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From: "Roger Pau Monné" <roger.pau@citrix.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: SeongJae Park <sjpark@amazon.com>,
	SeongJae Park <sjpark@amazon.de>, <axboe@kernel.dk>,
	<aliguori@amazon.com>, <amit@kernel.org>, <mheyne@amazon.de>,
	<linux-block@vger.kernel.org>, <xen-devel@lists.xenproject.org>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] xen-blkback: add a parameter for disabling of persistent grants
Date: Thu, 24 Sep 2020 12:13:44 +0200	[thread overview]
Message-ID: <20200924101344.GN19254@Air-de-Roger> (raw)
In-Reply-To: <20200923200930.GB11767@char.us.oracle.com>

On Wed, Sep 23, 2020 at 04:09:30PM -0400, Konrad Rzeszutek Wilk wrote:
> On Tue, Sep 22, 2020 at 09:01:25AM +0200, SeongJae Park wrote:
> > From: SeongJae Park <sjpark@amazon.de>
> > 
> > Persistent grants feature provides high scalability.  On some small
> > systems, however, it could incur data copy overhead[1] and thus it is
> > required to be disabled.  But, there is no option to disable it.  For
> > the reason, this commit adds a module parameter for disabling of the
> > feature.
> 
> Would it be better suited to have it per guest?

I think having a per-backend policy that could be specified at the
toolstack level would be nice, but I see that as a further
improvement.

Having a global backend domain policy of whether persistent grants are
enabled or not seems desirable, and if someone wants even more fine
grained control this change is AFAICT not incompatible with a
per-backend option anyway.

Roger.

  parent reply	other threads:[~2020-09-24 10:13 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-22  7:01 [PATCH] xen-blkback: add a parameter for disabling of persistent grants SeongJae Park
2020-09-22  7:18 ` Jürgen Groß
2020-09-22  7:24   ` SeongJae Park
2020-09-22  7:32 ` Roger Pau Monné
2020-09-22  7:57   ` SeongJae Park
2020-09-23 20:09 ` Konrad Rzeszutek Wilk
2020-09-24  6:26   ` SeongJae Park
2020-09-24 10:13   ` Roger Pau Monné [this message]
2020-09-24 10:27     ` SeongJae Park
2020-09-24 10:47       ` Roger Pau Monné
2020-09-24 15:59         ` Konrad Rzeszutek Wilk

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