On Mon, 1 Oct 2018 16:59:17 +0300
Yordan Karadzhov <ykaradzhov@xxxxxxxxxx> wrote:
> From: "Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx>
>
> The kshark_get_X_easy() functions allow for an easy access to the
> tep_record's fields. Using these functions can be inefficient if you
> need access to more than one of the fields of the record.
>
> Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@xxxxxxxxx>
> ---
> kernel-shark-qt/src/libkshark.c | 185 ++++++++++++++++++++++++++++++++
> kernel-shark-qt/src/libkshark.h | 12 +++
> 2 files changed, 197 insertions(+)
>
> diff --git a/kernel-shark-qt/src/libkshark.c b/kernel-shark-qt/src/libkshark.c
> index 506511d..a7983eb 100644
> --- a/kernel-shark-qt/src/libkshark.c
> +++ b/kernel-shark-qt/src/libkshark.c
> @@ -888,6 +888,191 @@ static const char *kshark_get_info(struct tep_handle *pe,
> return seq.buffer;
> }
>
> +/**
> + * @brief This function allows for an easy access to the original value of the
> + * Process Id as recorded in the tep_record object. The record is read
> + * from the file only in the case of an entry being touched by a plugin.
> + * Be aware that using the kshark_get_X_easy functions can be
> + * inefficient if you need an access to more than one of the data fields
> + * of the record.
> + *
> + * @param entry: Input location for the KernelShark entry.
> + *
> + * @returns The original value of the Process Id as recorded in the
> + * tep_record object on success, otherwise negative error code.
> + */
> +int kshark_get_pid_easy(struct kshark_entry *entry)
> +{
> + struct kshark_context *kshark_ctx = NULL;
> + struct tep_record *data;
> + int pid;
> +
> + if (!kshark_instance(&kshark_ctx))
> + return -EFAULT;
Perhaps this should return -ENODEV;
> +
> + if (entry->visible & KS_PLUGIN_UNTOUCHED_MASK) {
What's the "UNTOUCHED_MASK" mean?
> + pid = entry->pid;
> + } else {
> + data = kshark_read_at(kshark_ctx, entry->offset);
> + pid = tep_data_pid(kshark_ctx->pevent, data);
> + free_record(data);
Would it be possible to do:
entry->visible |= KS_PLUGIN_UNTOUCHED_MASK;
entry->pid = pid;
?
Of course this depends on what that mask means.
> + }
> +
> + return pid;
> +}
> +
> +/**
> + * @brief This function allows for an easy access to the original value of the
> + * Task name as recorded in the tep_record object. The record is read
> + * from the file only in the case of an entry being touched by a plugin.
> + * Be aware that using the kshark_get_X_easy functions can be
> + * inefficient if you need an access to more than one of the data fields
> + * of the record.
> + *
> + * @param entry: Input location for the KernelShark entry.
> + *
> + * @returns The original name of the task, retrieved from the Process Id
> + * recorded in the tep_record object on success, otherwise NULL.
> + */
> +const char *kshark_get_task_easy(struct kshark_entry *entry)
> +{
> + struct kshark_context *kshark_ctx = NULL;
> + int pid = kshark_get_pid_easy(entry);
> +
> + if (pid < 0 || !kshark_instance(&kshark_ctx))
The second part is redundant, as kshark_get_pid_easy() will return
pid < 0 if that was true.
> + return NULL;
> +
> + return tep_data_comm_from_pid(kshark_ctx->pevent, pid);
> +}
> +
> +/**
> + * @brief This function allows for an easy access to the latency information
> + * recorded in the tep_record object. The record is read from the file
> + * using the offset field of kshark_entry. Be aware that using the
> + * kshark_get_X_easy functions can be inefficient if you need an access
> + * to more than one of the data fields of the record.
> + *
> + * @param entry: Input location for the KernelShark entry.
> + *
> + * @returns On success the function returns a string showing the latency
> + * information, coded into 5 fields:
> + * interrupts disabled, need rescheduling, hard/soft interrupt,
> + * preempt count and lock depth. On failure it returns NULL.
> + */
> +const char *kshark_get_latency_easy(struct kshark_entry *entry)
> +{
> + struct kshark_context *kshark_ctx = NULL;
> + struct tep_record *data;
> + const char *lat;
> +
> + if (!kshark_instance(&kshark_ctx))
> + return NULL;
> +
> + data = kshark_read_at(kshark_ctx, entry->offset);
> + lat = kshark_get_latency(kshark_ctx->pevent, data);
> + free_record(data);
> +
> + return lat;
> +}
> +
> +/**
> + * @brief This function allows for an easy access to the original value of the
> + * Event Id as recorded in the tep_record object. The record is read
> + * from the file only in the case of an entry being touched by a plugin.
> + * Be aware that using the kshark_get_X_easy functions can be
> + * inefficient if you need an access to more than one of the data fields
> + * of the record.
> + *
> + * @param entry: Input location for the KernelShark entry.
> + *
> + * @returns The original value of the Event Id as recorded in the
> + * tep_record object on success, otherwise negative error code.
> + */
> +int kshark_get_event_id_easy(struct kshark_entry *entry)
> +{
> + struct kshark_context *kshark_ctx = NULL;
> + struct tep_record *data;
> + int event_id;
> +
> + if (!kshark_instance(&kshark_ctx))
> + return -EFAULT;
> +
> + if (entry->visible & KS_PLUGIN_UNTOUCHED_MASK) {
> + event_id = entry->event_id;
> + } else {
> + data = kshark_read_at(kshark_ctx, entry->offset);
> + event_id = tep_data_type(kshark_ctx->pevent, data);
> + free_record(data);
If the above can update "easy" untouch flag, then this too.
> + }
> +
> + return event_id;
> +}
> +
> +/**
> + * @brief This function allows for an easy access to the original name of the
> + * trace event as recorded in the tep_record object. The record is read
> + * from the file only in the case of an entry being touched by a plugin.
> + * Be aware that using the kshark_get_X_easy functions can be
> + * inefficient if you need an access to more than one of the data fields
> + * of the record.
> + *
> + * @param entry: Input location for the KernelShark entry.
> + *
> + * @returns The mane of the trace event recorded in the tep_record object on
> + * success, otherwise "[UNKNOWN EVENT]" or NULL.
> + */
> +const char *kshark_get_event_name_easy(struct kshark_entry *entry)
> +{
> + struct kshark_context *kshark_ctx = NULL;
> + struct event_format *event;
> +
> + int event_id = kshark_get_event_id_easy(entry);
> +
> + if (event_id < 0 || !kshark_instance(&kshark_ctx))
Again this is redundant.
-- Steve
> + return NULL;
> +
> + event = tep_data_event_from_type(kshark_ctx->pevent, event_id);
> + if (event)
> + return event->name;
> +
> + return "[UNKNOWN EVENT]";
> +}
> +
> +/**
> + * @brief This function allows for an easy access to the tep_record's info
> + * streang. The record is read from the file using the offset field of
> + * kshark_entry. Be aware that using the kshark_get_X_easy functions can
> + * be inefficient if you need an access to more than one of the data
> + * fields of the record.
> + *
> + * @param entry: Input location for the KernelShark entry.
> + *
> + * @returns A string showing the data output of the trace event on success,
> + * otherwise NULL.
> + */
> +const char *kshark_get_info_easy(struct kshark_entry *entry)
> +{
> + struct kshark_context *kshark_ctx = NULL;
> + struct event_format *event;
> + struct tep_record *data;
> + const char *info = NULL;
> + int event_id;
> +
> + if (!kshark_instance(&kshark_ctx))
> + return NULL;
> +
> + data = kshark_read_at(kshark_ctx, entry->offset);
> +
> + event_id = tep_data_type(kshark_ctx->pevent, data);
> + event = tep_data_event_from_type(kshark_ctx->pevent, event_id);
> + if (event)
> + info = kshark_get_info(kshark_ctx->pevent, data, event);
> +
> + free_record(data);
> +
> + return info;
> +}
> +
> /**
> * @brief Dump into a string the content of one entry. The function allocates
> * a null terminated string and returns a pointer to this string. The
> diff --git a/kernel-shark-qt/src/libkshark.h b/kernel-shark-qt/src/libkshark.h
> index e846c85..f00a584 100644
> --- a/kernel-shark-qt/src/libkshark.h
> +++ b/kernel-shark-qt/src/libkshark.h
> @@ -148,6 +148,18 @@ void kshark_close(struct kshark_context *kshark_ctx);
>
> void kshark_free(struct kshark_context *kshark_ctx);
>
> +int kshark_get_pid_easy(struct kshark_entry *entry);
> +
> +const char *kshark_get_task_easy(struct kshark_entry *entry);
> +
> +const char *kshark_get_latency_easy(struct kshark_entry *entry);
> +
> +int kshark_get_event_id_easy(struct kshark_entry *entry);
> +
> +const char *kshark_get_event_name_easy(struct kshark_entry *entry);
> +
> +const char *kshark_get_info_easy(struct kshark_entry *entry);
> +
> char* kshark_dump_entry(const struct kshark_entry *entry);
>
> struct tep_record *kshark_read_at(struct kshark_context *kshark_ctx,
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