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From: John Garry <john.garry@huawei.com>
To: Cong Wang <xiyou.wangcong@gmail.com>, <iommu@lists.linux-foundation.org>
Cc: <linux-kernel@vger.kernel.org>
Subject: Re: [Patch v3 0/3] iommu: reduce spinlock contention on fast path
Date: Tue, 10 Dec 2019 14:53:25 +0000	[thread overview]
Message-ID: <5d517a33-2e5a-529c-578c-707ae0a40e88@huawei.com> (raw)
In-Reply-To: <20191206213803.12580-1-xiyou.wangcong@gmail.com>

On 06/12/2019 21:38, Cong Wang wrote:
> This patchset contains three small optimizations for the global spinlock
> contention in IOVA cache. Our memcache perf test shows this reduced its
> p999 latency down by 45% on AMD when IOMMU is enabled.
> 
> Cong Wang (3):
>    iommu: avoid unnecessary magazine allocations
>    iommu: optimize iova_magazine_free_pfns()
>    iommu: avoid taking iova_rbtree_lock twice
> ---
>   drivers/iommu/iova.c | 75 ++++++++++++++++++++++++++------------------
>   1 file changed, 45 insertions(+), 30 deletions(-)
> 

I retested, and got a ~1.1% gain in throughput for my storage test - 
results here if interested https://pastebin.com/dSQxYpN8

Thanks,
John

WARNING: multiple messages have this Message-ID (diff)
From: John Garry <john.garry@huawei.com>
To: Cong Wang <xiyou.wangcong@gmail.com>, <iommu@lists.linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [Patch v3 0/3] iommu: reduce spinlock contention on fast path
Date: Tue, 10 Dec 2019 14:53:25 +0000	[thread overview]
Message-ID: <5d517a33-2e5a-529c-578c-707ae0a40e88@huawei.com> (raw)
In-Reply-To: <20191206213803.12580-1-xiyou.wangcong@gmail.com>

On 06/12/2019 21:38, Cong Wang wrote:
> This patchset contains three small optimizations for the global spinlock
> contention in IOVA cache. Our memcache perf test shows this reduced its
> p999 latency down by 45% on AMD when IOMMU is enabled.
> 
> Cong Wang (3):
>    iommu: avoid unnecessary magazine allocations
>    iommu: optimize iova_magazine_free_pfns()
>    iommu: avoid taking iova_rbtree_lock twice
> ---
>   drivers/iommu/iova.c | 75 ++++++++++++++++++++++++++------------------
>   1 file changed, 45 insertions(+), 30 deletions(-)
> 

I retested, and got a ~1.1% gain in throughput for my storage test - 
results here if interested https://pastebin.com/dSQxYpN8

Thanks,
John
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https://lists.linuxfoundation.org/mailman/listinfo/iommu

  parent reply	other threads:[~2019-12-10 14:53 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-06 21:38 [Patch v3 0/3] iommu: reduce spinlock contention on fast path Cong Wang
2019-12-06 21:38 ` Cong Wang
2019-12-06 21:38 ` [Patch v3 1/3] iommu: avoid unnecessary magazine allocations Cong Wang
2019-12-06 21:38   ` Cong Wang
2019-12-06 21:38 ` [Patch v3 2/3] iommu: optimize iova_magazine_free_pfns() Cong Wang
2019-12-06 21:38   ` Cong Wang
2019-12-06 21:38 ` [Patch v3 3/3] iommu: avoid taking iova_rbtree_lock twice Cong Wang
2019-12-06 21:38   ` Cong Wang
2019-12-06 21:57 ` [Patch v3 0/3] iommu: reduce spinlock contention on fast path Qian Cai
2019-12-06 21:57   ` Qian Cai
2019-12-10 14:53 ` John Garry [this message]
2019-12-10 14:53   ` John Garry
2019-12-18  4:39 Cong Wang
2019-12-18  4:39 ` Cong Wang
2020-01-20 23:10 ` Cong Wang
2020-01-20 23:10   ` Cong Wang

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