From: Steven Rostedt Date: Mon, 12 May 2008 19:20:46 +0000 (+0200) Subject: ftrace: add a buffer for output X-Git-Tag: v2.6.27-rc1~1102^2^2~1^2~122 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=214023c3d13a71525e463b5e54e360b926b4dc90;p=linux-2.6 ftrace: add a buffer for output Later patches will need to print the same things as the seq output does. But those outputs will not use the seq utility. This patch adds a buffer to the iterator, that can be used by either the seq utility or other output. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 777b859e1c..d39f4faec7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -169,6 +169,66 @@ void *head_page(struct trace_array_cpu *data) return page_address(page); } +static notrace int +trace_seq_printf(struct trace_seq *s, const char *fmt, ...) +{ + int len = (PAGE_SIZE - 1) - s->len; + va_list ap; + + if (!len) + return 0; + + va_start(ap, fmt); + len = vsnprintf(s->buffer + s->len, len, fmt, ap); + va_end(ap); + + s->len += len; + + return len; +} + +static notrace int +trace_seq_puts(struct trace_seq *s, const char *str) +{ + int len = strlen(str); + + if (len > ((PAGE_SIZE - 1) - s->len)) + len = (PAGE_SIZE - 1) - s->len; + + memcpy(s->buffer + s->len, str, len); + s->len += len; + + return len; +} + +static notrace int +trace_seq_putc(struct trace_seq *s, unsigned char c) +{ + if (s->len >= (PAGE_SIZE - 1)) + return 0; + + s->buffer[s->len++] = c; + + return 1; +} + +static notrace void +trace_seq_reset(struct trace_seq *s) +{ + s->len = 0; +} + +static notrace void +trace_print_seq(struct seq_file *m, struct trace_seq *s) +{ + int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; + + s->buffer[len] = 0; + seq_puts(m, s->buffer); + + trace_seq_reset(s); +} + notrace static void flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) { @@ -756,25 +816,26 @@ static void s_stop(struct seq_file *m, void *p) } static void -seq_print_sym_short(struct seq_file *m, const char *fmt, unsigned long address) +seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address) { #ifdef CONFIG_KALLSYMS char str[KSYM_SYMBOL_LEN]; kallsyms_lookup(address, NULL, NULL, NULL, str); - seq_printf(m, fmt, str); + trace_seq_printf(s, fmt, str); #endif } static void -seq_print_sym_offset(struct seq_file *m, const char *fmt, unsigned long address) +seq_print_sym_offset(struct trace_seq *s, const char *fmt, + unsigned long address) { #ifdef CONFIG_KALLSYMS char str[KSYM_SYMBOL_LEN]; sprint_symbol(str, address); - seq_printf(m, fmt, str); + trace_seq_printf(s, fmt, str); #endif } @@ -785,20 +846,20 @@ seq_print_sym_offset(struct seq_file *m, const char *fmt, unsigned long address) #endif static notrace void -seq_print_ip_sym(struct seq_file *m, unsigned long ip, unsigned long sym_flags) +seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) { if (!ip) { - seq_printf(m, "0"); + trace_seq_printf(s, "0"); return; } if (sym_flags & TRACE_ITER_SYM_OFFSET) - seq_print_sym_offset(m, "%s", ip); + seq_print_sym_offset(s, "%s", ip); else - seq_print_sym_short(m, "%s", ip); + seq_print_sym_short(s, "%s", ip); if (sym_flags & TRACE_ITER_SYM_ADDR) - seq_printf(m, " <" IP_FMT ">", ip); + trace_seq_printf(s, " <" IP_FMT ">", ip); } static notrace void print_lat_help_header(struct seq_file *m) @@ -881,9 +942,11 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) if (data->critical_start) { seq_puts(m, " => started at: "); - seq_print_ip_sym(m, data->critical_start, sym_flags); + seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); + trace_print_seq(m, &iter->seq); seq_puts(m, "\n => ended at: "); - seq_print_ip_sym(m, data->critical_end, sym_flags); + seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); + trace_print_seq(m, &iter->seq); seq_puts(m, "\n"); } @@ -891,61 +954,61 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) } static notrace void -lat_print_generic(struct seq_file *m, struct trace_entry *entry, int cpu) +lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) { int hardirq, softirq; char *comm; comm = trace_find_cmdline(entry->pid); - seq_printf(m, "%8.8s-%-5d ", comm, entry->pid); - seq_printf(m, "%d", cpu); - seq_printf(m, "%c%c", - (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', - ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); + trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); + trace_seq_printf(s, "%d", cpu); + trace_seq_printf(s, "%c%c", + (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', + ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); hardirq = entry->flags & TRACE_FLAG_HARDIRQ; softirq = entry->flags & TRACE_FLAG_SOFTIRQ; if (hardirq && softirq) - seq_putc(m, 'H'); + trace_seq_putc(s, 'H'); else { if (hardirq) - seq_putc(m, 'h'); + trace_seq_putc(s, 'h'); else { if (softirq) - seq_putc(m, 's'); + trace_seq_putc(s, 's'); else - seq_putc(m, '.'); + trace_seq_putc(s, '.'); } } if (entry->preempt_count) - seq_printf(m, "%x", entry->preempt_count); + trace_seq_printf(s, "%x", entry->preempt_count); else - seq_puts(m, "."); + trace_seq_puts(s, "."); } unsigned long preempt_mark_thresh = 100; static notrace void -lat_print_timestamp(struct seq_file *m, unsigned long long abs_usecs, +lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, unsigned long rel_usecs) { - seq_printf(m, " %4lldus", abs_usecs); + trace_seq_printf(s, " %4lldus", abs_usecs); if (rel_usecs > preempt_mark_thresh) - seq_puts(m, "!: "); + trace_seq_puts(s, "!: "); else if (rel_usecs > 1) - seq_puts(m, "+: "); + trace_seq_puts(s, "+: "); else - seq_puts(m, " : "); + trace_seq_puts(s, " : "); } static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; static notrace void -print_lat_fmt(struct seq_file *m, struct trace_iterator *iter, - unsigned int trace_idx, int cpu) +print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) { + struct trace_seq *s = &iter->seq; unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); struct trace_entry *next_entry = find_next_entry(iter, NULL); unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); @@ -962,39 +1025,40 @@ print_lat_fmt(struct seq_file *m, struct trace_iterator *iter, if (verbose) { comm = trace_find_cmdline(entry->pid); - seq_printf(m, "%16s %5d %d %d %08x %08x [%08lx]" - " %ld.%03ldms (+%ld.%03ldms): ", - comm, - entry->pid, cpu, entry->flags, - entry->preempt_count, trace_idx, - ns2usecs(entry->t), - abs_usecs/1000, - abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000); + trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]" + " %ld.%03ldms (+%ld.%03ldms): ", + comm, + entry->pid, cpu, entry->flags, + entry->preempt_count, trace_idx, + ns2usecs(entry->t), + abs_usecs/1000, + abs_usecs % 1000, rel_usecs/1000, + rel_usecs % 1000); } else { - lat_print_generic(m, entry, cpu); - lat_print_timestamp(m, abs_usecs, rel_usecs); + lat_print_generic(s, entry, cpu); + lat_print_timestamp(s, abs_usecs, rel_usecs); } switch (entry->type) { case TRACE_FN: - seq_print_ip_sym(m, entry->fn.ip, sym_flags); - seq_puts(m, " ("); - seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags); - seq_puts(m, ")\n"); + seq_print_ip_sym(s, entry->fn.ip, sym_flags); + trace_seq_puts(s, " ("); + seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); + trace_seq_puts(s, ")\n"); break; case TRACE_CTX: S = entry->ctx.prev_state < sizeof(state_to_char) ? state_to_char[entry->ctx.prev_state] : 'X'; comm = trace_find_cmdline(entry->ctx.next_pid); - seq_printf(m, " %d:%d:%c --> %d:%d %s\n", - entry->ctx.prev_pid, - entry->ctx.prev_prio, - S, - entry->ctx.next_pid, - entry->ctx.next_prio, - comm); + trace_seq_printf(s, " %d:%d:%c --> %d:%d %s\n", + entry->ctx.prev_pid, + entry->ctx.prev_prio, + S, + entry->ctx.next_pid, + entry->ctx.next_prio, + comm); break; default: - seq_printf(m, "Unknown type %d\n", entry->type); + trace_seq_printf(s, "Unknown type %d\n", entry->type); } } @@ -1026,8 +1090,9 @@ static notrace void sync_time_offset(struct trace_iterator *iter) } static notrace void -print_trace_fmt(struct seq_file *m, struct trace_iterator *iter) +print_trace_fmt(struct trace_iterator *iter) { + struct trace_seq *s = &iter->seq; unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); struct trace_entry *entry; unsigned long usec_rem; @@ -1045,29 +1110,29 @@ print_trace_fmt(struct seq_file *m, struct trace_iterator *iter) usec_rem = do_div(t, 1000000ULL); secs = (unsigned long)t; - seq_printf(m, "%16s-%-5d ", comm, entry->pid); - seq_printf(m, "[%02d] ", iter->cpu); - seq_printf(m, "%5lu.%06lu: ", secs, usec_rem); + trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); + trace_seq_printf(s, "[%02d] ", iter->cpu); + trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem); switch (entry->type) { case TRACE_FN: - seq_print_ip_sym(m, entry->fn.ip, sym_flags); + seq_print_ip_sym(s, entry->fn.ip, sym_flags); if ((sym_flags & TRACE_ITER_PRINT_PARENT) && entry->fn.parent_ip) { - seq_printf(m, " <-"); - seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags); + trace_seq_printf(s, " <-"); + seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); } - seq_printf(m, "\n"); + trace_seq_printf(s, "\n"); break; case TRACE_CTX: S = entry->ctx.prev_state < sizeof(state_to_char) ? state_to_char[entry->ctx.prev_state] : 'X'; - seq_printf(m, " %d:%d:%c ==> %d:%d\n", - entry->ctx.prev_pid, - entry->ctx.prev_prio, - S, - entry->ctx.next_pid, - entry->ctx.next_prio); + trace_seq_printf(s, " %d:%d:%c ==> %d:%d\n", + entry->ctx.prev_pid, + entry->ctx.prev_prio, + S, + entry->ctx.next_pid, + entry->ctx.next_prio); break; } } @@ -1108,9 +1173,10 @@ static int s_show(struct seq_file *m, void *v) } } else { if (iter->iter_flags & TRACE_FILE_LAT_FMT) - print_lat_fmt(m, iter, iter->idx, iter->cpu); + print_lat_fmt(iter, iter->idx, iter->cpu); else - print_trace_fmt(m, iter); + print_trace_fmt(iter); + trace_print_seq(m, &iter->seq); } return 0; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 0ce127455b..f5b32ca0b4 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -111,11 +111,17 @@ struct tracer { int print_max; }; +struct trace_seq { + unsigned char buffer[PAGE_SIZE]; + unsigned int len; +}; + /* * Trace iterator - used by printout routines who present trace * results to users and which routines might sleep, etc: */ struct trace_iterator { + struct trace_seq seq; struct trace_array *tr; struct tracer *trace;