From: "Steven Rostedt (Red Hat)" Instead of doing individual checks all over the place that makes the code very messy. Just check trace_seq_has_overflowed() at the end or in strategic places. This makes the code much cleaner and also helps with getting closer to removing the return values of trace_seq_printf() and friends. Link: http://lkml.kernel.org/r/20141114011410.987913836@goodmis.org Reviewed-by: Petr Mladek Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 2 +- kernel/trace/trace_functions_graph.c | 382 +++++++++++------------------------ 2 files changed, 118 insertions(+), 266 deletions(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 19418221b302..c3a37e55ec8b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -726,7 +726,7 @@ extern unsigned long trace_flags; extern enum print_line_t print_graph_function_flags(struct trace_iterator *iter, u32 flags); extern void print_graph_headers_flags(struct seq_file *s, u32 flags); -extern enum print_line_t +extern void trace_print_graph_duration(unsigned long long duration, struct trace_seq *s); extern void graph_trace_open(struct trace_iterator *iter); extern void graph_trace_close(struct trace_iterator *iter); diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 55bdf9d7f714..100288d10e1f 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -107,7 +107,7 @@ enum { FLAGS_FILL_END = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT, }; -static enum print_line_t +static void print_graph_duration(unsigned long long duration, struct trace_seq *s, u32 flags); @@ -483,33 +483,24 @@ static int graph_trace_update_thresh(struct trace_array *tr) static int max_bytes_for_cpu; -static enum print_line_t -print_graph_cpu(struct trace_seq *s, int cpu) +static void print_graph_cpu(struct trace_seq *s, int cpu) { - int ret; - /* * Start with a space character - to make it stand out * to the right a bit when trace output is pasted into * email: */ - ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - return TRACE_TYPE_HANDLED; + trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu); } #define TRACE_GRAPH_PROCINFO_LENGTH 14 -static enum print_line_t -print_graph_proc(struct trace_seq *s, pid_t pid) +static void print_graph_proc(struct trace_seq *s, pid_t pid) { char comm[TASK_COMM_LEN]; /* sign + log10(MAX_INT) + '\0' */ char pid_str[11]; int spaces = 0; - int ret; int len; int i; @@ -524,56 +515,43 @@ print_graph_proc(struct trace_seq *s, pid_t pid) spaces = TRACE_GRAPH_PROCINFO_LENGTH - len; /* First spaces to align center */ - for (i = 0; i < spaces / 2; i++) { - ret = trace_seq_putc(s, ' '); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + for (i = 0; i < spaces / 2; i++) + trace_seq_putc(s, ' '); - ret = trace_seq_printf(s, "%s-%s", comm, pid_str); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + trace_seq_printf(s, "%s-%s", comm, pid_str); /* Last spaces to align center */ - for (i = 0; i < spaces - (spaces / 2); i++) { - ret = trace_seq_putc(s, ' '); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } - return TRACE_TYPE_HANDLED; + for (i = 0; i < spaces - (spaces / 2); i++) + trace_seq_putc(s, ' '); } -static enum print_line_t -print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) +static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) { - if (!trace_seq_putc(s, ' ')) - return 0; - - return trace_print_lat_fmt(s, entry); + trace_seq_putc(s, ' '); + trace_print_lat_fmt(s, entry); } /* If the pid changed since the last trace, output this event */ -static enum print_line_t +static void verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data) { pid_t prev_pid; pid_t *last_pid; - int ret; if (!data) - return TRACE_TYPE_HANDLED; + return; last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); if (*last_pid == pid) - return TRACE_TYPE_HANDLED; + return; prev_pid = *last_pid; *last_pid = pid; if (prev_pid == -1) - return TRACE_TYPE_HANDLED; + return; /* * Context-switch trace line: @@ -582,33 +560,12 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data) ------------------------------------------ */ - ret = trace_seq_puts(s, - " ------------------------------------------\n"); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - ret = print_graph_cpu(s, cpu); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - - ret = print_graph_proc(s, prev_pid); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - - ret = trace_seq_puts(s, " => "); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - ret = print_graph_proc(s, pid); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - - ret = trace_seq_puts(s, - "\n ------------------------------------------\n\n"); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - return TRACE_TYPE_HANDLED; + trace_seq_puts(s, " ------------------------------------------\n"); + print_graph_cpu(s, cpu); + print_graph_proc(s, prev_pid); + trace_seq_puts(s, " => "); + print_graph_proc(s, pid); + trace_seq_puts(s, "\n ------------------------------------------\n\n"); } static struct ftrace_graph_ret_entry * @@ -682,103 +639,74 @@ get_return_for_leaf(struct trace_iterator *iter, return next; } -static int print_graph_abs_time(u64 t, struct trace_seq *s) +static void print_graph_abs_time(u64 t, struct trace_seq *s) { unsigned long usecs_rem; usecs_rem = do_div(t, NSEC_PER_SEC); usecs_rem /= 1000; - return trace_seq_printf(s, "%5lu.%06lu | ", - (unsigned long)t, usecs_rem); + trace_seq_printf(s, "%5lu.%06lu | ", + (unsigned long)t, usecs_rem); } -static enum print_line_t +static void print_graph_irq(struct trace_iterator *iter, unsigned long addr, enum trace_type type, int cpu, pid_t pid, u32 flags) { - int ret; struct trace_seq *s = &iter->seq; struct trace_entry *ent = iter->ent; if (addr < (unsigned long)__irqentry_text_start || addr >= (unsigned long)__irqentry_text_end) - return TRACE_TYPE_UNHANDLED; + return; if (trace_flags & TRACE_ITER_CONTEXT_INFO) { /* Absolute time */ - if (flags & TRACE_GRAPH_PRINT_ABS_TIME) { - ret = print_graph_abs_time(iter->ts, s); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + if (flags & TRACE_GRAPH_PRINT_ABS_TIME) + print_graph_abs_time(iter->ts, s); /* Cpu */ - if (flags & TRACE_GRAPH_PRINT_CPU) { - ret = print_graph_cpu(s, cpu); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - } + if (flags & TRACE_GRAPH_PRINT_CPU) + print_graph_cpu(s, cpu); /* Proc */ if (flags & TRACE_GRAPH_PRINT_PROC) { - ret = print_graph_proc(s, pid); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - ret = trace_seq_puts(s, " | "); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + print_graph_proc(s, pid); + trace_seq_puts(s, " | "); } /* Latency format */ - if (trace_flags & TRACE_ITER_LATENCY_FMT) { - ret = print_graph_lat_fmt(s, ent); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - } - + if (trace_flags & TRACE_ITER_LATENCY_FMT) + print_graph_lat_fmt(s, ent); } /* No overhead */ - ret = print_graph_duration(0, s, flags | FLAGS_FILL_START); - if (ret != TRACE_TYPE_HANDLED) - return ret; + print_graph_duration(0, s, flags | FLAGS_FILL_START); if (type == TRACE_GRAPH_ENT) - ret = trace_seq_puts(s, "==========>"); + trace_seq_puts(s, "==========>"); else - ret = trace_seq_puts(s, "<=========="); - - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - ret = print_graph_duration(0, s, flags | FLAGS_FILL_END); - if (ret != TRACE_TYPE_HANDLED) - return ret; + trace_seq_puts(s, "<=========="); - ret = trace_seq_putc(s, '\n'); - - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - return TRACE_TYPE_HANDLED; + print_graph_duration(0, s, flags | FLAGS_FILL_END); + trace_seq_putc(s, '\n'); } -enum print_line_t +void trace_print_graph_duration(unsigned long long duration, struct trace_seq *s) { unsigned long nsecs_rem = do_div(duration, 1000); /* log10(ULONG_MAX) + '\0' */ char usecs_str[21]; char nsecs_str[5]; - int ret, len; + int len; int i; sprintf(usecs_str, "%lu", (unsigned long) duration); /* Print msecs */ - ret = trace_seq_printf(s, "%s", usecs_str); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + trace_seq_printf(s, "%s", usecs_str); len = strlen(usecs_str); @@ -787,79 +715,63 @@ trace_print_graph_duration(unsigned long long duration, struct trace_seq *s) size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len); snprintf(nsecs_str, slen, "%03lu", nsecs_rem); - ret = trace_seq_printf(s, ".%s", nsecs_str); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + trace_seq_printf(s, ".%s", nsecs_str); len += strlen(nsecs_str); } - ret = trace_seq_puts(s, " us "); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + trace_seq_puts(s, " us "); /* Print remaining spaces to fit the row's width */ - for (i = len; i < 7; i++) { - ret = trace_seq_putc(s, ' '); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } - return TRACE_TYPE_HANDLED; + for (i = len; i < 7; i++) + trace_seq_putc(s, ' '); } -static enum print_line_t +static void print_graph_duration(unsigned long long duration, struct trace_seq *s, u32 flags) { - int ret = -1; + bool duration_printed = false; if (!(flags & TRACE_GRAPH_PRINT_DURATION) || !(trace_flags & TRACE_ITER_CONTEXT_INFO)) - return TRACE_TYPE_HANDLED; + return; /* No real adata, just filling the column with spaces */ switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) { case FLAGS_FILL_FULL: - ret = trace_seq_puts(s, " | "); - return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; + trace_seq_puts(s, " | "); + return; case FLAGS_FILL_START: - ret = trace_seq_puts(s, " "); - return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; + trace_seq_puts(s, " "); + return; case FLAGS_FILL_END: - ret = trace_seq_puts(s, " |"); - return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; + trace_seq_puts(s, " |"); + return; } /* Signal a overhead of time execution to the output */ if (flags & TRACE_GRAPH_PRINT_OVERHEAD) { /* Duration exceeded 100 usecs */ - if (duration > 100000ULL) - ret = trace_seq_puts(s, "! "); + if (duration > 100000ULL) { + trace_seq_puts(s, "! "); + duration_printed = true; + /* Duration exceeded 10 usecs */ - else if (duration > 10000ULL) - ret = trace_seq_puts(s, "+ "); + } else if (duration > 10000ULL) { + trace_seq_puts(s, "+ "); + duration_printed = true; + } } /* - * The -1 means we either did not exceed the duration tresholds - * or we dont want to print out the overhead. Either way we need - * to fill out the space. + * If we did not exceed the duration tresholds or we dont want + * to print out the overhead. Either way we need to fill out the space. */ - if (ret == -1) - ret = trace_seq_puts(s, " "); - - /* Catching here any failure happenned above */ - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - ret = trace_print_graph_duration(duration, s); - if (ret != TRACE_TYPE_HANDLED) - return ret; + if (!duration_printed) + trace_seq_puts(s, " "); - ret = trace_seq_puts(s, "| "); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - - return TRACE_TYPE_HANDLED; + trace_print_graph_duration(duration, s); + trace_seq_puts(s, "| "); } /* Case of a leaf function on its call entry */ @@ -873,7 +785,6 @@ print_graph_entry_leaf(struct trace_iterator *iter, struct ftrace_graph_ret *graph_ret; struct ftrace_graph_ent *call; unsigned long long duration; - int ret; int i; graph_ret = &ret_entry->ret; @@ -899,22 +810,15 @@ print_graph_entry_leaf(struct trace_iterator *iter, } /* Overhead and duration */ - ret = print_graph_duration(duration, s, flags); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; + print_graph_duration(duration, s, flags); /* Function */ - for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) { - ret = trace_seq_putc(s, ' '); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) + trace_seq_putc(s, ' '); - ret = trace_seq_printf(s, "%ps();\n", (void *)call->func); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + trace_seq_printf(s, "%ps();\n", (void *)call->func); - return TRACE_TYPE_HANDLED; + return trace_handle_return(s); } static enum print_line_t @@ -924,7 +828,6 @@ print_graph_entry_nested(struct trace_iterator *iter, { struct ftrace_graph_ent *call = &entry->graph_ent; struct fgraph_data *data = iter->private; - int ret; int i; if (data) { @@ -940,19 +843,15 @@ print_graph_entry_nested(struct trace_iterator *iter, } /* No time */ - ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL); - if (ret != TRACE_TYPE_HANDLED) - return ret; + print_graph_duration(0, s, flags | FLAGS_FILL_FULL); /* Function */ - for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) { - ret = trace_seq_putc(s, ' '); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) + trace_seq_putc(s, ' '); + + trace_seq_printf(s, "%ps() {\n", (void *)call->func); - ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func); - if (!ret) + if (trace_seq_has_overflowed(s)) return TRACE_TYPE_PARTIAL_LINE; /* @@ -962,62 +861,43 @@ print_graph_entry_nested(struct trace_iterator *iter, return TRACE_TYPE_NO_CONSUME; } -static enum print_line_t +static void print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s, int type, unsigned long addr, u32 flags) { struct fgraph_data *data = iter->private; struct trace_entry *ent = iter->ent; int cpu = iter->cpu; - int ret; /* Pid */ - if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; + verif_pid(s, ent->pid, cpu, data); - if (type) { + if (type) /* Interrupt */ - ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - } + print_graph_irq(iter, addr, type, cpu, ent->pid, flags); if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) - return 0; + return; /* Absolute time */ - if (flags & TRACE_GRAPH_PRINT_ABS_TIME) { - ret = print_graph_abs_time(iter->ts, s); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + if (flags & TRACE_GRAPH_PRINT_ABS_TIME) + print_graph_abs_time(iter->ts, s); /* Cpu */ - if (flags & TRACE_GRAPH_PRINT_CPU) { - ret = print_graph_cpu(s, cpu); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - } + if (flags & TRACE_GRAPH_PRINT_CPU) + print_graph_cpu(s, cpu); /* Proc */ if (flags & TRACE_GRAPH_PRINT_PROC) { - ret = print_graph_proc(s, ent->pid); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - - ret = trace_seq_puts(s, " | "); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + print_graph_proc(s, ent->pid); + trace_seq_puts(s, " | "); } /* Latency format */ - if (trace_flags & TRACE_ITER_LATENCY_FMT) { - ret = print_graph_lat_fmt(s, ent); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; - } + if (trace_flags & TRACE_ITER_LATENCY_FMT) + print_graph_lat_fmt(s, ent); - return 0; + return; } /* @@ -1135,8 +1015,7 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s, if (check_irq_entry(iter, flags, call->func, call->depth)) return TRACE_TYPE_HANDLED; - if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags)) - return TRACE_TYPE_PARTIAL_LINE; + print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags); leaf_ret = get_return_for_leaf(iter, field); if (leaf_ret) @@ -1169,7 +1048,6 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, pid_t pid = ent->pid; int cpu = iter->cpu; int func_match = 1; - int ret; int i; if (check_irq_return(iter, flags, trace->depth)) @@ -1195,20 +1073,14 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, } } - if (print_graph_prologue(iter, s, 0, 0, flags)) - return TRACE_TYPE_PARTIAL_LINE; + print_graph_prologue(iter, s, 0, 0, flags); /* Overhead and duration */ - ret = print_graph_duration(duration, s, flags); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; + print_graph_duration(duration, s, flags); /* Closing brace */ - for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) { - ret = trace_seq_putc(s, ' '); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) + trace_seq_putc(s, ' '); /* * If the return function does not have a matching entry, @@ -1217,30 +1089,20 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, * belongs to, write out the function name. Always do * that if the funcgraph-tail option is enabled. */ - if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL)) { - ret = trace_seq_puts(s, "}\n"); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } else { - ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL)) + trace_seq_puts(s, "}\n"); + else + trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func); /* Overrun */ - if (flags & TRACE_GRAPH_PRINT_OVERRUN) { - ret = trace_seq_printf(s, " (Overruns: %lu)\n", - trace->overrun); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + if (flags & TRACE_GRAPH_PRINT_OVERRUN) + trace_seq_printf(s, " (Overruns: %lu)\n", + trace->overrun); - ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, - cpu, pid, flags); - if (ret == TRACE_TYPE_PARTIAL_LINE) - return TRACE_TYPE_PARTIAL_LINE; + print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, + cpu, pid, flags); - return TRACE_TYPE_HANDLED; + return trace_handle_return(s); } static enum print_line_t @@ -1257,26 +1119,18 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent, if (data) depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth; - if (print_graph_prologue(iter, s, 0, 0, flags)) - return TRACE_TYPE_PARTIAL_LINE; + print_graph_prologue(iter, s, 0, 0, flags); /* No time */ - ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL); - if (ret != TRACE_TYPE_HANDLED) - return ret; + print_graph_duration(0, s, flags | FLAGS_FILL_FULL); /* Indentation */ if (depth > 0) - for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) { - ret = trace_seq_putc(s, ' '); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - } + for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) + trace_seq_putc(s, ' '); /* The comment */ - ret = trace_seq_puts(s, "/* "); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + trace_seq_puts(s, "/* "); switch (iter->ent->type) { case TRACE_BPRINT: @@ -1305,11 +1159,9 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent, s->len--; } - ret = trace_seq_puts(s, " */\n"); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; + trace_seq_puts(s, " */\n"); - return TRACE_TYPE_HANDLED; + return trace_handle_return(s); } -- 2.1.1