From 1427cdf0592368bdec57276edaf714040ee8744f Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Fri, 6 Mar 2009 17:21:47 +0100 Subject: tracing: infrastructure for supporting binary record Impact: save on memory for tracing Current tracers are typically using a struct(like struct ftrace_entry, struct ctx_switch_entry, struct special_entr etc...)to record a binary event. These structs can only record a their own kind of events. A new kind of tracer need a new struct and a lot of code too handle it. So we need a generic binary record for events. This infrastructure is for this purpose. [fweisbec@gmail.com: rebase against latest -tip, make it safe while sched tracing as reported by Steven Rostedt] Signed-off-by: Lai Jiangshan Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt LKML-Reference: <1236356510-8381-3-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_output.c | 75 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) (limited to 'kernel/trace/trace_output.c') diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 306fef84c503..4ab71201862e 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -53,6 +53,26 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...) return len; } +static int +trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) +{ + int len = (PAGE_SIZE - 1) - s->len; + int ret; + + if (!len) + return 0; + + ret = bstr_printf(s->buffer + s->len, len, fmt, binary); + + /* If we can't write it all, don't bother writing anything */ + if (ret >= len) + return 0; + + s->len += ret; + + return len; +} + /** * trace_seq_puts - trace sequence printing of simple string * @s: trace sequence descriptor @@ -855,6 +875,60 @@ static struct trace_event trace_print_event = { .raw = trace_print_raw, }; +/* TRACE_BPRINTK */ +static enum print_line_t +trace_bprintk_print(struct trace_iterator *iter, int flags) +{ + struct trace_entry *entry = iter->ent; + struct trace_seq *s = &iter->seq; + struct bprintk_entry *field; + + trace_assign_type(field, entry); + + if (!seq_print_ip_sym(s, field->ip, flags)) + goto partial; + + if (!trace_seq_puts(s, ": ")) + goto partial; + + if (!trace_seq_bprintf(s, field->fmt, field->buf)) + goto partial; + + return TRACE_TYPE_HANDLED; + + partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static enum print_line_t +trace_bprintk_raw(struct trace_iterator *iter, int flags) +{ + struct trace_entry *entry = iter->ent; + struct trace_seq *s = &iter->seq; + struct bprintk_entry *field; + + trace_assign_type(field, entry); + + if (!trace_seq_printf(s, ": %lx : ", field->ip)) + goto partial; + + if (!trace_seq_bprintf(s, field->fmt, field->buf)) + goto partial; + + return TRACE_TYPE_HANDLED; + + partial: + return TRACE_TYPE_PARTIAL_LINE; +} + +static struct trace_event trace_bprintk_event = { + .type = TRACE_BPRINTK, + .trace = trace_bprintk_print, + .raw = trace_bprintk_raw, + .hex = trace_nop_print, + .binary = trace_nop_print, +}; + static struct trace_event *events[] __initdata = { &trace_fn_event, &trace_ctx_event, @@ -863,6 +937,7 @@ static struct trace_event *events[] __initdata = { &trace_stack_event, &trace_user_stack_event, &trace_print_event, + &trace_bprintk_event, NULL }; -- cgit v1.2.2