Re: RFC: m_tag pool cache

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi,

On 2016/02/19 19:38, Joerg Sonnenberger wrote:
> On Fri, Feb 19, 2016 at 06:26:14PM +0900, Kengo NAKAHARA wrote:
>> Of course, m_tag_get() is used by packet processing path, this overhead
>> would have a certain influence on packet throughput and latency.
>> So, I think m_tag should use a dedicated pool cache like mbuf to call
>> pool_cache_get() directly.
> 
> Which tags are you actually seeing allocated? It would be better to
> remove the tags in first place if they are hot enough...

I am seeing a struct altq_pktattr tag, which is used to refactor ALTQ
in my working modification. I think ALTQ code would become better than
now by using altq_pktattr tag...
# The altq_pktattr tag is also used by sys/dist/pf/net/pf.c, so I think
# the result affect NetBSD-current itself.

I agree it should be removed in first place. However, I think there is
several cases which cannot avoid to use m_tag. So, it may be required
to rescue such cases.


Thanks,

-- 
//////////////////////////////////////////////////////////////////////
Internet Initiative Japan Inc.

Device Engineering Section,
Core Product Development Department,
Product Division,
Technology Unit

Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>