diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 88 |
1 files changed, 47 insertions, 41 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 78ea542ce3bc..a569a0cb81ee 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -980,6 +980,8 @@ __buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *ev ring_buffer_write(buffer, event->array[0], &event->array[1]); /* Release the temp buffer */ this_cpu_dec(trace_buffered_event_cnt); + /* ring_buffer_unlock_commit() enables preemption */ + preempt_enable_notrace(); } else ring_buffer_unlock_commit(buffer, event); } @@ -2601,6 +2603,8 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status) trace_flags |= TRACE_FLAG_HARDIRQ; if (in_serving_softirq()) trace_flags |= TRACE_FLAG_SOFTIRQ; + if (softirq_count() >> (SOFTIRQ_SHIFT + 1)) + trace_flags |= TRACE_FLAG_BH_OFF; if (tif_need_resched()) trace_flags |= TRACE_FLAG_NEED_RESCHED; @@ -2745,8 +2749,8 @@ trace_event_buffer_lock_reserve(struct trace_buffer **current_rb, *current_rb = tr->array_buffer.buffer; if (!tr->no_filter_buffering_ref && - (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) && - (entry = this_cpu_read(trace_buffered_event))) { + (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED))) { + preempt_disable_notrace(); /* * Filtering is on, so try to use the per cpu buffer first. * This buffer will simulate a ring_buffer_event, @@ -2764,33 +2768,38 @@ trace_event_buffer_lock_reserve(struct trace_buffer **current_rb, * is still quicker than no copy on match, but having * to discard out of the ring buffer on a failed match. */ - int max_len = PAGE_SIZE - struct_size(entry, array, 1); + if ((entry = __this_cpu_read(trace_buffered_event))) { + int max_len = PAGE_SIZE - struct_size(entry, array, 1); - val = this_cpu_inc_return(trace_buffered_event_cnt); + val = this_cpu_inc_return(trace_buffered_event_cnt); - /* - * Preemption is disabled, but interrupts and NMIs - * can still come in now. If that happens after - * the above increment, then it will have to go - * back to the old method of allocating the event - * on the ring buffer, and if the filter fails, it - * will have to call ring_buffer_discard_commit() - * to remove it. - * - * Need to also check the unlikely case that the - * length is bigger than the temp buffer size. - * If that happens, then the reserve is pretty much - * guaranteed to fail, as the ring buffer currently - * only allows events less than a page. But that may - * change in the future, so let the ring buffer reserve - * handle the failure in that case. - */ - if (val == 1 && likely(len <= max_len)) { - trace_event_setup(entry, type, trace_ctx); - entry->array[0] = len; - return entry; + /* + * Preemption is disabled, but interrupts and NMIs + * can still come in now. If that happens after + * the above increment, then it will have to go + * back to the old method of allocating the event + * on the ring buffer, and if the filter fails, it + * will have to call ring_buffer_discard_commit() + * to remove it. + * + * Need to also check the unlikely case that the + * length is bigger than the temp buffer size. + * If that happens, then the reserve is pretty much + * guaranteed to fail, as the ring buffer currently + * only allows events less than a page. But that may + * change in the future, so let the ring buffer reserve + * handle the failure in that case. + */ + if (val == 1 && likely(len <= max_len)) { + trace_event_setup(entry, type, trace_ctx); + entry->array[0] = len; + /* Return with preemption disabled */ + return entry; + } + this_cpu_dec(trace_buffered_event_cnt); } - this_cpu_dec(trace_buffered_event_cnt); + /* __trace_buffer_lock_reserve() disables preemption */ + preempt_enable_notrace(); } entry = __trace_buffer_lock_reserve(*current_rb, type, len, @@ -4183,7 +4192,7 @@ unsigned long trace_total_entries(struct trace_array *tr) static void print_lat_help_header(struct seq_file *m) { seq_puts(m, "# _------=> CPU# \n" - "# / _-----=> irqs-off \n" + "# / _-----=> irqs-off/BH-disabled\n" "# | / _----=> need-resched \n" "# || / _---=> hardirq/softirq \n" "# ||| / _--=> preempt-depth \n" @@ -4224,7 +4233,7 @@ static void print_func_help_header_irq(struct array_buffer *buf, struct seq_file print_event_info(buf, m); - seq_printf(m, "# %.*s _-----=> irqs-off\n", prec, space); + seq_printf(m, "# %.*s _-----=> irqs-off/BH-disabled\n", prec, space); seq_printf(m, "# %.*s / _----=> need-resched\n", prec, space); seq_printf(m, "# %.*s| / _---=> hardirq/softirq\n", prec, space); seq_printf(m, "# %.*s|| / _--=> preempt-depth\n", prec, space); @@ -4834,6 +4843,12 @@ int tracing_open_generic_tr(struct inode *inode, struct file *filp) return 0; } +static int tracing_mark_open(struct inode *inode, struct file *filp) +{ + stream_open(inode, filp); + return tracing_open_generic_tr(inode, filp); +} + static int tracing_release(struct inode *inode, struct file *file) { struct trace_array *tr = inode->i_private; @@ -5635,7 +5650,7 @@ static const char readme_msg[] = "\t - a numeric literal: e.g. ms_per_sec=1000,\n" "\t - an arithmetic expression: e.g. time_secs=current_timestamp/1000\n" "\n" - "\t hist trigger aritmethic expressions support addition(+), subtraction(-),\n" + "\t hist trigger arithmetic expressions support addition(+), subtraction(-),\n" "\t multiplication(*) and division(/) operators. An operand can be either a\n" "\t variable reference, field or numeric literal.\n" "\n" @@ -6718,10 +6733,9 @@ waitagain: cnt = PAGE_SIZE - 1; /* reset all but tr, trace, and overruns */ - memset_startat(iter, 0, seq); + trace_iterator_reset(iter); cpumask_clear(iter->started); trace_seq_init(&iter->seq); - iter->pos = -1; trace_event_read_lock(); trace_access_lock(iter->cpu_file); @@ -7110,9 +7124,6 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, if (tt) event_triggers_post_call(tr->trace_marker_file, tt); - if (written > 0) - *fpos += written; - return written; } @@ -7171,9 +7182,6 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf, __buffer_unlock_commit(buffer, event); - if (written > 0) - *fpos += written; - return written; } @@ -7573,16 +7581,14 @@ static const struct file_operations tracing_free_buffer_fops = { }; static const struct file_operations tracing_mark_fops = { - .open = tracing_open_generic_tr, + .open = tracing_mark_open, .write = tracing_mark_write, - .llseek = generic_file_llseek, .release = tracing_release_generic_tr, }; static const struct file_operations tracing_mark_raw_fops = { - .open = tracing_open_generic_tr, + .open = tracing_mark_open, .write = tracing_mark_raw_write, - .llseek = generic_file_llseek, .release = tracing_release_generic_tr, }; |