From 30350d65ac5676c6d08d4fc935bc9a9cb0fd4ed3 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 15 Jan 2018 20:51:49 -0600 Subject: [PATCH] tracing: Add variable support to hist triggers Add support for saving the value of a current event's event field by assigning it to a variable that can be read by a subsequent event. The basic syntax for saving a variable is to simply prefix a unique variable name not corresponding to any keyword along with an '=' sign to any event field. Both keys and values can be saved and retrieved in this way: # echo 'hist:keys=next_pid:vals=$ts0:ts0=common_timestamp ... # echo 'hist:timer_pid=common_pid:key=$timer_pid ...' If a variable isn't a key variable or prefixed with 'vals=', the associated event field will be saved in a variable but won't be summed as a value: # echo 'hist:keys=next_pid:ts1=common_timestamp:... Multiple variables can be assigned at the same time: # echo 'hist:keys=pid:vals=$ts0,$b,field2:ts0=common_timestamp,b=field1 ... Multiple (or single) variables can also be assigned at the same time using separate assignments: # echo 'hist:keys=pid:vals=$ts0:ts0=common_timestamp:b=field1:c=field2 ... Variables set as above can be used by being referenced from another event, as described in a subsequent patch. Link: http://lkml.kernel.org/r/fc93c4944d9719dbcb1d0067be627d44e98e2adc.1516069914.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Baohong Liu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_hist.c | 370 +++++++++++++++++++++++++++---- 1 file changed, 331 insertions(+), 39 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 7f5f0b8f6558..8f43f24bf49c 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -30,6 +30,13 @@ typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event, struct ring_buffer_event *rbe); #define HIST_FIELD_OPERANDS_MAX 2 +#define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX) + +struct hist_var { + char *name; + struct hist_trigger_data *hist_data; + unsigned int idx; +}; struct hist_field { struct ftrace_event_field *field; @@ -40,6 +47,7 @@ struct hist_field { unsigned int is_signed; struct hist_field *operands[HIST_FIELD_OPERANDS_MAX]; struct hist_trigger_data *hist_data; + struct hist_var var; }; static u64 hist_field_none(struct hist_field *field, void *event, @@ -138,6 +146,13 @@ enum hist_field_flags { HIST_FIELD_FL_LOG2 = 1 << 9, HIST_FIELD_FL_TIMESTAMP = 1 << 10, HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11, + HIST_FIELD_FL_VAR = 1 << 12, +}; + +struct var_defs { + unsigned int n_vars; + char *name[TRACING_MAP_VARS_MAX]; + char *expr[TRACING_MAP_VARS_MAX]; }; struct hist_trigger_attrs { @@ -150,13 +165,19 @@ struct hist_trigger_attrs { bool clear; bool ts_in_usecs; unsigned int map_bits; + + char *assignment_str[TRACING_MAP_VARS_MAX]; + unsigned int n_assignments; + + struct var_defs var_defs; }; struct hist_trigger_data { - struct hist_field *fields[TRACING_MAP_FIELDS_MAX]; + struct hist_field *fields[HIST_FIELDS_MAX]; unsigned int n_vals; unsigned int n_keys; unsigned int n_fields; + unsigned int n_vars; unsigned int key_size; struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX]; unsigned int n_sort_keys; @@ -164,6 +185,7 @@ struct hist_trigger_data { struct hist_trigger_attrs *attrs; struct tracing_map *map; bool enable_timestamps; + bool remove; }; static u64 hist_field_timestamp(struct hist_field *hist_field, void *event, @@ -180,6 +202,48 @@ static u64 hist_field_timestamp(struct hist_field *hist_field, void *event, return ts; } +static struct hist_field *find_var_field(struct hist_trigger_data *hist_data, + const char *var_name) +{ + struct hist_field *hist_field, *found = NULL; + int i; + + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR && + strcmp(hist_field->var.name, var_name) == 0) { + found = hist_field; + break; + } + } + + return found; +} + +static struct hist_field *find_var(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + const char *var_name) +{ + struct hist_trigger_data *test_data; + struct event_trigger_data *test; + struct hist_field *hist_field; + + hist_field = find_var_field(hist_data, var_name); + if (hist_field) + return hist_field; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + test_data = test->private_data; + hist_field = find_var_field(test_data, var_name); + if (hist_field) + return hist_field; + } + } + + return NULL; +} + static const char *hist_field_name(struct hist_field *field, unsigned int level) { @@ -262,9 +326,14 @@ static int parse_map_size(char *str) static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) { + unsigned int i; + if (!attrs) return; + for (i = 0; i < attrs->n_assignments; i++) + kfree(attrs->assignment_str[i]); + kfree(attrs->name); kfree(attrs->sort_key_str); kfree(attrs->keys_str); @@ -311,8 +380,22 @@ static int parse_assignment(char *str, struct hist_trigger_attrs *attrs) goto out; } attrs->map_bits = map_bits; - } else - ret = -EINVAL; + } else { + char *assignment; + + if (attrs->n_assignments == TRACING_MAP_VARS_MAX) { + ret = -EINVAL; + goto out; + } + + assignment = kstrdup(str, GFP_KERNEL); + if (!assignment) { + ret = -ENOMEM; + goto out; + } + + attrs->assignment_str[attrs->n_assignments++] = assignment; + } out: return ret; } @@ -428,12 +511,15 @@ static void destroy_hist_field(struct hist_field *hist_field, for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) destroy_hist_field(hist_field->operands[i], level + 1); + kfree(hist_field->var.name); + kfree(hist_field); } static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, struct ftrace_event_field *field, - unsigned long flags) + unsigned long flags, + char *var_name) { struct hist_field *hist_field; @@ -459,7 +545,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, if (flags & HIST_FIELD_FL_LOG2) { unsigned long fl = flags & ~HIST_FIELD_FL_LOG2; hist_field->fn = hist_field_log2; - hist_field->operands[0] = create_hist_field(hist_data, field, fl); + hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL); hist_field->size = hist_field->operands[0]->size; goto out; } @@ -494,14 +580,23 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, hist_field->field = field; hist_field->flags = flags; + if (var_name) { + hist_field->var.name = kstrdup(var_name, GFP_KERNEL); + if (!hist_field->var.name) + goto free; + } + return hist_field; + free: + destroy_hist_field(hist_field, 0); + return NULL; } static void destroy_hist_fields(struct hist_trigger_data *hist_data) { unsigned int i; - for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) { + for (i = 0; i < HIST_FIELDS_MAX; i++) { if (hist_data->fields[i]) { destroy_hist_field(hist_data->fields[i], 0); hist_data->fields[i] = NULL; @@ -512,11 +607,12 @@ static void destroy_hist_fields(struct hist_trigger_data *hist_data) static int create_hitcount_val(struct hist_trigger_data *hist_data) { hist_data->fields[HITCOUNT_IDX] = - create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT); + create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL); if (!hist_data->fields[HITCOUNT_IDX]) return -ENOMEM; hist_data->n_vals++; + hist_data->n_fields++; if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX)) return -EINVAL; @@ -524,19 +620,16 @@ static int create_hitcount_val(struct hist_trigger_data *hist_data) return 0; } -static int create_val_field(struct hist_trigger_data *hist_data, - unsigned int val_idx, - struct trace_event_file *file, - char *field_str) +static int __create_val_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *var_name, char *field_str, + unsigned long flags) { struct ftrace_event_field *field = NULL; - unsigned long flags = 0; char *field_name; int ret = 0; - if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX)) - return -EINVAL; - field_name = strsep(&field_str, "."); if (field_str) { if (strcmp(field_str, "hex") == 0) @@ -558,25 +651,58 @@ static int create_val_field(struct hist_trigger_data *hist_data, } } - hist_data->fields[val_idx] = create_hist_field(hist_data, field, flags); + hist_data->fields[val_idx] = create_hist_field(hist_data, field, flags, var_name); if (!hist_data->fields[val_idx]) { ret = -ENOMEM; goto out; } ++hist_data->n_vals; + ++hist_data->n_fields; - if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX)) + if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX)) ret = -EINVAL; out: return ret; } +static int create_val_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *field_str) +{ + if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX)) + return -EINVAL; + + return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0); +} + +static int create_var_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *var_name, char *expr_str) +{ + unsigned long flags = 0; + + if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX)) + return -EINVAL; + if (find_var(hist_data, file, var_name) && !hist_data->remove) { + return -EINVAL; + } + + flags |= HIST_FIELD_FL_VAR; + hist_data->n_vars++; + if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX)) + return -EINVAL; + + return __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags); +} + static int create_val_fields(struct hist_trigger_data *hist_data, struct trace_event_file *file) { char *fields_str, *field_str; - unsigned int i, j; + unsigned int i, j = 1; int ret; ret = create_hitcount_val(hist_data); @@ -596,12 +722,15 @@ static int create_val_fields(struct hist_trigger_data *hist_data, field_str = strsep(&fields_str, ","); if (!field_str) break; + if (strcmp(field_str, "hitcount") == 0) continue; + ret = create_val_field(hist_data, j++, file, field_str); if (ret) goto out; } + if (fields_str && (strcmp(fields_str, "hitcount") != 0)) ret = -EINVAL; out: @@ -615,11 +744,12 @@ static int create_key_field(struct hist_trigger_data *hist_data, char *field_str) { struct ftrace_event_field *field = NULL; + struct hist_field *hist_field = NULL; unsigned long flags = 0; unsigned int key_size; int ret = 0; - if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX)) + if (WARN_ON(key_idx >= HIST_FIELDS_MAX)) return -EINVAL; flags |= HIST_FIELD_FL_KEY; @@ -627,6 +757,7 @@ static int create_key_field(struct hist_trigger_data *hist_data, if (strcmp(field_str, "stacktrace") == 0) { flags |= HIST_FIELD_FL_STACKTRACE; key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH; + hist_field = create_hist_field(hist_data, NULL, flags, NULL); } else { char *field_name = strsep(&field_str, "."); @@ -672,7 +803,7 @@ static int create_key_field(struct hist_trigger_data *hist_data, } } - hist_data->fields[key_idx] = create_hist_field(hist_data, field, flags); + hist_data->fields[key_idx] = create_hist_field(hist_data, field, flags, NULL); if (!hist_data->fields[key_idx]) { ret = -ENOMEM; goto out; @@ -688,6 +819,7 @@ static int create_key_field(struct hist_trigger_data *hist_data, } hist_data->n_keys++; + hist_data->n_fields++; if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX)) return -EINVAL; @@ -731,21 +863,111 @@ static int create_key_fields(struct hist_trigger_data *hist_data, return ret; } +static int create_var_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + unsigned int i, j = hist_data->n_vals; + int ret = 0; + + unsigned int n_vars = hist_data->attrs->var_defs.n_vars; + + for (i = 0; i < n_vars; i++) { + char *var_name = hist_data->attrs->var_defs.name[i]; + char *expr = hist_data->attrs->var_defs.expr[i]; + + ret = create_var_field(hist_data, j++, file, var_name, expr); + if (ret) + goto out; + } + out: + return ret; +} + +static void free_var_defs(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) { + kfree(hist_data->attrs->var_defs.name[i]); + kfree(hist_data->attrs->var_defs.expr[i]); + } + + hist_data->attrs->var_defs.n_vars = 0; +} + +static int parse_var_defs(struct hist_trigger_data *hist_data) +{ + char *s, *str, *var_name, *field_str; + unsigned int i, j, n_vars = 0; + int ret = 0; + + for (i = 0; i < hist_data->attrs->n_assignments; i++) { + str = hist_data->attrs->assignment_str[i]; + for (j = 0; j < TRACING_MAP_VARS_MAX; j++) { + field_str = strsep(&str, ","); + if (!field_str) + break; + + var_name = strsep(&field_str, "="); + if (!var_name || !field_str) { + ret = -EINVAL; + goto free; + } + + if (n_vars == TRACING_MAP_VARS_MAX) { + ret = -EINVAL; + goto free; + } + + s = kstrdup(var_name, GFP_KERNEL); + if (!s) { + ret = -ENOMEM; + goto free; + } + hist_data->attrs->var_defs.name[n_vars] = s; + + s = kstrdup(field_str, GFP_KERNEL); + if (!s) { + kfree(hist_data->attrs->var_defs.name[n_vars]); + ret = -ENOMEM; + goto free; + } + hist_data->attrs->var_defs.expr[n_vars++] = s; + + hist_data->attrs->var_defs.n_vars = n_vars; + } + } + + return ret; + free: + free_var_defs(hist_data); + + return ret; +} + static int create_hist_fields(struct hist_trigger_data *hist_data, struct trace_event_file *file) { int ret; + ret = parse_var_defs(hist_data); + if (ret) + goto out; + ret = create_val_fields(hist_data, file); if (ret) goto out; + ret = create_var_fields(hist_data, file); + if (ret) + goto out; + ret = create_key_fields(hist_data, file); if (ret) goto out; - - hist_data->n_fields = hist_data->n_vals + hist_data->n_keys; out: + free_var_defs(hist_data); + return ret; } @@ -768,7 +990,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data) char *fields_str = hist_data->attrs->sort_key_str; struct tracing_map_sort_key *sort_key; int descending, ret = 0; - unsigned int i, j; + unsigned int i, j, k; hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */ @@ -816,12 +1038,19 @@ static int create_sort_keys(struct hist_trigger_data *hist_data) continue; } - for (j = 1; j < hist_data->n_fields; j++) { + for (j = 1, k = 1; j < hist_data->n_fields; j++) { + unsigned int idx; + hist_field = hist_data->fields[j]; + if (hist_field->flags & HIST_FIELD_FL_VAR) + continue; + + idx = k++; + test_name = hist_field_name(hist_field, 0); if (strcmp(field_name, test_name) == 0) { - sort_key->field_idx = j; + sort_key->field_idx = idx; descending = is_descending(field_str); if (descending < 0) { ret = descending; @@ -836,6 +1065,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data) break; } } + hist_data->n_sort_keys = i; out: return ret; @@ -876,12 +1106,19 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) idx = tracing_map_add_key_field(map, hist_field->offset, cmp_fn); - - } else + } else if (!(hist_field->flags & HIST_FIELD_FL_VAR)) idx = tracing_map_add_sum_field(map); if (idx < 0) return idx; + + if (hist_field->flags & HIST_FIELD_FL_VAR) { + idx = tracing_map_add_var(map); + if (idx < 0) + return idx; + hist_field->var.idx = idx; + hist_field->var.hist_data = hist_data; + } } return 0; @@ -905,7 +1142,8 @@ static bool need_tracing_map_ops(struct hist_trigger_data *hist_data) static struct hist_trigger_data * create_hist_data(unsigned int map_bits, struct hist_trigger_attrs *attrs, - struct trace_event_file *file) + struct trace_event_file *file, + bool remove) { const struct tracing_map_ops *map_ops = NULL; struct hist_trigger_data *hist_data; @@ -916,6 +1154,7 @@ create_hist_data(unsigned int map_bits, return ERR_PTR(-ENOMEM); hist_data->attrs = attrs; + hist_data->remove = remove; ret = create_hist_fields(hist_data, file); if (ret) @@ -962,14 +1201,28 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, struct ring_buffer_event *rbe) { struct hist_field *hist_field; - unsigned int i; + unsigned int i, var_idx; u64 hist_val; for_each_hist_val_field(i, hist_data) { hist_field = hist_data->fields[i]; hist_val = hist_field->fn(hist_field, rec, rbe); + if (hist_field->flags & HIST_FIELD_FL_VAR) { + var_idx = hist_field->var.idx; + tracing_map_set_var(elt, var_idx, hist_val); + continue; + } tracing_map_update_sum(elt, i, hist_val); } + + for_each_hist_key_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (hist_field->flags & HIST_FIELD_FL_VAR) { + hist_val = hist_field->fn(hist_field, rec, rbe); + var_idx = hist_field->var.idx; + tracing_map_set_var(elt, var_idx, hist_val); + } + } } static inline void add_to_key(char *compound_key, void *key, @@ -1144,6 +1397,9 @@ hist_trigger_entry_print(struct seq_file *m, for (i = 1; i < hist_data->n_vals; i++) { field_name = hist_field_name(hist_data->fields[i], 0); + if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR) + continue; + if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) { seq_printf(m, " %s: %10llx", field_name, tracing_map_read_sum(elt, i)); @@ -1265,6 +1521,9 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) { const char *field_name = hist_field_name(hist_field, 0); + if (hist_field->var.name) + seq_printf(m, "%s=", hist_field->var.name); + if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP) seq_puts(m, "common_timestamp"); else if (field_name) @@ -1283,7 +1542,8 @@ static int event_hist_trigger_print(struct seq_file *m, struct event_trigger_data *data) { struct hist_trigger_data *hist_data = data->private_data; - struct hist_field *key_field; + struct hist_field *field; + bool have_var = false; unsigned int i; seq_puts(m, "hist:"); @@ -1294,25 +1554,47 @@ static int event_hist_trigger_print(struct seq_file *m, seq_puts(m, "keys="); for_each_hist_key_field(i, hist_data) { - key_field = hist_data->fields[i]; + field = hist_data->fields[i]; if (i > hist_data->n_vals) seq_puts(m, ","); - if (key_field->flags & HIST_FIELD_FL_STACKTRACE) + if (field->flags & HIST_FIELD_FL_STACKTRACE) seq_puts(m, "stacktrace"); else - hist_field_print(m, key_field); + hist_field_print(m, field); } seq_puts(m, ":vals="); for_each_hist_val_field(i, hist_data) { + field = hist_data->fields[i]; + if (field->flags & HIST_FIELD_FL_VAR) { + have_var = true; + continue; + } + if (i == HITCOUNT_IDX) seq_puts(m, "hitcount"); else { seq_puts(m, ","); - hist_field_print(m, hist_data->fields[i]); + hist_field_print(m, field); + } + } + + if (have_var) { + unsigned int n = 0; + + seq_puts(m, ":"); + + for_each_hist_val_field(i, hist_data) { + field = hist_data->fields[i]; + + if (field->flags & HIST_FIELD_FL_VAR) { + if (n++) + seq_puts(m, ","); + hist_field_print(m, field); + } } } @@ -1320,7 +1602,10 @@ static int event_hist_trigger_print(struct seq_file *m, for (i = 0; i < hist_data->n_sort_keys; i++) { struct tracing_map_sort_key *sort_key; - unsigned int idx; + unsigned int idx, first_key_idx; + + /* skip VAR vals */ + first_key_idx = hist_data->n_vals - hist_data->n_vars; sort_key = &hist_data->sort_keys[i]; idx = sort_key->field_idx; @@ -1333,8 +1618,11 @@ static int event_hist_trigger_print(struct seq_file *m, if (idx == HITCOUNT_IDX) seq_puts(m, "hitcount"); - else + else { + if (idx >= first_key_idx) + idx += hist_data->n_vars; hist_field_print(m, hist_data->fields[idx]); + } if (sort_key->descending) seq_puts(m, ".descending"); @@ -1631,7 +1919,7 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops, test->ops->free(test->ops, test); if (hist_data->enable_timestamps) { - if (unregistered) + if (!hist_data->remove || unregistered) tracing_set_time_stamp_abs(file->tr, false); } } @@ -1664,12 +1952,16 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, struct hist_trigger_attrs *attrs; struct event_trigger_ops *trigger_ops; struct hist_trigger_data *hist_data; + bool remove = false; char *trigger; int ret = 0; if (!param) return -EINVAL; + if (glob[0] == '!') + remove = true; + /* separate the trigger from the filter (k:v [if filter]) */ trigger = strsep(¶m, " \t"); if (!trigger) @@ -1682,7 +1974,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, if (attrs->map_bits) hist_trigger_bits = attrs->map_bits; - hist_data = create_hist_data(hist_trigger_bits, attrs, file); + hist_data = create_hist_data(hist_trigger_bits, attrs, file, remove); if (IS_ERR(hist_data)) { destroy_hist_trigger_attrs(attrs); return PTR_ERR(hist_data); @@ -1711,7 +2003,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, goto out_free; } - if (glob[0] == '!') { + if (remove) { cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); ret = 0; goto out_free;