From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Zhihong Wang <zhihong.wang@intel.com>,
dev@dpdk.org, thomas.monjalon@6wind.com
Subject: Re: [dpdk-dev] [PATCH v6 0/6] vhost: optimize enqueue
Date: Wed, 21 Sep 2016 06:39:50 +0200 [thread overview]
Message-ID: <48715e6b-5f7e-0781-f794-07c5dd29e15a@redhat.com> (raw)
In-Reply-To: <20160921022656.GA23158@yliu-dev.sh.intel.com>
Hi Yuanhan,
On 09/21/2016 04:26 AM, Yuanhan Liu wrote:
> Hi Maxime,
>
> Do you have more comments about this set? If no, I think I could merge
> it shortly.
No more comments, this is good to me.
Feel free to add:
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
> Thanks.
>
> --yliu
>
> On Mon, Sep 19, 2016 at 10:00:11PM -0400, Zhihong Wang wrote:
>> This patch set optimizes the vhost enqueue function.
>>
>> It implements the vhost logic from scratch into a single function designed
>> for high performance and good maintainability, and improves CPU efficiency
>> significantly by optimizing cache access, which means:
>>
>> * Higher maximum throughput can be achieved for fast frontends like DPDK
>> virtio pmd.
>>
>> * Better scalability can be achieved that each vhost core can support
>> more connections because it takes less cycles to handle each single
>> frontend.
>>
>> This patch set contains:
>>
>> 1. A Windows VM compatibility fix for vhost enqueue in 16.07 release.
>>
>> 2. A baseline patch to rewrite the vhost logic.
>>
>> 3. A series of optimization patches added upon the baseline.
>>
>> The main optimization techniques are:
>>
>> 1. Reorder code to reduce CPU pipeline stall cycles.
>>
>> 2. Batch update the used ring for better efficiency.
>>
>> 3. Prefetch descriptor to hide cache latency.
>>
>> 4. Remove useless volatile attribute to allow compiler optimization.
>>
>> Code reordering and batch used ring update bring most of the performance
>> improvements.
>>
>> In the existing code there're 2 callbacks for vhost enqueue:
>>
>> * virtio_dev_merge_rx for mrg_rxbuf turned on cases.
>>
>> * virtio_dev_rx for mrg_rxbuf turned off cases.
>>
>> The performance of the existing code is not optimal, especially when the
>> mrg_rxbuf feature turned on. Besides, having 2 callback paths increases
>> maintenance efforts.
>>
>> Also, there's a compatibility issue in the existing code which causes
>> Windows VM to hang when the mrg_rxbuf feature turned on.
>>
>> ---
>> Changes in v6:
>>
>> 1. Merge duplicated code.
>>
>> 2. Introduce a function for used ring write.
>>
>> 3. Add necessary comments.
>>
>> ---
>> Changes in v5:
>>
>> 1. Rebase to dpdk-next-virtio master.
>>
>> 2. Rename variables to keep consistent in naming style.
>>
>> 3. Small changes like return value adjustment and vertical alignment.
>>
>> 4. Add details in commit log.
>>
>> ---
>> Changes in v4:
>>
>> 1. Fix a Windows VM compatibility issue.
>>
>> 2. Free shadow used ring in the right place.
>>
>> 3. Add failure check for shadow used ring malloc.
>>
>> 4. Refactor the code for clearer logic.
>>
>> 5. Add PRINT_PACKET for debugging.
>>
>> ---
>> Changes in v3:
>>
>> 1. Remove unnecessary memset which causes frontend stall on SNB & IVB.
>>
>> 2. Rename variables to follow naming convention.
>>
>> 3. Rewrite enqueue and delete the obsolete in the same patch.
>>
>> ---
>> Changes in v2:
>>
>> 1. Split the big function into several small ones.
>>
>> 2. Use multiple patches to explain each optimization.
>>
>> 3. Add comments.
>>
>> Zhihong Wang (6):
>> vhost: fix windows vm hang
>> vhost: rewrite enqueue
>> vhost: remove useless volatile
>> vhost: add desc prefetch
>> vhost: batch update used ring
>> vhost: optimize cache access
>>
>> lib/librte_vhost/vhost.c | 20 +-
>> lib/librte_vhost/vhost.h | 6 +-
>> lib/librte_vhost/vhost_user.c | 31 ++-
>> lib/librte_vhost/virtio_net.c | 541 ++++++++++++++----------------------------
>> 4 files changed, 225 insertions(+), 373 deletions(-)
>>
>> --
>> 2.7.4
next prev parent reply other threads:[~2016-09-21 4:39 UTC|newest]
Thread overview: 140+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-16 3:50 [dpdk-dev] [PATCH] optimize vhost enqueue Zhihong Wang
2016-08-16 13:59 ` Maxime Coquelin
2016-08-17 1:45 ` Wang, Zhihong
2016-08-17 2:38 ` Yuanhan Liu
2016-08-17 6:41 ` Wang, Zhihong
2016-08-17 9:17 ` Maxime Coquelin
2016-08-17 9:51 ` Yuanhan Liu
2016-08-18 13:44 ` Wang, Zhihong
2016-08-17 10:07 ` Wang, Zhihong
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 0/6] vhost: optimize enqueue Zhihong Wang
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 1/6] vhost: rewrite enqueue Zhihong Wang
2016-08-19 2:39 ` Yuanhan Liu
2016-08-19 7:07 ` Wang, Zhihong
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 2/6] vhost: remove obsolete Zhihong Wang
2016-08-19 2:32 ` Yuanhan Liu
2016-08-19 7:08 ` Wang, Zhihong
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 3/6] vhost: remove useless volatile Zhihong Wang
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 4/6] vhost: add desc prefetch Zhihong Wang
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 5/6] vhost: batch update used ring Zhihong Wang
2016-08-18 6:33 ` [dpdk-dev] [PATCH v2 6/6] vhost: optimize cache access Zhihong Wang
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 0/5] vhost: optimize enqueue Zhihong Wang
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 1/5] vhost: rewrite enqueue Zhihong Wang
2016-08-22 9:35 ` Maxime Coquelin
2016-08-23 2:27 ` Wang, Zhihong
2016-08-25 4:00 ` Yuanhan Liu
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 2/5] vhost: remove useless volatile Zhihong Wang
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 3/5] vhost: add desc prefetch Zhihong Wang
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 4/5] vhost: batch update used ring Zhihong Wang
2016-08-25 3:48 ` Yuanhan Liu
2016-08-25 5:19 ` Wang, Zhihong
2016-08-19 5:43 ` [dpdk-dev] [PATCH v3 5/5] vhost: optimize cache access Zhihong Wang
2016-08-22 8:11 ` [dpdk-dev] [PATCH v3 0/5] vhost: optimize enqueue Maxime Coquelin
2016-08-22 10:01 ` Maxime Coquelin
2016-08-22 10:35 ` Thomas Monjalon
2016-08-24 3:37 ` Wang, Zhihong
2016-08-23 2:31 ` Wang, Zhihong
2016-08-23 10:43 ` Wang, Zhihong
2016-08-23 12:16 ` Maxime Coquelin
2016-08-23 12:22 ` Yuanhan Liu
2016-08-23 2:15 ` Wang, Zhihong
2016-09-21 8:50 ` Jianbo Liu
2016-09-21 9:27 ` Wang, Zhihong
2016-09-21 12:54 ` Jianbo Liu
2016-09-22 2:11 ` Wang, Zhihong
2016-09-22 2:29 ` Yuanhan Liu
2016-09-22 5:47 ` Jianbo Liu
2016-09-22 6:58 ` Wang, Zhihong
2016-09-22 9:01 ` Jianbo Liu
2016-09-22 10:04 ` Wang, Zhihong
2016-09-22 14:41 ` Jianbo Liu
2016-09-23 2:56 ` Wang, Zhihong
2016-09-23 10:41 ` Jianbo Liu
2016-09-23 13:41 ` Thomas Monjalon
2016-09-25 5:41 ` Wang, Zhihong
2016-09-26 5:12 ` Jianbo Liu
2016-09-26 5:25 ` Wang, Zhihong
2016-09-26 5:38 ` Jianbo Liu
2016-09-26 6:00 ` Wang, Zhihong
2016-09-26 4:24 ` Jianbo Liu
2016-09-26 5:37 ` Luke Gorrie
2016-09-26 5:40 ` Jianbo Liu
2016-09-27 10:21 ` Yuanhan Liu
2016-09-27 16:45 ` Wang, Zhihong
2016-10-09 12:09 ` Wang, Zhihong
2016-10-10 2:44 ` Yuanhan Liu
2016-10-10 5:31 ` Jianbo Liu
2016-10-10 6:22 ` Wang, Zhihong
2016-10-10 6:57 ` Jianbo Liu
2016-10-10 7:25 ` Wang, Zhihong
2016-10-12 2:53 ` Yuanhan Liu
2016-10-12 12:22 ` Wang, Zhihong
2016-10-12 15:31 ` Thomas Monjalon
2016-10-13 1:21 ` Wang, Zhihong
2016-10-13 3:51 ` Jianbo Liu
2016-10-13 5:33 ` Yuanhan Liu
2016-10-13 5:35 ` Yuanhan Liu
2016-10-13 6:02 ` Wang, Zhihong
2016-10-13 7:54 ` Maxime Coquelin
2016-10-13 9:23 ` Maxime Coquelin
2016-10-14 10:11 ` Yuanhan Liu
2016-08-30 3:35 ` [dpdk-dev] [PATCH v4 0/6] " Zhihong Wang
2016-08-30 3:35 ` [dpdk-dev] [PATCH v4 1/6] vhost: fix windows vm hang Zhihong Wang
2016-09-05 5:24 ` [dpdk-dev] [dpdk-stable] " Yuanhan Liu
2016-09-05 5:25 ` Wang, Zhihong
2016-09-05 5:40 ` Yuanhan Liu
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 2/6] vhost: rewrite enqueue Zhihong Wang
2016-09-05 6:39 ` Yuanhan Liu
2016-09-07 5:33 ` Yuanhan Liu
2016-09-07 5:39 ` Wang, Zhihong
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 3/6] vhost: remove useless volatile Zhihong Wang
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 4/6] vhost: add desc prefetch Zhihong Wang
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 5/6] vhost: batch update used ring Zhihong Wang
2016-08-30 3:36 ` [dpdk-dev] [PATCH v4 6/6] vhost: optimize cache access Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 0/6] vhost: optimize enqueue Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 1/6] vhost: fix windows vm hang Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 2/6] vhost: rewrite enqueue Zhihong Wang
2016-09-12 15:42 ` Maxime Coquelin
2016-09-14 8:20 ` Wang, Zhihong
2016-09-15 16:35 ` Maxime Coquelin
2016-09-12 16:26 ` Maxime Coquelin
2016-09-14 8:22 ` Wang, Zhihong
2016-09-18 14:19 ` Yuanhan Liu
2016-09-19 3:29 ` Wang, Zhihong
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 3/6] vhost: remove useless volatile Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 4/6] vhost: add desc prefetch Zhihong Wang
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 5/6] vhost: batch update used ring Zhihong Wang
2016-09-12 15:45 ` Maxime Coquelin
2016-09-14 8:43 ` Wang, Zhihong
2016-09-15 16:38 ` Maxime Coquelin
2016-09-18 2:55 ` Yuanhan Liu
2016-09-18 2:57 ` Wang, Zhihong
2016-09-09 3:39 ` [dpdk-dev] [PATCH v5 6/6] vhost: optimize cache access Zhihong Wang
2016-09-12 13:52 ` [dpdk-dev] [PATCH v5 0/6] vhost: optimize enqueue Maxime Coquelin
2016-09-12 13:56 ` Maxime Coquelin
2016-09-12 14:01 ` Yuanhan Liu
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 " Zhihong Wang
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 1/6] vhost: fix windows vm hang Zhihong Wang
2016-10-13 6:18 ` [dpdk-dev] [dpdk-stable] " Yuanhan Liu
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 2/6] vhost: rewrite enqueue Zhihong Wang
2016-09-22 9:58 ` Jianbo Liu
2016-09-22 10:13 ` Wang, Zhihong
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 3/6] vhost: remove useless volatile Zhihong Wang
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 4/6] vhost: add desc prefetch Zhihong Wang
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 5/6] vhost: batch update used ring Zhihong Wang
2016-09-20 2:00 ` [dpdk-dev] [PATCH v6 6/6] vhost: optimize cache access Zhihong Wang
2016-09-21 2:26 ` [dpdk-dev] [PATCH v6 0/6] vhost: optimize enqueue Yuanhan Liu
2016-09-21 4:39 ` Maxime Coquelin [this message]
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 0/7] vhost: optimize mergeable Rx path Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 1/7] vhost: remove useless volatile Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 2/7] vhost: optimize cache access Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 3/7] vhost: simplify mergeable Rx vring reservation Yuanhan Liu
2016-10-25 22:08 ` Thomas Monjalon
2016-10-26 2:56 ` Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 4/7] vhost: use last avail idx for avail ring reservation Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 5/7] vhost: shadow used ring update Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 6/7] vhost: prefetch avail ring Yuanhan Liu
2016-10-14 9:34 ` [dpdk-dev] [PATCH v7 7/7] vhost: retrieve avail head once Yuanhan Liu
2016-10-18 2:25 ` [dpdk-dev] [PATCH v7 0/7] vhost: optimize mergeable Rx path Jianbo Liu
2016-10-18 14:53 ` Maxime Coquelin
2016-10-21 7:51 ` Yuanhan Liu
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