Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764877AbYB0DJU (ORCPT ); Tue, 26 Feb 2008 22:09:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755190AbYB0DJH (ORCPT ); Tue, 26 Feb 2008 22:09:07 -0500 Received: from 136-022.dsl.labridge.com ([206.117.136.22]:2856 "EHLO mail.perches.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752538AbYB0DJG (ORCPT ); Tue, 26 Feb 2008 22:09:06 -0500 Subject: [PATCH] linux/kernel.h linux/device.h - Convert debug functions declared inline __attribute__((format (printf,x,y) to statement expression macros From: Joe Perches To: LKML Cc: Linus Torvalds , Ingo Molnar , Jeff Garzik , Greg Kroah-Hartman Content-Type: text/plain Date: Tue, 26 Feb 2008 19:08:42 -0800 Message-Id: <1204081722.19319.405.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0-2mdv2008.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3546 Lines: 117 When DEBUG is not defined, pr_debug and dev_dbg and some other local debugging functions are specified as: "inline __attribute__((format (printf, x, y)))" This is done to validate printk arguments when not debugging. Converting these functions to macros or statement expressions "do { if (0) printk(fmt, ##arg); } while (0)" or "({ if (0) printk(fmt, ##arg); 0; }) makes at least gcc 4.2.2 produce smaller objects. This has the additional benefit of allowing the optimizer to avoid calling functions like print_mac that might have been arguments to the printk. defconfig x86 current: $ size vmlinux text data bss dec hex filename 4716770 474560 618496 5809826 58a6a2 vmlinux all converted: (More patches follow) $ size vmlinux text data bss dec hex filename 4716642 474560 618496 5809698 58a622 vmlinux Even kernel/sched.o, which doesn't even use these functions, becomes smaller. It appears that merely having an indirect include of can cause bigger objects. $ size sched.inline.o sched.if0.o text data bss dec hex filename 31385 2854 328 34567 8707 sched.inline.o 31366 2854 328 34548 86f4 sched.if0.o The current preprocessed only kernel/sched.i file contains: # 612 "include/linux/device.h" static inline __attribute__((always_inline)) int __attribute__ ((format (printf, 2, 3))) dev_dbg(struct device *dev, const char *fmt, ...) { return 0; } # 628 "include/linux/device.h" static inline __attribute__((always_inline)) int __attribute__ ((format (printf, 2, 3))) dev_vdbg(struct device *dev, const char *fmt, ...) { return 0; } Removing these unused inlines from sched.i shrinks sched.o Signed-off-by: Joe Perches include/linux/kernel.h | 6 ++---- include/linux/device.h | 15 +++++---------- diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 2df44e7..cd6d02c 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -293,10 +293,8 @@ extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type, #define pr_debug(fmt, arg...) \ printk(KERN_DEBUG fmt, ##arg) #else -static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...) -{ - return 0; -} +#define pr_debug(fmt, arg...) \ + ({ if (0) printk(KERN_DEBUG fmt, ##arg); 0; }) #endif /* diff --git a/include/linux/device.h b/include/linux/device.h index 2258d89..12186e5 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -608,21 +608,16 @@ extern const char *dev_driver_string(struct device *dev); #define dev_dbg(dev, format, arg...) \ dev_printk(KERN_DEBUG , dev , format , ## arg) #else -static inline int __attribute__ ((format (printf, 2, 3))) -dev_dbg(struct device *dev, const char *fmt, ...) -{ - return 0; -} +#define dev_dbg(dev, format, arg...) \ + ({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; }) #endif #ifdef VERBOSE_DEBUG #define dev_vdbg dev_dbg #else -static inline int __attribute__ ((format (printf, 2, 3))) -dev_vdbg(struct device *dev, const char *fmt, ...) -{ - return 0; -} + +#define dev_vdbg(dev, format, arg...) \ + ({ if (0) dev_printk(KERN_DEBUG, dev, format, ##arg); 0; }) #endif /* Create alias, so I can be autoloaded. */ -- 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/