Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760487Ab2EIRW1 (ORCPT ); Wed, 9 May 2012 13:22:27 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:41389 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755283Ab2EIRW0 (ORCPT ); Wed, 9 May 2012 13:22:26 -0400 Date: Wed, 9 May 2012 19:22:20 +0200 From: Ingo Molnar To: Joe Perches Cc: Peter Zijlstra , Igor Mammedov , Jiang Liu , linux-kernel@vger.kernel.org, pjt@google.com, tglx@linutronix.de, seto.hidetoshi@jp.fujitsu.com, Andrew Morton , Linus Torvalds Subject: Re: [RFC][PATCH] printk: Add %pb to print bitmaps Message-ID: <20120509172220.GA8135@gmail.com> References: <1336566644.2527.33.camel@twins> <1336570043.2527.38.camel@twins> <20120509133607.GA26124@gmail.com> <1336571049.2527.43.camel@twins> <1336571947.2527.47.camel@twins> <20120509141528.GA3623@gmail.com> <1336577562.2527.58.camel@twins> <20120509154116.GC2653@gmail.com> <1336579592.2527.60.camel@twins> <1336581561.1905.3.camel@joe2Laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1336581561.1905.3.camel@joe2Laptop> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1710 Lines: 53 * Joe Perches wrote: > On Wed, 2012-05-09 at 18:06 +0200, Peter Zijlstra wrote: > > On Wed, 2012-05-09 at 17:41 +0200, Ingo Molnar wrote: > > > * Peter Zijlstra wrote: > > > > > > > On Wed, 2012-05-09 at 16:15 +0200, Ingo Molnar wrote: > > > > > > I guess I should use %.*pb and keep the field_width in case someone > > > > > > manages to actually make bitmap_scnlistprintf() conform to it. The > > > > > > precision is unused anyway. > > > > > > > > > > That's a cute trick, and it's intuitive as well. > > > > > > > > kernel/sched/core.c:5570:3: warning: precision used with ‘%p’ gnu_printf format [-Wformat] > > > > > > > > /me curses a bit.. anybody? > > > > > > Yeah, that's a floating point precision thing (or for strings, > > > right-align) - could you use %30pb, etc? > > > > %*pb you mean? Yeah that works, field width is allowed for %p. It does > > mean we cannot ever make bitmaps respect field width though. > > You could also fill a new struct with info > about the bitmap and pass a pointer to that. > > struct print_bitmap_info { > int foo; > int precision; > int width; > void *bitmap; > }; > ... > struct print_bitmap_info bi; > bi.foo = bar; > ... > bi.bitmap = &bitmap; > ... > printk("%pb", &bi); That defeats the whole purpose of avoiding extra complexity and preparation - just passing in the bitmap pointer is the most natural, most intuitive type to use. Thanks, Ingo -- 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/