From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Jens Freimann <jfreimann@redhat.com>
Cc: Tiwei Bie <tiwei.bie@intel.com>, zhihong.wang@intel.com, dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 05/10] net/virtio: refactor virtqueue structure
Date: Tue, 19 Mar 2019 14:50:50 +0100 [thread overview]
Message-ID: <1d05e311-c60b-cb1d-ff2b-974e01a0451b@redhat.com> (raw)
Message-ID: <20190319135050.xliWcsaNyV8Fd0NZUE5HvzbthdaYRJ0jfH8MHSpHSys@z> (raw)
In-Reply-To: <20190319134751.ibgaalfravjm77lh@jenstp.localdomain>
On 3/19/19 2:47 PM, Jens Freimann wrote:
> On Tue, Mar 19, 2019 at 02:28:30PM +0100, Maxime Coquelin wrote:
>>
>>
>> On 3/19/19 11:09 AM, Tiwei Bie wrote:
>>> On Tue, Mar 19, 2019 at 10:44:32AM +0100, Jens Freimann wrote:
>>>> On Tue, Mar 19, 2019 at 02:43:07PM +0800, Tiwei Bie wrote:
>>>>> Put split ring and packed ring specific fields into separate
>>>>> sub-structures, and also union them as they won't be available
>>>>> at the same time.
>>>>>
>>>>> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
>>>>> ---
>>>>> drivers/net/virtio/virtio_ethdev.c | 71 +++++++++---------
>>>>> drivers/net/virtio/virtio_rxtx.c | 66 ++++++++---------
>>>>> drivers/net/virtio/virtio_rxtx_simple.h | 2 +-
>>>>> drivers/net/virtio/virtio_rxtx_simple_neon.c | 2 +-
>>>>> drivers/net/virtio/virtio_rxtx_simple_sse.c | 2 +-
>>>>> drivers/net/virtio/virtqueue.c | 6 +-
>>>>> drivers/net/virtio/virtqueue.h | 77 +++++++++++---------
>>>>> 7 files changed, 117 insertions(+), 109 deletions(-)
>>>>>
>>>> [snip]
>>>> ...
>>>>> diff --git a/drivers/net/virtio/virtqueue.h
>>>>> b/drivers/net/virtio/virtqueue.h
>>>>> index 80c0c43c3..48b3912e6 100644
>>>>> --- a/drivers/net/virtio/virtqueue.h
>>>>> +++ b/drivers/net/virtio/virtqueue.h
>>>>> @@ -191,17 +191,22 @@ struct vq_desc_extra {
>>>>>
>>>>> struct virtqueue {
>>>>> struct virtio_hw *hw; /**< virtio_hw structure pointer. */
>>>>> - struct vring vq_ring; /**< vring keeping desc, used and avail */
>>>>> - struct vring_packed ring_packed; /**< vring keeping descs */
>>>>> - bool used_wrap_counter;
>>>>> - uint16_t cached_flags; /**< cached flags for descs */
>>>>> - uint16_t event_flags_shadow;
>>>>> + union {
>>>>> + struct {
>>>>> + /**< vring keeping desc, used and avail */
>>>>> + struct vring ring;
>>>>> + } vq_split;
>>>>>
>>>>> - /**
>>>>> - * Last consumed descriptor in the used table,
>>>>> - * trails vq_ring.used->idx.
>>>>> - */
>>>>> - uint16_t vq_used_cons_idx;
>>>>> + struct {
>>>>> + /**< vring keeping descs and events */
>>>>> + struct vring_packed ring;
>>>>> + bool used_wrap_counter;
>>>>> + uint16_t cached_flags; /**< cached flags for descs */
>>>>> + uint16_t event_flags_shadow;
>>>>> + } vq_packed;
>>>>> + };
>>>>> +
>>>>> + uint16_t vq_used_cons_idx; /**< last consumed descriptor */
>>>>> uint16_t vq_nentries; /**< vring desc numbers */
>>>>> uint16_t vq_free_cnt; /**< num of desc available */
>>>>> uint16_t vq_avail_idx; /**< sync until needed */
>>>>
>>>> Honest question: What do we really gain by putting it in a union? We
>>>> save a little memory. But we also make code less readable IMHO.
>>>
>>> I think it will make it clear that fields like used_wrap_counter
>>> are only available in packed ring which will make the code more
>>> readable.
>>>
>>>>
>>>> If we do this, can we at least shorten some variable names, like drop
>>>> the vq_ prefix? (It's used everywhere like vq->vq_packed*, so with
>>>> vq->packed* we don't loose any context).
>>>
>>> I prefer to have consistent prefix like most fields in this
>>> structure (although some fields don't really follow this).
>>
>> As Jens, I tend to agree that the vq_ prefix is quite redundant.
>> However, I think it is better to keep it in this patch for consistency.
>>
>> Maybe it can be remove in a separate patch later?
>
> I thought it might be convenient to change it now as we are touching
> all related code anyway. But I also don't want to block the patch
> because of
> this cosmetic thing. So let's defer it to a later patch set.
OK, when I meant later, I meant to remove vq_ prefix for all fields, not
only vq_split & vq_packed.
But yes, that's just cosmetic so let's keep it as is for now.
>
> regards,
> Jens
next prev parent reply other threads:[~2019-03-19 13:50 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-19 6:43 [dpdk-dev] [PATCH 00/10] net/virtio: cleanups and fixes for packed/split ring Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 6:43 ` [dpdk-dev] [PATCH 01/10] net/virtio: fix typo in packed ring init Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 8:39 ` Jens Freimann
2019-03-19 8:39 ` Jens Freimann
2019-03-19 12:46 ` Maxime Coquelin
2019-03-19 12:46 ` Maxime Coquelin
2019-03-19 6:43 ` [dpdk-dev] [PATCH 02/10] net/virtio: fix interrupt helper for packed ring Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 12:48 ` Maxime Coquelin
2019-03-19 12:48 ` Maxime Coquelin
2019-03-19 6:43 ` [dpdk-dev] [PATCH 03/10] net/virtio: add missing barrier in interrupt enable Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 12:49 ` Maxime Coquelin
2019-03-19 12:49 ` Maxime Coquelin
2019-03-19 6:43 ` [dpdk-dev] [PATCH 04/10] net/virtio: optimize flags update for packed ring Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 8:54 ` Jens Freimann
2019-03-19 8:54 ` Jens Freimann
2019-03-19 9:37 ` Tiwei Bie
2019-03-19 9:37 ` Tiwei Bie
2019-03-19 10:11 ` Jens Freimann
2019-03-19 10:11 ` Jens Freimann
2019-03-19 12:50 ` Maxime Coquelin
2019-03-19 12:50 ` Maxime Coquelin
2019-03-19 12:58 ` Maxime Coquelin
2019-03-19 12:58 ` Maxime Coquelin
2019-03-19 6:43 ` [dpdk-dev] [PATCH 05/10] net/virtio: refactor virtqueue structure Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 9:44 ` Jens Freimann
2019-03-19 9:44 ` Jens Freimann
2019-03-19 10:09 ` Tiwei Bie
2019-03-19 10:09 ` Tiwei Bie
2019-03-19 13:28 ` Maxime Coquelin
2019-03-19 13:28 ` Maxime Coquelin
2019-03-19 13:47 ` Jens Freimann
2019-03-19 13:47 ` Jens Freimann
2019-03-19 13:50 ` Maxime Coquelin [this message]
2019-03-19 13:50 ` Maxime Coquelin
2019-03-19 14:59 ` Kevin Traynor
2019-03-19 14:59 ` Kevin Traynor
2019-03-20 4:40 ` Tiwei Bie
2019-03-20 4:40 ` Tiwei Bie
2019-03-20 17:50 ` Stephen Hemminger
2019-03-20 17:50 ` Stephen Hemminger
2019-03-21 14:18 ` Maxime Coquelin
2019-03-21 14:18 ` Maxime Coquelin
2019-03-20 4:35 ` Tiwei Bie
2019-03-20 4:35 ` Tiwei Bie
2019-03-19 13:28 ` Maxime Coquelin
2019-03-19 13:28 ` Maxime Coquelin
2019-03-19 6:43 ` [dpdk-dev] [PATCH 06/10] net/virtio: drop redundant suffix in packed ring structure Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 9:47 ` Jens Freimann
2019-03-19 9:47 ` Jens Freimann
2019-03-19 13:29 ` Maxime Coquelin
2019-03-19 13:29 ` Maxime Coquelin
2019-03-19 6:43 ` [dpdk-dev] [PATCH 07/10] net/virtio: drop unused field in Tx region structure Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 9:51 ` Jens Freimann
2019-03-19 9:51 ` Jens Freimann
2019-03-19 13:33 ` Maxime Coquelin
2019-03-19 13:33 ` Maxime Coquelin
2019-03-19 6:43 ` [dpdk-dev] [PATCH 08/10] net/virtio: add interrupt helper for split ring Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 9:53 ` Jens Freimann
2019-03-19 9:53 ` Jens Freimann
2019-03-19 13:34 ` Maxime Coquelin
2019-03-19 13:34 ` Maxime Coquelin
2019-03-19 6:43 ` [dpdk-dev] [PATCH 09/10] net/virtio: add ctrl vq " Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 9:54 ` Jens Freimann
2019-03-19 9:54 ` Jens Freimann
2019-03-19 13:54 ` Maxime Coquelin
2019-03-19 13:54 ` Maxime Coquelin
2019-03-19 6:43 ` [dpdk-dev] [PATCH 10/10] net/virtio: improve batching in standard Rx path Tiwei Bie
2019-03-19 6:43 ` Tiwei Bie
2019-03-19 10:04 ` Jens Freimann
2019-03-19 10:04 ` Jens Freimann
2019-03-19 10:28 ` Tiwei Bie
2019-03-19 10:28 ` Tiwei Bie
2019-03-19 11:08 ` Maxime Coquelin
2019-03-19 11:08 ` Maxime Coquelin
2019-03-19 14:15 ` Maxime Coquelin
2019-03-19 14:15 ` Maxime Coquelin
2019-03-20 7:35 ` [dpdk-dev] [PATCH 00/10] net/virtio: cleanups and fixes for packed/split ring Maxime Coquelin
2019-03-20 7:35 ` Maxime Coquelin
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