From: Andrew Rybchenko <arybchenko@solarflare.com>
To: Dan Gora <dg@adax.com>, "Wiles, Keith" <keith.wiles@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>, Olivier Matz <olivier.matz@6wind.com>
Subject: Re: [dpdk-dev] [PATCH 1/4] mbuf: add accessor function for private data area
Date: Sat, 9 Jun 2018 12:23:21 +0300 [thread overview]
Message-ID: <b3a9fedf-2ada-973e-c8b1-5b0154508771@solarflare.com> (raw)
In-Reply-To: <CAGyogRb5AWtkVenEu0nPjsVMTuRDm9P-Ta0LybsaKMiprnxYSw@mail.gmail.com>
Hi Dan,
On 06/09/2018 03:24 AM, Dan Gora wrote:
>>>> +{
>>>> + if (md->priv_size == 0)
>>>> + return NULL;
>>>> +
>>>> + return RTE_PTR_ADD(md, sizeof(struct rte_mbuf));
>>> Also a nit...
>>> I'd use sizeof(*md) (or sizeof(*m) in fact as described above) here.
>>> At least previous functions do it in such way.
>> I believe the sizeof(struct rte_mbuf) is much more readable then sizeof(*m) it makes the reader have to look up what ‘m’ is defined to. I know this is a small function, but readability is still a good reason to not use sizeof(*m) IMO.
> On one hand, using sizeof(*m) is useful in case the type of 'm' ever
> changes, you don't have to remember to change the arguments to sizeof.
> On the other hand, it does make it slightly harder to read, but not a
> lot really.
>
> For me, it's six one way, half a dozen the other. I just cut-pasted
> this from the ipsec-secgw code. I'm kind of inclined to leave it
> sizeof(struct rte_mbuf) just to leave it clear.
OK, I agree.
> Any opinion on my question from the cover letter?
Sorry, I was going to reply as I understand it, but forgot.
> Specifically when should rte_mbuf_XXX be used vs rte_pktmbuf_XXX for
> mbuf API functions? Why is there this inconsistency there? Are they
> just historical names which couldn't get changed?
I think that Olivier is best placed to answer it.
As I understand it is mainly historical right now, since ctrlmbuf API was
removed recently. For me, there is still a flavour of packet head in
pktmbuf,
but boundaries are so vague.
> One more quick question:
>
> When sending a v2 of a patch series, should I resend the whole bundle,
> even if there are no changes in the other patches or just send a v2 of
> the patch which actually contains changes from the v1 version?
All patches should be resent in v2.
BTW, thinking about function I found out there is a trap in private area
size related to the function. I think that the function description should
highlight that rte_pktmbuf_priv_size(m->pool) should be used to
find out the size of private area since indirect mbuf has size of the
direct private are in its priv_size (but we return pointer to the indirect
mbuf (the mbuf itself) private area here).
Andrew.
next prev parent reply other threads:[~2018-06-09 9:23 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-07 23:54 Dan Gora
2018-06-08 8:30 ` Burakov, Anatoly
2018-06-08 9:06 ` Andrew Rybchenko
2018-06-08 17:19 ` Wiles, Keith
2018-06-09 0:24 ` Dan Gora
2018-06-09 9:23 ` Andrew Rybchenko [this message]
2018-06-12 2:24 ` Dan Gora
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