, does it fix all the printout artifacts you've seen? > > Ingo > > ------------------> >>From ef611b322dc9a917c71f28f9498dfff0d3949779 Mon Sep 17 00:00:00 2001 > From: Ingo Molnar > Date: Thu, 2 Jul 2009 08:26:20 +0200 > Subject: [PATCH] x86: Fix printk call in print_local_apic() > > Instead of this: > > [ 75.690022] <7>printing local APIC contents on CPU#0/0: > [ 75.704406] ... APIC ID: 00000000 (0) > [ 75.707905] ... APIC VERSION: 00060015 > [ 75.722551] ... APIC TASKPRI: 00000000 (00) > [ 75.725473] ... APIC PROCPRI: 00000000 > [ 75.728592] ... APIC LDR: 00000001 > [ 75.742137] ... APIC SPIV: 000001ff > [ 75.744101] ... APIC ISR field: > [ 75.746648] 0123456789abcdef0123456789abcdef > [ 75.746649] <7>00000000000000000000000000000000 > > Improve the code to be saner and simpler and just print out > the bitfield in a single line using hexa values - not as a > (rather pointless) binary bitfield. > > Partially reused Linus's initial fix for this. > > Reported-and-Tested-by: Yinghai Lu > Signed-off-by: Yinghai Lu > Cc: Linus Torvalds > Cc: Andrew Morton > LKML-Reference: <4A4C43BC.90506@kernel.org> > Signed-off-by: Ingo Molnar > --- > arch/x86/kernel/apic/io_apic.c | 25 ++++++++++--------------- > 1 files changed, 10 insertions(+), 15 deletions(-) > > diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c > index 4d0216f..e32e453 100644 > --- a/arch/x86/kernel/apic/io_apic.c > +++ b/arch/x86/kernel/apic/io_apic.c > @@ -1716,25 +1716,19 @@ __apicdebuginit(void) print_IO_APIC(void) > return; > } > > -__apicdebuginit(void) print_APIC_bitfield(int base) > +__apicdebuginit(void) print_APIC_(int base) ? > { > - unsigned int v; > int i, j; > > - if (apic_verbosity == APIC_QUIET) > + if (apic_verbosity != APIC_QUIET) is this one reversed? > return; > > - printk(KERN_DEBUG "0123456789abcdef0123456789abcdef\n" KERN_DEBUG); > - for (i = 0; i < 8; i++) { > - v = apic_read(base + i*0x10); > - for (j = 0; j < 32; j++) { > - if (v & (1< - printk("1"); > - else > - printk("0"); > - } > - printk("\n"); > - } > + printk(KERN_DEBUG); > + > + for (i = 0; i < 8; i++) > + printk(KERN_CONT "%08x", i, apic_read(base + i*0x10)); > + > + printk(KERN_CONT "\n"); > } > > __apicdebuginit(void) print_local_APIC(void *dummy) > @@ -1745,7 +1739,8 @@ __apicdebuginit(void) print_local_APIC(void *dummy) > if (apic_verbosity == APIC_QUIET) > return; > > - printk("\n" KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n", > + printk(KERN_DEBUG "\n"); > + printk(KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n", > smp_processor_id(), hard_smp_processor_id()); > v = apic_read(APIC_ID); > printk(KERN_INFO "... APIC ID: %08x (%01x)\n", v, read_apic_id()); -- 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/