Hi,
On 2016/02/19 19:01, Thomas Klausner wrote:
> On Fri, Feb 19, 2016 at 06:26:14PM +0900, Kengo NAKAHARA wrote:
>> According to my measurements of using DTrace, there is a certain
>> overhead between kern_malloc() and pool_cache_get(). Here is each
>> function's average turnaround times in my measurement.
>>
>> m_tag_get | 124205 [ns]
>> kern_malloc | 108007 [ns]
>> kmem_intr_alloc | 89636 [ns]
>> pool_cache_get_paddr | 65942 [ns]
>
> For people like me who are new to dtrace, can you please post the
> dtrace script you used to measure?
Sure, I used dscript such as the following.
====================
fbt::m_tag_get:entry
{
self->trace_on = 1;
self->start[probefunc] = timestamp;
}
fbt::m_tag_get:return
{
self->trace_on = 0;
@turnaround[probefunc] = avg(timestamp - self->start[probefunc]);
}
fbt:::entry
/ self->trace_on == 1 /
{
self->start[probefunc] = timestamp;
}
fbt:::return
/ self->trace_on == 1 /
{
@turnaround[probefunc] = avg(timestamp - self->start[probefunc]);
}
END
{
printa(@turnaround);
}
====================
I often use the following web site as a reference.
http://dtrace.org/guide/preface.html
Thanks,
--
//////////////////////////////////////////////////////////////////////
Internet Initiative Japan Inc.
Device Engineering Section,
Core Product Development Department,
Product Division,
Technology Unit
Kengo NAKAHARA <k-nakah...@iij.ad.jp>
