From: Hiroyuki Mikita <h.mikita89@gmail.com>
To: Olivier Matz <olivier.matz@6wind.com>
Cc: Thomas Monjalon <thomas.monjalon@6wind.com>,
"Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3] mbuf: decrease refcnt when detaching
Date: Wed, 18 May 2016 23:29:12 +0900 [thread overview]
Message-ID: <CAO_n4D04bYSmVfRYtV05c8LJg-L3pkNRo-u93onu9BxFk=zmdQ@mail.gmail.com> (raw)
In-Reply-To: <573C58FE.3020101@6wind.com>
Hi Olivier,
Thanks for reviewing.
I am fixing the patch to follow your comments.
Regards,
Hiroyuki
2016-05-18 20:58 GMT+09:00 Olivier Matz <olivier.matz@6wind.com>:
> Hi Hiroyuki,
>
> Thanks for submitting a new version.
>
> There are some styling issues in the patch, I highlighted them below
> but you can check them by using checkpatch:
>
> DPDK_CHECKPATCH_PATH=/path/to/linux/checkpatch.pl \
> scripts/checkpatches.sh file.patch
>
>
> On 05/17/2016 06:35 PM, Hiroyuki Mikita wrote:
>> The rte_pktmbuf_detach() function should decrease refcnt on a direct
>> buffer.
>>
>> Signed-off-by: Hiroyuki Mikita <h.mikita89@gmail.com>
>>
>> [...]
>>
>> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
>> index 529debb..299b60e 100644
>> --- a/lib/librte_mbuf/rte_mbuf.h
>> +++ b/lib/librte_mbuf/rte_mbuf.h
>> @@ -1408,6 +1408,8 @@ static inline int rte_pktmbuf_alloc_bulk(struct rte_mempool *pool,
>> *
>> * After attachment we refer the mbuf we attached as 'indirect',
>> * while mbuf we attached to as 'direct'.
>> + * The direct mbuf's reference counter is incremented.
>> + *
>
> ERROR:TRAILING_WHITESPACE: trailing whitespace
> #82: FILE: lib/librte_mbuf/rte_mbuf.h:1412:
> + * $
>
>
>> * Right now, not supported:
>> * - attachment for already indirect mbuf (e.g. - mi has to be direct).
>> * - mbuf we trying to attach (mi) is used by someone else
>> @@ -1462,12 +1464,15 @@ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *m)
>> * - restore original mbuf address and length values.
>> * - reset pktmbuf data and data_len to their default values.
>> * All other fields of the given packet mbuf will be left intact.
>> + * - decrement the direct mbuf's reference counter.
>> + * When the reference counter becomes 0, the direct mbuf is freed.
>
> Minor comment here: I think something like that would be clearer:
>
> * - restore original mbuf address and length values.
> * - reset pktmbuf data and data_len to their default values.
> * - decrement the direct mbuf's reference counter. When the
> * reference counter becomes 0, the direct mbuf is freed.
> *
> * All other fields of the given packet mbuf will be left intact.
>
>
>> *
>> * @param m
>> * The indirect attached packet mbuf.
>> */
>> static inline void rte_pktmbuf_detach(struct rte_mbuf *m)
>> {
>> + struct rte_mbuf *md = rte_mbuf_from_indirect(m);
>> struct rte_mempool *mp = m->pool;
>> uint32_t mbuf_size, buf_len, priv_size;
>>
>> @@ -1482,6 +1487,10 @@ static inline void rte_pktmbuf_detach(struct rte_mbuf *m)
>> m->data_off = RTE_MIN(RTE_PKTMBUF_HEADROOM, (uint16_t)m->buf_len);
>> m->data_len = 0;
>> m->ol_flags = 0;
>> +
>> + if (rte_mbuf_refcnt_update(md, -1) == 0) {
>> + __rte_mbuf_raw_free(md);
>> + }
>> }
>
> WARNING:BRACES: braces {} are not necessary for single statement blocks
> #107: FILE: lib/librte_mbuf/rte_mbuf.h:1491:
> + if (rte_mbuf_refcnt_update(md, -1) == 0) {
> + __rte_mbuf_raw_free(md);
> + }
>
>
>>
>> static inline struct rte_mbuf* __attribute__((always_inline))
>> @@ -1491,15 +1500,9 @@ __rte_pktmbuf_prefree_seg(struct rte_mbuf *m)
>>
>> if (likely(rte_mbuf_refcnt_update(m, -1) == 0)) {
>>
>> - /* if this is an indirect mbuf, then
>> - * - detach mbuf
>> - * - free attached mbuf segment
>> - */
>> + /* if this is an indirect mbuf, it is detached. */
>> if (RTE_MBUF_INDIRECT(m)) {
>> - struct rte_mbuf *md = rte_mbuf_from_indirect(m);
>> rte_pktmbuf_detach(m);
>> - if (rte_mbuf_refcnt_update(md, -1) == 0)
>> - __rte_mbuf_raw_free(md);
>> }
>> return m;
>> }
>>
>
> It's not seen by checkpatch, but the braces could also be removed
> here.
>
> Apart from this, it looks good to me. I'm ok with not providing a
> compat function as we could consider it was a bug.
>
> Thanks for working on this.
>
> Olivier
>
next prev parent reply other threads:[~2016-05-18 14:29 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-15 15:50 [dpdk-dev] [PATCH] " Hiroyuki Mikita
2016-05-16 0:05 ` Ananyev, Konstantin
2016-05-16 2:46 ` Hiroyuki MIKITA
2016-05-16 8:49 ` Ananyev, Konstantin
2016-05-16 9:13 ` Thomas Monjalon
2016-05-16 16:24 ` Hiroyuki MIKITA
2016-05-16 8:52 ` Olivier Matz
2016-05-16 16:53 ` [dpdk-dev] [PATCH v2] " Hiroyuki Mikita
2016-05-17 10:58 ` Bruce Richardson
2016-05-17 11:06 ` Ananyev, Konstantin
2016-05-17 12:43 ` Thomas Monjalon
2016-05-17 12:59 ` Ananyev, Konstantin
2016-05-17 13:39 ` Thomas Monjalon
2016-05-17 13:44 ` Ananyev, Konstantin
2016-05-17 14:19 ` Thomas Monjalon
2016-05-17 15:45 ` Ananyev, Konstantin
2016-05-17 16:12 ` Hiroyuki MIKITA
2016-05-17 16:35 ` [dpdk-dev] [PATCH v3] " Hiroyuki Mikita
2016-05-18 11:58 ` Olivier Matz
2016-05-18 14:29 ` Hiroyuki Mikita [this message]
2016-05-18 14:41 ` [dpdk-dev] [PATCH v4] " Hiroyuki Mikita
2016-05-18 15:51 ` Olivier Matz
2016-05-19 12:38 ` Thomas Monjalon
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