On Mon, 1 Oct 2018 16:59:18 +0300
Yordan Karadzhov <ykaradzhov@xxxxxxxxxx> wrote:
> From: "Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx>
>
> kshark_convert_nano() is used to convert the original value of the
> timestamp of the trace records (having nanosecond precision) into two
> values representing the time in seconds and milliseconds.
>
> Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@xxxxxxxxx>
> ---
> kernel-shark-qt/src/libkshark.c | 14 ++++++++++++++
> kernel-shark-qt/src/libkshark.h | 2 ++
> 2 files changed, 16 insertions(+)
>
> diff --git a/kernel-shark-qt/src/libkshark.c b/kernel-shark-qt/src/libkshark.c
> index a7983eb..e7ea007 100644
> --- a/kernel-shark-qt/src/libkshark.c
> +++ b/kernel-shark-qt/src/libkshark.c
> @@ -1073,6 +1073,20 @@ const char *kshark_get_info_easy(struct kshark_entry *entry)
> return info;
> }
>
> +/**
> + * @brief Convert the timestamp of the trace record (nanosecond precision) into
> + * seconds and microseconds.
> + *
> + * @param time: Input location for the timestamp.
> + * @param sec: Output location for the value of the seconds.
> + * @param usec: Output location for the value of the microseconds.
> + */
> +void kshark_convert_nano(uint64_t time, uint64_t *sec, uint64_t *usec)
> +{
> + *sec = time / 1000000000ULL;
> + *usec = (time / 1000) % 1000000;
BTW, just a little optimization, as '%' and '/' are very expensive
operations, you can remove one by this:
{
uint64_t s;
s = time / 1000000000ULL;
*sec = s;
*usec = (time - s * 1000000000ULL) / 1000;
As '-' and '*' are fast operations.
-- Steve
> +}
> +
> /**
> * @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 f00a584..d24ed8c 100644
> --- a/kernel-shark-qt/src/libkshark.h
> +++ b/kernel-shark-qt/src/libkshark.h
> @@ -160,6 +160,8 @@ const char *kshark_get_event_name_easy(struct kshark_entry *entry);
>
> const char *kshark_get_info_easy(struct kshark_entry *entry);
>
> +void kshark_convert_nano(uint64_t time, uint64_t *sec, uint64_t *usec);
> +
> char* kshark_dump_entry(const struct kshark_entry *entry);
>
> struct tep_record *kshark_read_at(struct kshark_context *kshark_ctx,
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