From: Olivier Matz <olivier.matz@6wind.com>
To: Hiroyuki Mikita <h.mikita89@gmail.com>,
thomas.monjalon@6wind.com, konstantin.ananyev@intel.com
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3] mbuf: decrease refcnt when detaching
Date: Wed, 18 May 2016 13:58:54 +0200 [thread overview]
Message-ID: <573C58FE.3020101@6wind.com> (raw)
In-Reply-To: <1463502902-5295-1-git-send-email-h.mikita89@gmail.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 11:59 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 [this message]
2016-05-18 14:29 ` Hiroyuki Mikita
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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