From 8e254c1d183f0225ad21f9049641529e56cce4da Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 31 Aug 2009 16:49:41 +0800 Subject: tracing/filters: Defer pred allocation init_preds() allocates about 5392 bytes of memory (on x86_32) for a TRACE_EVENT. With my config, at system boot total memory occupied is: 5392 * (642 + 15) == 3459KB 642 == cat available_events | wc -l 15 == number of dirs in events/ftrace That's quite a lot, so we'd better defer memory allocation util it's needed, that's when filter is used. Signed-off-by: Li Zefan Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Tom Zanussi Cc: Masami Hiramatsu LKML-Reference: <4A9B8EA5.6020700@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_events_filter.c | 50 +++++++++++++++++++++++++++++++------- kernel/trace/trace_export.c | 1 - 2 files changed, 41 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 9f03082c81d8..c6b2edfb7fe9 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -309,7 +309,7 @@ void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s) struct event_filter *filter = call->filter; mutex_lock(&event_mutex); - if (filter->filter_string) + if (filter && filter->filter_string) trace_seq_printf(s, "%s\n", filter->filter_string); else trace_seq_printf(s, "none\n"); @@ -322,7 +322,7 @@ void print_subsystem_event_filter(struct event_subsystem *system, struct event_filter *filter = system->filter; mutex_lock(&event_mutex); - if (filter->filter_string) + if (filter && filter->filter_string) trace_seq_printf(s, "%s\n", filter->filter_string); else trace_seq_printf(s, "none\n"); @@ -390,6 +390,9 @@ void destroy_preds(struct ftrace_event_call *call) struct event_filter *filter = call->filter; int i; + if (!filter) + return; + for (i = 0; i < MAX_FILTER_PRED; i++) { if (filter->preds[i]) filter_free_pred(filter->preds[i]); @@ -400,7 +403,7 @@ void destroy_preds(struct ftrace_event_call *call) call->filter = NULL; } -int init_preds(struct ftrace_event_call *call) +static int init_preds(struct ftrace_event_call *call) { struct event_filter *filter; struct filter_pred *pred; @@ -410,7 +413,6 @@ int init_preds(struct ftrace_event_call *call) if (!call->filter) return -ENOMEM; - call->filter_active = 0; filter->n_preds = 0; filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL); @@ -432,7 +434,28 @@ oom: return -ENOMEM; } -EXPORT_SYMBOL_GPL(init_preds); + +static int init_subsystem_preds(struct event_subsystem *system) +{ + struct ftrace_event_call *call; + int err; + + list_for_each_entry(call, &ftrace_events, list) { + if (!call->define_fields) + continue; + + if (strcmp(call->system, system->name) != 0) + continue; + + if (!call->filter) { + err = init_preds(call); + if (err) + return err; + } + } + + return 0; +} enum { FILTER_DISABLE_ALL, @@ -449,6 +472,9 @@ static void filter_free_subsystem_preds(struct event_subsystem *system, if (!call->define_fields) continue; + if (strcmp(call->system, system->name) != 0) + continue; + if (flag == FILTER_INIT_NO_RESET) { call->filter->no_reset = false; continue; @@ -457,10 +483,8 @@ static void filter_free_subsystem_preds(struct event_subsystem *system, if (flag == FILTER_SKIP_NO_RESET && call->filter->no_reset) continue; - if (!strcmp(call->system, system->name)) { - filter_disable_preds(call); - remove_filter_string(call->filter); - } + filter_disable_preds(call); + remove_filter_string(call->filter); } } @@ -1094,6 +1118,10 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string) mutex_lock(&event_mutex); + err = init_preds(call); + if (err) + goto out_unlock; + if (!strcmp(strstrip(filter_string), "0")) { filter_disable_preds(call); remove_filter_string(call->filter); @@ -1139,6 +1167,10 @@ int apply_subsystem_event_filter(struct event_subsystem *system, mutex_lock(&event_mutex); + err = init_subsystem_preds(system); + if (err) + goto out_unlock; + if (!strcmp(strstrip(filter_string), "0")) { filter_free_subsystem_preds(system, FILTER_DISABLE_ALL); remove_filter_string(system->filter); diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 029a91f42287..df1bf6e48bb9 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -135,7 +135,6 @@ __attribute__((section("_ftrace_events"))) event_##call = { \ static int ftrace_raw_init_event_##call(void) \ { \ INIT_LIST_HEAD(&event_##call.fields); \ - init_preds(&event_##call); \ return 0; \ } \ -- cgit