From: Tiwei Bie <tiwei.bie@intel.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: dev@dpdk.org, mst@redhat.com, stable@dpdk.org
Subject: Re: [dpdk-stable] [PATCH v3] vhost: improve dirty pages logging performance
Date: Thu, 17 May 2018 10:04:31 +0800 [thread overview]
Message-ID: <20180517020431.GA26242@debian> (raw)
In-Reply-To: <20180516165423.5430-1-maxime.coquelin@redhat.com>
On Wed, May 16, 2018 at 06:54:23PM +0200, Maxime Coquelin wrote:
> This patch caches all dirty pages logging until the used ring index
> is updated.
>
> The goal of this optimization is to fix a performance regression
> introduced when the vhost library started to use atomic operations
> to set bits in the shared dirty log map. While the fix was valid
> as previous implementation wasn't safe against concurent accesses,
Typo: concurent
> contention was induced.
>
> With this patch, during migration, we have:
> 1. Less atomic operations as only a single atomic OR operation
> per 32 or 64 (depending on CPU) pages.
> 2. Less atomic operations as during a burst, the same page will
> be marked dirty only once.
> 3. Less write memory barriers.
>
> Fixes: 897f13a1f726 ("vhost: make page logging atomic")
>
> Cc: stable@dpdk.org
>
> Cc: Tiwei Bie <tiwei.bie@intel.com>
> Suggested-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Apart from the typo,
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
next prev parent reply other threads:[~2018-05-17 2:04 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-16 16:54 Maxime Coquelin
2018-05-17 2:04 ` Tiwei Bie [this message]
2018-05-17 3:06 ` Michael S. Tsirkin
2018-05-17 4:50 ` Tiwei Bie
2018-05-17 11:40 ` Maxime Coquelin
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