From: Will Deacon <will.deacon@arm.com>
To: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [PATCH] kvmtool: Add parameter to specifiy number of threads in thread_pool
Date: Mon, 29 Jun 2015 10:45:03 +0100 [thread overview]
Message-ID: <20150629094502.GA17474@arm.com> (raw)
In-Reply-To: <20150629074544.GA15313@alberich>
On Mon, Jun 29, 2015 at 08:45:44AM +0100, Andreas Herrmann wrote:
>
> With current code the number of threads added to the thread_pool
> equals number of online CPUs. Thus on an OcteonIII cn78xx system we
> usually have 48 threads per guest just for the thread_pool. IMHO this
> is overkill for guests that just have a few vCPUs and/or if a guest is
> pinned to a subset of host CPUs. E.g.
>
> # numactl -C 4,5,7,8 ./lkvm run -c 2 -m 256 -k paravirt -d rootfs.ext3 ...
> # ps -La | grep threadpool-work | wc -l
> 48
>
> Don't change default behaviour (for sake of compatibility) but
> introduce a new parameter ("-t" or "--threads") that allows to specify
> number of threads to be created for the thread_pool:
>
> # numactl -C 4,5,7,8 ./lkvm run -c 2 -m 256 --threads 4 -k paravirt -d ...
> # ps -La | grep threadpool-work | wc -l
> 4
We should probably bound this on some minimum value. I assume things go
pear-shaped if you pass --threads 1 (or 0, or -1)?
Will
next prev parent reply other threads:[~2015-06-29 9:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-29 7:45 [PATCH] kvmtool: Add parameter to specifiy number of threads in thread_pool Andreas Herrmann
2015-06-29 9:45 ` Will Deacon [this message]
2015-06-29 10:14 ` Andreas Herrmann
2015-06-29 11:43 ` [PATCH v2] " Andreas Herrmann
2015-06-30 14:03 ` Will Deacon
-- strict thread matches above, loose matches on Subject: below --
2015-01-06 13:13 [PATCH] " Andreas Herrmann
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