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From: Remy NOEL <remy.noel@blade-group.com>
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Date: Mon, 24 Dec 2018 13:38:47 +0100
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Subject: Re: [Qemu-devel] [QEMU-devel][PATCH v4 0/2] Fix concurrent
 aio_poll/set_fd_handler.
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To: Paolo Bonzini <pbonzini@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>
Cc: qemu-devel@nongnu.org, Fam Zheng <famz@redhat.com>, Stefan Weil <sw@weilnetz.de>

On 12/21/18 12:34 PM, Paolo Bonzini wrote:

> FWIW, I had missed the early version that used RCU, but lockcnt is
> already very RCU-like, so not using RCU is the right thing to do.  The
> difference between lockcnt and RCU is that cleanup is done by the reader
> instead of a separate thread.  Because we know that reader/writer
> concurrency is very rare for AioContext handlers, the tradeoffs favor
> lockcnt over RCU.

Indeed, i forgot to CC you in the first batch (get_maintainer.pl was not 
finding you).

Thanks for the RCU hints, i though the performance hit was due to the 
RCU being global to qemu.


Remy