[ltt-dev] [PATCH 2/2] Make ltt support enable/disable each channel
Zhaolei
zhaolei at cn.fujitsu.com
Tue Dec 2 06:22:31 EST 2008
It can reduce system loads when user only need to trace some
channels.
Signed-off-by: Zhao Lei <zhaolei at cn.fujitsu.com>
---
include/linux/ltt-tracer.h | 2 +
ltt/ltt-serialize.c | 4 +
ltt/ltt-tracer.c | 268 +++++++++++++++++++++++++-------------
ltt/probes/ltt-type-serializer.c | 4 +
4 files changed, 190 insertions(+), 88 deletions(-)
diff --git a/include/linux/ltt-tracer.h b/include/linux/ltt-tracer.h
index a18edd1..87696a9 100644
--- a/include/linux/ltt-tracer.h
+++ b/include/linux/ltt-tracer.h
@@ -711,6 +711,8 @@ int ltt_trace_set_channel_subbufsize(const char *trace_name,
const char *channel_name, unsigned size);
int ltt_trace_set_channel_subbufcount(const char *trace_name,
const char *channel_name, unsigned cnt);
+int ltt_trace_set_channel_enable(const char *trace_name,
+ const char *channel_name, unsigned enable);
int ltt_trace_set_channel_overwrite(const char *trace_name,
const char *channel_name, unsigned overwrite);
int ltt_trace_alloc(const char *trace_name);
diff --git a/ltt/ltt-serialize.c b/ltt/ltt-serialize.c
index 3b31a30..9d7ce59 100644
--- a/ltt/ltt-serialize.c
+++ b/ltt/ltt-serialize.c
@@ -633,6 +633,10 @@ notrace void ltt_vtrace(void *probe_data, void *call_data,
rflags = 0;
#endif
channel = ltt_get_channel_from_index(trace, channel_index);
+ if (!channel)
+ /* channel is NULL if it is not enabled */
+ continue;
+
/* reserve space : header and data */
ret = ltt_reserve_slot(trace, channel, &transport_data,
data_size, &slot_size, &buf_offset,
diff --git a/ltt/ltt-tracer.c b/ltt/ltt-tracer.c
index 341074d..a14fd5f 100644
--- a/ltt/ltt-tracer.c
+++ b/ltt/ltt-tracer.c
@@ -67,6 +67,69 @@ int (*ltt_statedump_functor)(struct ltt_trace_struct *trace) =
ltt_statedump_default;
struct module *ltt_statedump_owner;
+/*
+ * Todo:
+ * Make similar function in channel.c,
+ * so it will be useful for both ltt-tracer.c and ltt-marker-control.c
+ */
+/*
+ * Its order is MUST be same with enum ltt_channels
+ */
+struct chan_info_struct {
+ const char *name;
+ unsigned int channel_index;
+ unsigned int def_subbufsize;
+ unsigned int def_subbufcount;
+} chan_infos[] = {
+ [LTT_CHANNEL_CPU] = {
+ LTT_CPU_CHANNEL,
+ GET_CHANNEL_INDEX(cpu),
+ LTT_DEFAULT_SUBBUF_SIZE_HIGH,
+ LTT_DEFAULT_N_SUBBUFS_HIGH,
+ },
+ [LTT_CHANNEL_PROCESSES] = {
+ LTT_PROCESSES_CHANNEL,
+ GET_CHANNEL_INDEX(processes),
+ LTT_DEFAULT_SUBBUF_SIZE_MED,
+ LTT_DEFAULT_N_SUBBUFS_MED,
+ },
+ [LTT_CHANNEL_INTERRUPTS] = {
+ LTT_INTERRUPTS_CHANNEL,
+ GET_CHANNEL_INDEX(interrupts),
+ LTT_DEFAULT_SUBBUF_SIZE_LOW,
+ LTT_DEFAULT_N_SUBBUFS_LOW,
+ },
+ [LTT_CHANNEL_NETWORK] = {
+ LTT_NETWORK_CHANNEL,
+ GET_CHANNEL_INDEX(network),
+ LTT_DEFAULT_SUBBUF_SIZE_LOW,
+ LTT_DEFAULT_N_SUBBUFS_LOW,
+ },
+ [LTT_CHANNEL_MODULES] = {
+ LTT_MODULES_CHANNEL,
+ GET_CHANNEL_INDEX(modules),
+ LTT_DEFAULT_SUBBUF_SIZE_LOW,
+ LTT_DEFAULT_N_SUBBUFS_LOW,
+ },
+ [LTT_CHANNEL_METADATA] = {
+ LTT_METADATA_CHANNEL,
+ GET_CHANNEL_INDEX(metadata),
+ LTT_DEFAULT_SUBBUF_SIZE_LOW,
+ LTT_DEFAULT_N_SUBBUFS_LOW,
+ },
+};
+
+static enum ltt_channels get_channel_type_from_name(const char *name)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(chan_infos); i++)
+ if (!strcmp(name, chan_infos[i].name))
+ return (enum ltt_channels)i;
+
+ return NR_LTT_CHANNELS;
+}
+
/**
* ltt_module_register : LTT module registration
* @name : module type
@@ -216,13 +279,17 @@ EXPORT_SYMBOL_GPL(ltt_write_trace_header);
static void trace_async_wakeup(struct ltt_trace_struct *trace)
{
+ int i;
+ struct ltt_channel_struct *chan;
+
/* Must check each channel for pending read wakeup */
- trace->ops->wakeup_channel(trace->channel.metadata);
- trace->ops->wakeup_channel(trace->channel.interrupts);
- trace->ops->wakeup_channel(trace->channel.processes);
- trace->ops->wakeup_channel(trace->channel.modules);
- trace->ops->wakeup_channel(trace->channel.network);
- trace->ops->wakeup_channel(trace->channel.cpu);
+ for (i = 0; i < NR_LTT_CHANNELS; i++) {
+ chan = *(struct ltt_channel_struct **)((char *)trace
+ + chan_infos[i].channel_index);
+ /* chan is NULL if it is not traced */
+ if (chan)
+ trace->ops->wakeup_channel(chan);
+ }
}
/* Timer to send async wakeups to the readers */
@@ -355,6 +422,14 @@ int ltt_trace_setup(const char *trace_name)
}
strncpy(new_trace->trace_name, trace_name, NAME_MAX);
+
+ /*
+ * Datas in metadata channel(marker info) is necessary to be able to
+ * read the trace, it is enabled initially, and can't be disabled later.
+ */
+ new_trace->setting.channels[LTT_CHANNEL_METADATA].flags |=
+ CHANNEL_FLAG_ENABLE;
+
list_add(&new_trace->list, <t_traces.setup_head);
ltt_unlock_traces();
@@ -412,69 +487,6 @@ traces_error:
}
EXPORT_SYMBOL_GPL(ltt_trace_set_type);
-/*
- * Todo:
- * Make similar function in channel.c,
- * so it will be useful for both ltt-tracer.c and ltt-marker-control.c
- */
-/*
- * Its order is MUST be same with enum ltt_channels
- */
-struct chan_info_struct {
- const char *name;
- unsigned int channel_index;
- unsigned int def_subbufsize;
- unsigned int def_subbufcount;
-} chan_infos[] = {
- [LTT_CHANNEL_CPU] = {
- LTT_CPU_CHANNEL,
- GET_CHANNEL_INDEX(cpu),
- LTT_DEFAULT_SUBBUF_SIZE_HIGH,
- LTT_DEFAULT_N_SUBBUFS_HIGH,
- },
- [LTT_CHANNEL_PROCESSES] = {
- LTT_PROCESSES_CHANNEL,
- GET_CHANNEL_INDEX(processes),
- LTT_DEFAULT_SUBBUF_SIZE_MED,
- LTT_DEFAULT_N_SUBBUFS_MED,
- },
- [LTT_CHANNEL_INTERRUPTS] = {
- LTT_INTERRUPTS_CHANNEL,
- GET_CHANNEL_INDEX(interrupts),
- LTT_DEFAULT_SUBBUF_SIZE_LOW,
- LTT_DEFAULT_N_SUBBUFS_LOW,
- },
- [LTT_CHANNEL_NETWORK] = {
- LTT_NETWORK_CHANNEL,
- GET_CHANNEL_INDEX(network),
- LTT_DEFAULT_SUBBUF_SIZE_LOW,
- LTT_DEFAULT_N_SUBBUFS_LOW,
- },
- [LTT_CHANNEL_MODULES] = {
- LTT_MODULES_CHANNEL,
- GET_CHANNEL_INDEX(modules),
- LTT_DEFAULT_SUBBUF_SIZE_LOW,
- LTT_DEFAULT_N_SUBBUFS_LOW,
- },
- [LTT_CHANNEL_METADATA] = {
- LTT_METADATA_CHANNEL,
- GET_CHANNEL_INDEX(metadata),
- LTT_DEFAULT_SUBBUF_SIZE_LOW,
- LTT_DEFAULT_N_SUBBUFS_LOW,
- },
-};
-
-static enum ltt_channels get_channel_type_from_name(const char *name)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(chan_infos); i++)
- if (!strcmp(name, chan_infos[i].name))
- return (enum ltt_channels)i;
-
- return NR_LTT_CHANNELS;
-}
-
int ltt_trace_set_channel_subbufsize(const char *trace_name,
const char *channel_name, unsigned size)
{
@@ -539,6 +551,52 @@ traces_error:
}
EXPORT_SYMBOL_GPL(ltt_trace_set_channel_subbufcount);
+int ltt_trace_set_channel_enable(const char *trace_name,
+ const char *channel_name, unsigned enable)
+{
+ int err = 0;
+ struct ltt_trace_struct *trace;
+ enum ltt_channels channel;
+
+ ltt_lock_traces();
+
+ trace = _ltt_trace_find_setup(trace_name);
+ if (!trace) {
+ printk(KERN_ERR "LTT : Trace not found %s\n", trace_name);
+ err = -ENOENT;
+ goto traces_error;
+ }
+
+ channel = get_channel_type_from_name(channel_name);
+ if (channel == NR_LTT_CHANNELS) {
+ printk(KERN_ERR "LTT : Channel %s is not present.\n",
+ channel_name);
+ err = -EINVAL;
+ goto traces_error;
+ }
+
+ /*
+ * Datas in metadata channel(marker info) is necessary to be able to
+ * read the trace, we always enable this channel.
+ */
+ if (!enable && channel == LTT_CHANNEL_METADATA) {
+ err = -EINVAL;
+ goto traces_error;
+ }
+
+ if (enable)
+ trace->setting.channels[channel].flags |=
+ CHANNEL_FLAG_ENABLE;
+ else
+ trace->setting.channels[channel].flags &=
+ ~CHANNEL_FLAG_ENABLE;
+
+traces_error:
+ ltt_unlock_traces();
+ return err;
+}
+EXPORT_SYMBOL_GPL(ltt_trace_set_channel_enable);
+
int ltt_trace_set_channel_overwrite(const char *trace_name,
const char *channel_name, unsigned overwrite)
{
@@ -563,6 +621,12 @@ int ltt_trace_set_channel_overwrite(const char *trace_name,
goto traces_error;
}
+ /*
+ * Always put the metadata channel in non-overwrite mode :
+ * This is a very low traffic channel and it can't afford to have its
+ * data overwritten : this data (marker info) is necessary to be
+ * able to read the trace.
+ */
if (overwrite && channel == LTT_CHANNEL_METADATA) {
err = -EINVAL;
goto traces_error;
@@ -635,14 +699,11 @@ int ltt_trace_alloc(const char *trace_name)
* Config each channel's default buffersize/cnt, instead of
* LTT_DEFAULT_SUBBUF_SIZE_LOW, ...
*/
-
- /*
- * Always put the metadata channel in non-overwrite mode :
- * This is a very low traffic channel and it can't afford to have its
- * data overwritten : this data (marker info) is necessary to be
- * able to read the trace.
- */
for (chan = 0; chan < NR_LTT_CHANNELS; chan++) {
+ if (!(trace->setting.channels[chan].flags
+ & CHANNEL_FLAG_ENABLE))
+ continue;
+
subbuf_size = trace->setting.channels[chan].subbuf_size;
subbuf_cnt = trace->setting.channels[chan].subbuf_cnt;
prepare_chan_size_num(&subbuf_size, &subbuf_cnt,
@@ -724,6 +785,10 @@ static int ltt_trace_create(const char *trace_name, const char *trace_type,
if (IS_ERR_VALUE(err))
return err;
+ err = ltt_trace_set_channel_enable(trace_name, LTT_METADATA_CHANNEL, 1);
+ if (IS_ERR_VALUE(err))
+ return err;
+
err = ltt_trace_set_channel_overwrite(trace_name,
LTT_METADATA_CHANNEL,
is_channel_overwrite(LTT_CHANNEL_METADATA, mode));
@@ -740,6 +805,11 @@ static int ltt_trace_create(const char *trace_name, const char *trace_type,
if (IS_ERR_VALUE(err))
return err;
+ err = ltt_trace_set_channel_enable(trace_name, LTT_INTERRUPTS_CHANNEL,
+ 1);
+ if (IS_ERR_VALUE(err))
+ return err;
+
err = ltt_trace_set_channel_overwrite(trace_name,
LTT_INTERRUPTS_CHANNEL,
is_channel_overwrite(LTT_CHANNEL_INTERRUPTS, mode));
@@ -756,6 +826,11 @@ static int ltt_trace_create(const char *trace_name, const char *trace_type,
if (IS_ERR_VALUE(err))
return err;
+ err = ltt_trace_set_channel_enable(trace_name, LTT_PROCESSES_CHANNEL,
+ 1);
+ if (IS_ERR_VALUE(err))
+ return err;
+
err = ltt_trace_set_channel_overwrite(trace_name,
LTT_PROCESSES_CHANNEL,
is_channel_overwrite(LTT_CHANNEL_PROCESSES, mode));
@@ -772,6 +847,10 @@ static int ltt_trace_create(const char *trace_name, const char *trace_type,
if (IS_ERR_VALUE(err))
return err;
+ err = ltt_trace_set_channel_enable(trace_name, LTT_MODULES_CHANNEL, 1);
+ if (IS_ERR_VALUE(err))
+ return err;
+
err = ltt_trace_set_channel_overwrite(trace_name,
LTT_MODULES_CHANNEL,
is_channel_overwrite(LTT_CHANNEL_MODULES, mode));
@@ -788,6 +867,10 @@ static int ltt_trace_create(const char *trace_name, const char *trace_type,
if (IS_ERR_VALUE(err))
return err;
+ err = ltt_trace_set_channel_enable(trace_name, LTT_NETWORK_CHANNEL, 1);
+ if (IS_ERR_VALUE(err))
+ return err;
+
err = ltt_trace_set_channel_overwrite(trace_name,
LTT_NETWORK_CHANNEL,
is_channel_overwrite(LTT_CHANNEL_NETWORK, mode));
@@ -804,6 +887,10 @@ static int ltt_trace_create(const char *trace_name, const char *trace_type,
if (IS_ERR_VALUE(err))
return err;
+ err = ltt_trace_set_channel_enable(trace_name, LTT_CPU_CHANNEL, 1);
+ if (IS_ERR_VALUE(err))
+ return err;
+
err = ltt_trace_set_channel_overwrite(trace_name,
LTT_CPU_CHANNEL, is_channel_overwrite(LTT_CHANNEL_CPU, mode));
if (IS_ERR_VALUE(err))
@@ -855,12 +942,16 @@ traces_error:
/* Sleepable part of the destroy */
static void __ltt_trace_destroy(struct ltt_trace_struct *trace)
{
- trace->ops->finish_channel(trace->channel.metadata);
- trace->ops->finish_channel(trace->channel.interrupts);
- trace->ops->finish_channel(trace->channel.processes);
- trace->ops->finish_channel(trace->channel.modules);
- trace->ops->finish_channel(trace->channel.network);
- trace->ops->finish_channel(trace->channel.cpu);
+ int i;
+ struct ltt_channel_struct *chan;
+
+ for (i = 0; i < NR_LTT_CHANNELS; i++) {
+ chan = *(struct ltt_channel_struct **)((char *)trace
+ + chan_infos[i].channel_index);
+ /* chan is NULL if it is not traced */
+ if (chan)
+ trace->ops->finish_channel(chan);
+ }
flush_scheduled_work();
@@ -871,12 +962,13 @@ static void __ltt_trace_destroy(struct ltt_trace_struct *trace)
*/
trace_async_wakeup(trace);
- trace->ops->remove_channel(trace->channel.metadata);
- trace->ops->remove_channel(trace->channel.interrupts);
- trace->ops->remove_channel(trace->channel.processes);
- trace->ops->remove_channel(trace->channel.modules);
- trace->ops->remove_channel(trace->channel.network);
- trace->ops->remove_channel(trace->channel.cpu);
+ for (i = 0; i < NR_LTT_CHANNELS; i++) {
+ chan = *(struct ltt_channel_struct **)((char *)trace
+ + chan_infos[i].channel_index);
+ /* chan is NULL if it is not traced */
+ if (chan)
+ trace->ops->remove_channel(chan);
+ }
kref_put(&trace->ltt_transport_kref, ltt_release_transport);
diff --git a/ltt/probes/ltt-type-serializer.c b/ltt/probes/ltt-type-serializer.c
index 1f93181..317d329 100644
--- a/ltt/probes/ltt-type-serializer.c
+++ b/ltt/probes/ltt-type-serializer.c
@@ -55,6 +55,10 @@ notrace void _ltt_specialized_trace(void *probe_data,
rflags = 0;
#endif
channel = ltt_get_channel_from_index(trace, channel_index);
+ if (!channel)
+ /* channel is NULL if it is not enabled */
+ continue;
+
/* reserve space : header and data */
ret = ltt_reserve_slot(trace, channel, &transport_data,
data_size, &slot_size, &buf_offset,
--
1.5.5.3
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