From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Hogan Subject: [PATCH v2 04/44] trace/ring_buffer: handle 64bit aligned structs Date: Wed, 5 Dec 2012 16:08:22 +0000 Message-ID: <1354723742-6195-5-git-send-email-james.hogan@imgtec.com> References: <1354723742-6195-1-git-send-email-james.hogan@imgtec.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1354723742-6195-1-git-send-email-james.hogan@imgtec.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Arnd Bergmann , James Hogan , Steven Rostedt , Frederic Weisbecker , Ingo Molnar List-Id: linux-arch.vger.kernel.org Some 32 bit architectures have 64 bit struct alignment (for example Meta which has 64 bit read/write instructions). These require 8 byte alignment of event data too, so use CONFIG_HAVE_64BIT_ALIGNED_STRUCT instead of CONFIG_64BIT to decide alignment, and align buffer_data_page::data accordingly. Signed-off-by: James Hogan Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Ingo Molnar --- kernel/trace/ring_buffer.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index b979426..c4dc029 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -177,7 +177,8 @@ void tracing_off_permanent(void) #define RB_MAX_SMALL_DATA (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX) #define RB_EVNT_MIN_SIZE 8U /* two 32bit words */ -#if !defined(CONFIG_64BIT) || defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) +#if !defined(CONFIG_HAVE_64BIT_ALIGNED_STRUCT) || \ + defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) # define RB_FORCE_8BYTE_ALIGNMENT 0 # define RB_ARCH_ALIGNMENT RB_ALIGNMENT #else @@ -185,6 +186,8 @@ void tracing_off_permanent(void) # define RB_ARCH_ALIGNMENT 8U #endif +#define RB_ALIGN_DATA __aligned(RB_ARCH_ALIGNMENT) + /* define RINGBUF_TYPE_DATA for 'case RINGBUF_TYPE_DATA:' */ #define RINGBUF_TYPE_DATA 0 ... RINGBUF_TYPE_DATA_TYPE_LEN_MAX @@ -333,7 +336,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data); struct buffer_data_page { u64 time_stamp; /* page time stamp */ local_t commit; /* write committed index */ - unsigned char data[]; /* data of buffer page */ + unsigned char data[] RB_ALIGN_DATA; /* data of buffer page */ }; /* -- 1.7.7.6 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from multi.imgtec.com ([194.200.65.239]:51616 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752530Ab2LEQJT (ORCPT ); Wed, 5 Dec 2012 11:09:19 -0500 From: James Hogan Subject: [PATCH v2 04/44] trace/ring_buffer: handle 64bit aligned structs Date: Wed, 5 Dec 2012 16:08:22 +0000 Message-ID: <1354723742-6195-5-git-send-email-james.hogan@imgtec.com> In-Reply-To: <1354723742-6195-1-git-send-email-james.hogan@imgtec.com> References: <1354723742-6195-1-git-send-email-james.hogan@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Arnd Bergmann , James Hogan , Steven Rostedt , Frederic Weisbecker , Ingo Molnar Message-ID: <20121205160822.EFUdWkT24wODcjOzIWqGT_mc227S3J94LYriXNtTW8g@z> Some 32 bit architectures have 64 bit struct alignment (for example Meta which has 64 bit read/write instructions). These require 8 byte alignment of event data too, so use CONFIG_HAVE_64BIT_ALIGNED_STRUCT instead of CONFIG_64BIT to decide alignment, and align buffer_data_page::data accordingly. Signed-off-by: James Hogan Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Ingo Molnar --- kernel/trace/ring_buffer.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index b979426..c4dc029 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -177,7 +177,8 @@ void tracing_off_permanent(void) #define RB_MAX_SMALL_DATA (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX) #define RB_EVNT_MIN_SIZE 8U /* two 32bit words */ -#if !defined(CONFIG_64BIT) || defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) +#if !defined(CONFIG_HAVE_64BIT_ALIGNED_STRUCT) || \ + defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) # define RB_FORCE_8BYTE_ALIGNMENT 0 # define RB_ARCH_ALIGNMENT RB_ALIGNMENT #else @@ -185,6 +186,8 @@ void tracing_off_permanent(void) # define RB_ARCH_ALIGNMENT 8U #endif +#define RB_ALIGN_DATA __aligned(RB_ARCH_ALIGNMENT) + /* define RINGBUF_TYPE_DATA for 'case RINGBUF_TYPE_DATA:' */ #define RINGBUF_TYPE_DATA 0 ... RINGBUF_TYPE_DATA_TYPE_LEN_MAX @@ -333,7 +336,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data); struct buffer_data_page { u64 time_stamp; /* page time stamp */ local_t commit; /* write committed index */ - unsigned char data[]; /* data of buffer page */ + unsigned char data[] RB_ALIGN_DATA; /* data of buffer page */ }; /* -- 1.7.7.6