From 884bfe89a462fcc85c8abd96171519cf2fe70929 Mon Sep 17 00:00:00 2001 From: Slava Pestov Date: Fri, 15 Jul 2011 14:23:58 -0700 Subject: ring-buffer: Add a 'dropped events' counter The existing 'overrun' counter is incremented when the ring buffer wraps around, with overflow on (the default). We wanted a way to count requests lost from the buffer filling up with overflow off, too. I decided to add a new counter instead of retro-fitting the existing one because it seems like a different statistic to count conceptually, and also because of how the code was structured. Link: http://lkml.kernel.org/r/1310765038-26399-1-git-send-email-slavapestov@google.com Signed-off-by: Slava Pestov Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 41 +++++++++++++++++++++++++++++++++++------ 1 file changed, 35 insertions(+), 6 deletions(-) (limited to 'kernel/trace/ring_buffer.c') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index b979426d16c..0ebeb1d76dd 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -460,9 +460,10 @@ struct ring_buffer_per_cpu { unsigned long lost_events; unsigned long last_overrun; local_t entries_bytes; - local_t commit_overrun; - local_t overrun; local_t entries; + local_t overrun; + local_t commit_overrun; + local_t dropped_events; local_t committing; local_t commits; unsigned long read; @@ -2155,8 +2156,10 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer, * If we are not in overwrite mode, * this is easy, just stop here. */ - if (!(buffer->flags & RB_FL_OVERWRITE)) + if (!(buffer->flags & RB_FL_OVERWRITE)) { + local_inc(&cpu_buffer->dropped_events); goto out_reset; + } ret = rb_handle_head_page(cpu_buffer, tail_page, @@ -2995,7 +2998,8 @@ unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu) EXPORT_SYMBOL_GPL(ring_buffer_entries_cpu); /** - * ring_buffer_overrun_cpu - get the number of overruns in a cpu_buffer + * ring_buffer_overrun_cpu - get the number of overruns caused by the ring + * buffer wrapping around (only if RB_FL_OVERWRITE is on). * @buffer: The ring buffer * @cpu: The per CPU buffer to get the number of overruns from */ @@ -3015,7 +3019,9 @@ unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu) EXPORT_SYMBOL_GPL(ring_buffer_overrun_cpu); /** - * ring_buffer_commit_overrun_cpu - get the number of overruns caused by commits + * ring_buffer_commit_overrun_cpu - get the number of overruns caused by + * commits failing due to the buffer wrapping around while there are uncommitted + * events, such as during an interrupt storm. * @buffer: The ring buffer * @cpu: The per CPU buffer to get the number of overruns from */ @@ -3035,6 +3041,28 @@ ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu) } EXPORT_SYMBOL_GPL(ring_buffer_commit_overrun_cpu); +/** + * ring_buffer_dropped_events_cpu - get the number of dropped events caused by + * the ring buffer filling up (only if RB_FL_OVERWRITE is off). + * @buffer: The ring buffer + * @cpu: The per CPU buffer to get the number of overruns from + */ +unsigned long +ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + unsigned long ret; + + if (!cpumask_test_cpu(cpu, buffer->cpumask)) + return 0; + + cpu_buffer = buffer->buffers[cpu]; + ret = local_read(&cpu_buffer->dropped_events); + + return ret; +} +EXPORT_SYMBOL_GPL(ring_buffer_dropped_events_cpu); + /** * ring_buffer_entries - get the number of entries in a buffer * @buffer: The ring buffer @@ -3864,9 +3892,10 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) local_set(&cpu_buffer->reader_page->page->commit, 0); cpu_buffer->reader_page->read = 0; - local_set(&cpu_buffer->commit_overrun, 0); local_set(&cpu_buffer->entries_bytes, 0); local_set(&cpu_buffer->overrun, 0); + local_set(&cpu_buffer->commit_overrun, 0); + local_set(&cpu_buffer->dropped_events, 0); local_set(&cpu_buffer->entries, 0); local_set(&cpu_buffer->committing, 0); local_set(&cpu_buffer->commits, 0); -- cgit v1.2.3-70-g09d2 From 01e3e710a9265fb7092efd67243d7b6dd6e2548a Mon Sep 17 00:00:00 2001 From: David Sharp Date: Thu, 7 Jun 2012 16:46:24 -0700 Subject: tracing: Trivial cleanup Remove ftrace_format_syscall() declaration; it is neither defined nor used. Also update a comment and formatting. Link: http://lkml.kernel.org/r/1339112785-21806-1-git-send-email-vnagarnaik@google.com Signed-off-by: David Sharp Signed-off-by: Vaibhav Nagarnaik Signed-off-by: Steven Rostedt --- include/trace/syscall.h | 2 -- kernel/trace/ring_buffer.c | 6 +++--- 2 files changed, 3 insertions(+), 5 deletions(-) (limited to 'kernel/trace/ring_buffer.c') diff --git a/include/trace/syscall.h b/include/trace/syscall.h index 31966a4fb8c..0c95796177d 100644 --- a/include/trace/syscall.h +++ b/include/trace/syscall.h @@ -39,8 +39,6 @@ extern int reg_event_syscall_enter(struct ftrace_event_call *call); extern void unreg_event_syscall_enter(struct ftrace_event_call *call); extern int reg_event_syscall_exit(struct ftrace_event_call *call); extern void unreg_event_syscall_exit(struct ftrace_event_call *call); -extern int -ftrace_format_syscall(struct ftrace_event_call *call, struct trace_seq *s); enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags, struct trace_event *event); enum print_line_t print_syscall_exit(struct trace_iterator *iter, int flags, diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 0ebeb1d76dd..23a384b9251 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1821,7 +1821,7 @@ rb_add_time_stamp(struct ring_buffer_event *event, u64 delta) } /** - * ring_buffer_update_event - update event type and data + * rb_update_event - update event type and data * @event: the even to update * @type: the type of event * @length: the size of the event field in the ring buffer @@ -2723,8 +2723,8 @@ EXPORT_SYMBOL_GPL(ring_buffer_discard_commit); * and not the length of the event which would hold the header. */ int ring_buffer_write(struct ring_buffer *buffer, - unsigned long length, - void *data) + unsigned long length, + void *data) { struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; -- cgit v1.2.3-70-g09d2 From 50ecf2c3afead23a05227ab004e4212eca08c207 Mon Sep 17 00:00:00 2001 From: Yoshihiro YUNOMAE Date: Thu, 11 Oct 2012 16:27:54 -0700 Subject: ring-buffer: Change unsigned long type of ring_buffer_oldest_event_ts() to u64 ring_buffer_oldest_event_ts() should return a value of u64 type, because ring_buffer_per_cpu->buffer_page->buffer_data_page->time_stamp is u64 type. Link: http://lkml.kernel.org/r/1349998076-15495-5-git-send-email-dhsharp@google.com Cc: Frederic Weisbecker Cc: Vaibhav Nagarnaik Signed-off-by: Yoshihiro YUNOMAE Signed-off-by: David Sharp Signed-off-by: Steven Rostedt --- include/linux/ring_buffer.h | 2 +- kernel/trace/ring_buffer.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/trace/ring_buffer.c') diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 2007375cfe7..519777e3fa0 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -159,7 +159,7 @@ int ring_buffer_record_is_on(struct ring_buffer *buffer); void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu); void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu); -unsigned long ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu); +u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_entries(struct ring_buffer *buffer); unsigned long ring_buffer_overruns(struct ring_buffer *buffer); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 23a384b9251..3c7834c24e5 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2932,12 +2932,12 @@ rb_num_of_entries(struct ring_buffer_per_cpu *cpu_buffer) * @buffer: The ring buffer * @cpu: The per CPU buffer to read from. */ -unsigned long ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu) +u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu) { unsigned long flags; struct ring_buffer_per_cpu *cpu_buffer; struct buffer_page *bpage; - unsigned long ret; + u64 ret; if (!cpumask_test_cpu(cpu, buffer->cpumask)) return 0; -- cgit v1.2.3-70-g09d2