From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: dev@dpdk.org, jianfeng.tan@intel.com, tiwei.bie@intel.com,
jfreimann@redhat.com
Cc: stable@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] vhost: avoid concurrency when logging dirty pages
Date: Fri, 30 Mar 2018 09:42:39 +0200 [thread overview]
Message-ID: <efab884b-0322-13f4-c842-65ee5cddec21@redhat.com> (raw)
In-Reply-To: <20180321154413.1120-1-maxime.coquelin@redhat.com>
On 03/21/2018 04:44 PM, Maxime Coquelin wrote:
> This patch aims at fixing a migration performance regression
> faced since atomic operation is used to log pages as dirty when
> doing live migration.
>
> Instead of setting a single bit by doing an atomic read-modify-write
> operation to log a page as dirty, this patch write 0xFF to the
> corresponding byte, and so logs 8 page as dirty.
>
> The advantage is that it avoids concurrent atomic operations by
> multiple PMD threads, the drawback is that some clean pages are
> marked as dirty and so are transferred twice.
>
> Fixes: 897f13a1f726 ("vhost: make page logging atomic")
> Cc: stable@dpdk.org
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
> lib/librte_vhost/vhost.h | 12 ++++--------
> 1 file changed, 4 insertions(+), 8 deletions(-)
Applied to dpdk-next-virtio/master.
prev parent reply other threads:[~2018-03-30 7:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-21 15:44 Maxime Coquelin
2018-03-27 1:15 ` Tan, Jianfeng
2018-03-27 11:24 ` Maxime Coquelin
2018-03-30 7:42 ` Maxime Coquelin [this message]
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