From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753438Ab0IWD5L (ORCPT ); Wed, 22 Sep 2010 23:57:11 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:51959 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752857Ab0IWD4K (ORCPT ); Wed, 22 Sep 2010 23:56:10 -0400 X-Authority-Analysis: v=1.1 cv=Yii9LXZpONf3Dl4H+sCjsa4WyoNNo7yi1hAau1xJxWE= c=1 sm=0 a=TKZLANPSWycA:10 a=bbbx4UPp9XUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=20KFwNOVAAAA:8 a=meVymXHHAAAA:8 a=7QaA4eaBAAAA:8 a=akZKmJtmgmBz-tsVswkA:9 a=6my5UTmbp83ARSNSDf8A:7 a=38hr-wPIAe0DVYgGx0h8-PdlL9UA:4 a=hNGwCf7pllMA:10 a=jEp0ucaQiEUA:10 a=jeBq3FmKZ4MA:10 a=I0JLvpeDBZNMyrX5:21 a=LJCObVS7as0PApUl:21 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Message-Id: <20100923035609.120909876@goodmis.org> User-Agent: quilt/0.48-1 Date: Wed, 22 Sep 2010 23:49:17 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Frederic Weisbecker , Mathieu Desnoyers , Andi Kleen , Jason Baron , David Miller Subject: [PATCH 07/11] jump label: Convert dynamic debug to use jump labels References: <20100923034910.867858597@goodmis.org> Content-Disposition: inline; filename=0007-jump-label-Convert-dynamic-debug-to-use-jump-labels.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason Baron Convert the 'dynamic debug' infrastructure to use jump labels. Signed-off-by: Jason Baron LKML-Reference: Signed-off-by: Steven Rostedt --- include/linux/dynamic_debug.h | 39 +++++++++++++----------- lib/dynamic_debug.c | 42 ++------------------------- scripts/Makefile.lib | 11 +------ scripts/basic/Makefile | 2 +- scripts/basic/hash.c | 64 ----------------------------------------- 5 files changed, 26 insertions(+), 132 deletions(-) delete mode 100644 scripts/basic/hash.c diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 52c0da4..bef3cda 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -1,6 +1,8 @@ #ifndef _DYNAMIC_DEBUG_H #define _DYNAMIC_DEBUG_H +#include + /* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They * use independent hash functions, to reduce the chance of false positives. @@ -22,8 +24,6 @@ struct _ddebug { const char *function; const char *filename; const char *format; - char primary_hash; - char secondary_hash; unsigned int lineno:24; /* * The flags field controls the behaviour at the callsite. @@ -33,6 +33,7 @@ struct _ddebug { #define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */ #define _DPRINTK_FLAGS_DEFAULT 0 unsigned int flags:8; + char enabled; } __attribute__((aligned(8))); @@ -42,33 +43,35 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n, #if defined(CONFIG_DYNAMIC_DEBUG) extern int ddebug_remove_module(const char *mod_name); -#define __dynamic_dbg_enabled(dd) ({ \ - int __ret = 0; \ - if (unlikely((dynamic_debug_enabled & (1LL << DEBUG_HASH)) && \ - (dynamic_debug_enabled2 & (1LL << DEBUG_HASH2)))) \ - if (unlikely(dd.flags)) \ - __ret = 1; \ - __ret; }) - #define dynamic_pr_debug(fmt, ...) do { \ + __label__ do_printk; \ + __label__ out; \ static struct _ddebug descriptor \ __used \ __attribute__((section("__verbose"), aligned(8))) = \ - { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ - DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ - if (__dynamic_dbg_enabled(descriptor)) \ - printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ + { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \ + _DPRINTK_FLAGS_DEFAULT }; \ + JUMP_LABEL(&descriptor.enabled, do_printk); \ + goto out; \ +do_printk: \ + printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \ +out: ; \ } while (0) #define dynamic_dev_dbg(dev, fmt, ...) do { \ + __label__ do_printk; \ + __label__ out; \ static struct _ddebug descriptor \ __used \ __attribute__((section("__verbose"), aligned(8))) = \ - { KBUILD_MODNAME, __func__, __FILE__, fmt, DEBUG_HASH, \ - DEBUG_HASH2, __LINE__, _DPRINTK_FLAGS_DEFAULT }; \ - if (__dynamic_dbg_enabled(descriptor)) \ - dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \ + { KBUILD_MODNAME, __func__, __FILE__, fmt, __LINE__, \ + _DPRINTK_FLAGS_DEFAULT }; \ + JUMP_LABEL(&descriptor.enabled, do_printk); \ + goto out; \ +do_printk: \ + dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); \ +out: ; \ } while (0) #else diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 02afc25..e925c7b 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -26,19 +26,11 @@ #include #include #include +#include extern struct _ddebug __start___verbose[]; extern struct _ddebug __stop___verbose[]; -/* dynamic_debug_enabled, and dynamic_debug_enabled2 are bitmasks in which - * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They - * use independent hash functions, to reduce the chance of false positives. - */ -long long dynamic_debug_enabled; -EXPORT_SYMBOL_GPL(dynamic_debug_enabled); -long long dynamic_debug_enabled2; -EXPORT_SYMBOL_GPL(dynamic_debug_enabled2); - struct ddebug_table { struct list_head link; char *mod_name; @@ -88,26 +80,6 @@ static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, } /* - * must be called with ddebug_lock held - */ - -static int disabled_hash(char hash, bool first_table) -{ - struct ddebug_table *dt; - char table_hash_value; - - list_for_each_entry(dt, &ddebug_tables, link) { - if (first_table) - table_hash_value = dt->ddebugs->primary_hash; - else - table_hash_value = dt->ddebugs->secondary_hash; - if (dt->num_enabled && (hash == table_hash_value)) - return 0; - } - return 1; -} - -/* * Search the tables for _ddebug's which match the given * `query' and apply the `flags' and `mask' to them. Tells * the user which ddebug's were changed, or whether none @@ -170,17 +142,9 @@ static void ddebug_change(const struct ddebug_query *query, dt->num_enabled++; dp->flags = newflags; if (newflags) { - dynamic_debug_enabled |= - (1LL << dp->primary_hash); - dynamic_debug_enabled2 |= - (1LL << dp->secondary_hash); + enable_jump_label(&dp->enabled); } else { - if (disabled_hash(dp->primary_hash, true)) - dynamic_debug_enabled &= - ~(1LL << dp->primary_hash); - if (disabled_hash(dp->secondary_hash, false)) - dynamic_debug_enabled2 &= - ~(1LL << dp->secondary_hash); + disable_jump_label(&dp->enabled); } if (verbose) printk(KERN_INFO diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 54fd1b7..7bfcf1a 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -101,14 +101,6 @@ basename_flags = -D"KBUILD_BASENAME=KBUILD_STR($(call name-fix,$(basetarget)))" modname_flags = $(if $(filter 1,$(words $(modname))),\ -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))") -#hash values -ifdef CONFIG_DYNAMIC_DEBUG -debug_flags = -D"DEBUG_HASH=$(shell ./scripts/basic/hash djb2 $(@D)$(modname))"\ - -D"DEBUG_HASH2=$(shell ./scripts/basic/hash r5 $(@D)$(modname))" -else -debug_flags = -endif - orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \ $(ccflags-y) $(CFLAGS_$(basetarget).o) _c_flags = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags)) @@ -152,8 +144,7 @@ endif c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ $(__c_flags) $(modkern_cflags) \ - -D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags) \ - $(debug_flags) + -D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags) a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ $(__a_flags) $(modkern_aflags) diff --git a/scripts/basic/Makefile b/scripts/basic/Makefile index 0955995..4c324a1 100644 --- a/scripts/basic/Makefile +++ b/scripts/basic/Makefile @@ -9,7 +9,7 @@ # fixdep: Used to generate dependency information during build process # docproc: Used in Documentation/DocBook -hostprogs-y := fixdep docproc hash +hostprogs-y := fixdep docproc always := $(hostprogs-y) # fixdep is needed to compile other host programs diff --git a/scripts/basic/hash.c b/scripts/basic/hash.c deleted file mode 100644 index 2ef5d3f..0000000 --- a/scripts/basic/hash.c +++ /dev/null @@ -1,64 +0,0 @@ -/* - * Copyright (C) 2008 Red Hat, Inc., Jason Baron - * - */ - -#include -#include -#include - -#define DYNAMIC_DEBUG_HASH_BITS 6 - -static const char *program; - -static void usage(void) -{ - printf("Usage: %s \n", program); - exit(1); -} - -/* djb2 hashing algorithm by Dan Bernstein. From: - * http://www.cse.yorku.ca/~oz/hash.html - */ - -static unsigned int djb2_hash(char *str) -{ - unsigned long hash = 5381; - int c; - - c = *str; - while (c) { - hash = ((hash << 5) + hash) + c; - c = *++str; - } - return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); -} - -static unsigned int r5_hash(char *str) -{ - unsigned long hash = 0; - int c; - - c = *str; - while (c) { - hash = (hash + (c << 4) + (c >> 4)) * 11; - c = *++str; - } - return (unsigned int)(hash & ((1 << DYNAMIC_DEBUG_HASH_BITS) - 1)); -} - -int main(int argc, char *argv[]) -{ - program = argv[0]; - - if (argc != 3) - usage(); - if (!strcmp(argv[1], "djb2")) - printf("%d\n", djb2_hash(argv[2])); - else if (!strcmp(argv[1], "r5")) - printf("%d\n", r5_hash(argv[2])); - else - usage(); - exit(0); -} - -- 1.7.1