From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752694Ab1AZHOQ (ORCPT ); Wed, 26 Jan 2011 02:14:16 -0500 Received: from hera.kernel.org ([140.211.167.34]:32933 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750809Ab1AZHOP (ORCPT ); Wed, 26 Jan 2011 02:14:15 -0500 Date: Wed, 26 Jan 2011 07:13:45 GMT From: tip-bot for Mathieu Desnoyers Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, mathieu.desnoyers@efficios.com, davem@davemloft.net, fweisbec@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, davem@davemloft.net, fweisbec@gmail.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <20110121203643.046218322@efficios.com> References: <20110121203643.046218322@efficios.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] tracepoints: Use __u64_aligned/U64_ALIGN() Message-ID: Git-Commit-ID: 15e3540ce2159705f18fad6147ffedf04445ad64 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Wed, 26 Jan 2011 07:13:46 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 15e3540ce2159705f18fad6147ffedf04445ad64 Gitweb: http://git.kernel.org/tip/15e3540ce2159705f18fad6147ffedf04445ad64 Author: Mathieu Desnoyers AuthorDate: Fri, 21 Jan 2011 15:36:33 -0500 Committer: Steven Rostedt CommitDate: Fri, 21 Jan 2011 22:12:13 -0500 tracepoints: Use __u64_aligned/U64_ALIGN() commit 7e066fb870fcd1025ec3ba7bbde5d541094f4ce1 added the aligned(32) type and variable attribute to the tracepoint structures to deal with gcc happily aligning statically defined structures on 32-byte multiples. Working on issues within Ftrace, we came up with __64_aligned, which deals with this issue more elegantly by forcing an 8-byte alignment to both the type declaration and variable definition. This therefore saves space, bringing down the size of struct tracepoint from 64 bytes to 38 on 64-bit architectures. Updating: - The type attribute (for iteration over the struct tracepoint array) - Added the variable attribute to the extern definition (needed to force gcc to consider this alignment for the following definition) - The definition variable attribute (to force gcc to this specific alignment for the static definitions) - The linker script (8-byte alignment can now replace the previous 32-byte alignment for the custom tracepoint section) Signed-off-by: Mathieu Desnoyers LKML-Reference: <20110121203643.046218322@efficios.com> Acked-by: David Miller CC: Frederic Weisbecker CC: Ingo Molnar Signed-off-by: Steven Rostedt --- include/asm-generic/vmlinux.lds.h | 2 +- include/linux/tracepoint.h | 12 ++++-------- 2 files changed, 5 insertions(+), 9 deletions(-) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index e4af65c..95abb5f 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -176,7 +176,7 @@ CPU_KEEP(exit.data) \ MEM_KEEP(init.data) \ MEM_KEEP(exit.data) \ - . = ALIGN(32); \ + U64_ALIGN(); \ VMLINUX_SYMBOL(__start___tracepoints) = .; \ *(__tracepoints) \ VMLINUX_SYMBOL(__stop___tracepoints) = .; \ diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index c681461..4bc50ea 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -33,12 +33,7 @@ struct tracepoint { void (*regfunc)(void); void (*unregfunc)(void); struct tracepoint_func __rcu *funcs; -} __attribute__((aligned(32))); /* - * Aligned on 32 bytes because it is - * globally visible and gcc happily - * align these on the structure size. - * Keep in sync with vmlinux.lds.h. - */ +} __u64_aligned; /* * Connect a probe to a tracepoint. @@ -146,7 +141,7 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin, * structure. Force alignment to the same alignment as the section start. */ #define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \ - extern struct tracepoint __tracepoint_##name; \ + extern struct tracepoint __u64_aligned __tracepoint_##name; \ static inline void trace_##name(proto) \ { \ JUMP_LABEL(&__tracepoint_##name.state, do_trace); \ @@ -178,7 +173,8 @@ do_trace: \ static const char __tpstrtab_##name[] \ __attribute__((section("__tracepoints_strings"))) = #name; \ struct tracepoint __tracepoint_##name \ - __attribute__((section("__tracepoints"), aligned(32))) = \ + __u64_aligned \ + __attribute__((section("__tracepoints"))) = \ { __tpstrtab_##name, 0, reg, unreg, NULL } #define DEFINE_TRACE(name) \