Re: IFQ_ENQUEUE argument refactor (was Re: RFC: ALTQ caller refactor)

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

Hi,

Thank you for comments.

On 2016/04/11 17:11, Joerg Sonnenberger wrote:
> On Mon, Apr 11, 2016 at 01:06:00PM +0900, Kengo NAKAHARA wrote:
>> I implement moving struct altq_pktattr from m_tag to mbuf. Here is
>> the patch.
>>     http://www.netbsd.org/~knakahara/mbuf-altq-pktattr/mbuf-altq-pktattr.patch
> 
> The only issue here is that I would prefer to not add the ALTQ
> include, but just move the definition into sys/mbuf.h. Out of curiosity,

I see. I remove ALTQ include. Since I add individual fields in struct
pkthdrAs as you indicated following, I don't move strct altq_pktattr.

> is the new size the same if you add the fields individually and the int
> first? I.e. does using the struct add initial padding? It might be
> useful at some point later to drop altq_pktattr as separate type
> altogether and just use individual fields. As soon as some data after
> pattr has to be added, we get padding on LP64 otherwise.

Fair enough.
The new size is the same when I add the fields individually an the int
first. I change the fields order in several patterns, but the new size
is the same unless adding __packed attribute.
# with __packed, the size changes from 56 bytes to 52 bytes in LP64,
# in contrast, the size is the same in ILP32
However, I get padding when I add new uint32_t fields after pattr in
LP64. So, I modify to use individual fields for future works.
I ensured this changes does not cause performance issues in my measurement.

Here is the updated patch and patch series.
    - unified patch
      http://www.netbsd.org/~knakahara/mbuf-altq-pktattr/mbuf-altq-pktattr-2.patch
    - patch series
      http://www.netbsd.org/~knakahara/mbuf-altq-pktattr/0001-use-altq_pktattr-as-mbuf.patch
      http://www.netbsd.org/~knakahara/mbuf-altq-pktattr/0002-fix-caller-side.patch
      http://www.netbsd.org/~knakahara/mbuf-altq-pktattr/0003-more-refactor-to-fix-performance-issue.patch
      http://www.netbsd.org/~knakahara/mbuf-altq-pktattr/0004-improve-comment.patch
      http://www.netbsd.org/~knakahara/mbuf-altq-pktattr/0005-reviewed-by-joerg-n.o.patch

Could you comment this patch?


Thanks,

-- 
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Internet Initiative Japan Inc.

Device Engineering Section,
IoT Platform Development Department,
Network Division,
Technology Unit

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