From d8eeb2d3b26d25c44c10f28430e2157a2d20bd1d Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Fri, 31 Jul 2009 14:58:04 +0200 Subject: ring-buffer: consolidate interface of rb_buffer_peek() rb_buffer_peek() operates with struct ring_buffer_per_cpu *cpu_buffer only. Thus, instead of passing variables buffer and cpu it is better to use cpu_buffer directly. This also reduces the risk of races since cpu_buffer is not calculated twice. Signed-off-by: Robert Richter LKML-Reference: <1249045084-3028-1-git-send-email-robert.richter@amd.com> Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'kernel/trace/ring_buffer.c') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 454e74e718cf..8786c350b4ca 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2997,15 +2997,12 @@ static void rb_advance_iter(struct ring_buffer_iter *iter) } static struct ring_buffer_event * -rb_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) +rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts) { - struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; struct buffer_page *reader; int nr_loops = 0; - cpu_buffer = buffer->buffers[cpu]; - again: /* * We repeat when a timestamp is encountered. It is possible @@ -3049,7 +3046,7 @@ rb_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) case RINGBUF_TYPE_DATA: if (ts) { *ts = cpu_buffer->read_stamp + event->time_delta; - ring_buffer_normalize_time_stamp(buffer, + ring_buffer_normalize_time_stamp(cpu_buffer->buffer, cpu_buffer->cpu, ts); } return event; @@ -3168,7 +3165,7 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) local_irq_save(flags); if (dolock) spin_lock(&cpu_buffer->reader_lock); - event = rb_buffer_peek(buffer, cpu, ts); + event = rb_buffer_peek(cpu_buffer, ts); if (event && event->type_len == RINGBUF_TYPE_PADDING) rb_advance_reader(cpu_buffer); if (dolock) @@ -3237,7 +3234,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts) if (dolock) spin_lock(&cpu_buffer->reader_lock); - event = rb_buffer_peek(buffer, cpu, ts); + event = rb_buffer_peek(cpu_buffer, ts); if (event) rb_advance_reader(cpu_buffer); -- cgit v1.2.2 From 08a408161749d2406f94f4e3d47cfdbc826ad1cc Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 14 Sep 2009 09:31:35 -0400 Subject: ring-buffer: typecast cmpxchg to fix PowerPC warning The cmpxchg used by PowerPC does the following: ({ \ __typeof__(*(ptr)) _o_ = (o); \ __typeof__(*(ptr)) _n_ = (n); \ (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ (unsigned long)_n_, sizeof(*(ptr))); \ }) This does a type check of *ptr to both o and n. Unfortunately, the code in ring-buffer.c assigns longs to pointers and pointers to longs and causes a warning on PowerPC: ring_buffer.c: In function 'rb_head_page_set': ring_buffer.c:704: warning: initialization makes pointer from integer without a cast ring_buffer.c:704: warning: initialization makes pointer from integer without a cast ring_buffer.c: In function 'rb_head_page_replace': ring_buffer.c:797: warning: initialization makes integer from pointer without a cast This patch adds the typecasts inside cmpxchg to annotate that a long is being cast to a pointer and a pointer is being casted to a long and this removes the PowerPC warnings. Reported-by: Stephen Rothwell Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/trace/ring_buffer.c') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 8786c350b4ca..6eef38923b07 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -701,8 +701,8 @@ static int rb_head_page_set(struct ring_buffer_per_cpu *cpu_buffer, val &= ~RB_FLAG_MASK; - ret = (unsigned long)cmpxchg(&list->next, - val | old_flag, val | new_flag); + ret = cmpxchg((unsigned long *)&list->next, + val | old_flag, val | new_flag); /* check if the reader took the page */ if ((ret & ~RB_FLAG_MASK) != val) @@ -794,7 +794,7 @@ static int rb_head_page_replace(struct buffer_page *old, val = *ptr & ~RB_FLAG_MASK; val |= RB_PAGE_HEAD; - ret = cmpxchg(ptr, val, &new->list); + ret = cmpxchg(ptr, val, (unsigned long)&new->list); return ret == val; } -- cgit v1.2.2 From a0f320f48799f67329fcb1b26ff0451c304e1dde Mon Sep 17 00:00:00 2001 From: Jaswinder Singh Rajput Date: Sun, 20 Sep 2009 16:31:16 +0530 Subject: includecheck fix: kernel/trace, ring_buffer.c fix the following 'make includecheck' warning: kernel/trace/ring_buffer.c: trace.h is included more than once. Signed-off-by: Jaswinder Singh Rajput Cc: Steven Rostedt Cc: Ingo Molnar Cc: Sam Ravnborg LKML-Reference: <1247068617.4382.107.camel@ht.satnam> --- kernel/trace/ring_buffer.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/trace/ring_buffer.c') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 6eef38923b07..d4ff01970547 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -201,8 +201,6 @@ int tracing_is_on(void) } EXPORT_SYMBOL_GPL(tracing_is_on); -#include "trace.h" - #define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array)) #define RB_ALIGNMENT 4U #define RB_MAX_SMALL_DATA (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX) -- cgit v1.2.2