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From: Stefan Hajnoczi <stefanha@gmail.com>
To: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Fam Zheng <fam@euphon.net>, Paolo Bonzini <pbonzini@redhat.com>,
	qemu-devel@nongnu.org, qemu-block@nongnu.org
Subject: Re: [PATCH] aio-posix: avoid reacquiring rcu_read_lock() when polling
Date: Fri, 21 Feb 2020 13:34:54 +0000	[thread overview]
Message-ID: <20200221133454.GJ1484511@stefanha-x1.localdomain> (raw)
In-Reply-To: <20200218182708.914552-1-stefanha@redhat.com>

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On Tue, Feb 18, 2020 at 06:27:08PM +0000, Stefan Hajnoczi wrote:
> The first rcu_read_lock/unlock() is expensive.  Nested calls are cheap.
> 
> This optimization increases IOPS from 73k to 162k with a Linux guest
> that has 2 virtio-blk,num-queues=1 and 99 virtio-blk,num-queues=32
> devices.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  util/aio-posix.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan

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      parent reply	other threads:[~2020-02-21 13:43 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-18 18:27 [PATCH] aio-posix: avoid reacquiring rcu_read_lock() when polling Stefan Hajnoczi
2020-02-20 11:19 ` Paolo Bonzini
2020-02-21 13:34 ` Stefan Hajnoczi [this message]

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