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[v3,0/3] xen-blk(back|front): Let users disable persistent grants

Message ID 20200922141549.26154-1-sjpark@amazon.com (mailing list archive)
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Series xen-blk(back|front): Let users disable persistent grants | expand

Message

SeongJae Park Sept. 22, 2020, 2:15 p.m. UTC
From: SeongJae Park <sjpark@amazon.de>

Persistent grants feature provides high scalability.  On some small
systems, however, it could incur data copy overheads[1] and thus it is
required to be disabled.  But, there is no option to disable it.  For
the reason, this commit adds module parameters for disabling of the
feature.

[1] https://wiki.xen.org/wiki/Xen_4.3_Block_Protocol_Scalability

Baseline and Complete Git Trees
===============================

The patches are based on the v5.9-rc6.  You can also clone the complete
git tree:

    $ git clone git://github.com/sjp38/linux -b pgrants_disable_v3

The web is also available:
https://github.com/sjp38/linux/tree/pgrants_disable_v3

Patch History
=============

Changes from v2
(https://lore.kernel.org/linux-block/20200922105209.5284-1-sjpark@amazon.com/)
- Avoid race conditions (Roger Pau Monné)

Changes from v1
(https://lore.kernel.org/linux-block/20200922070125.27251-1-sjpark@amazon.com/)
- use 'bool' parameter type (Jürgen Groß)
- Let blkfront can also disable the feature from its side
  (Roger Pau Monné)
- Avoid unnecessary xenbus_printf (Roger Pau Monné)
- Update frontend parameter doc


SeongJae Park (3):
  xen-blkback: add a parameter for disabling of persistent grants
  xen-blkfront: add a parameter for disabling of persistent grants
  xen-blkfront: Apply changed parameter name to the document

 .../ABI/testing/sysfs-driver-xen-blkback      |  9 ++++++++
 .../ABI/testing/sysfs-driver-xen-blkfront     | 11 +++++++++-
 drivers/block/xen-blkback/xenbus.c            | 22 ++++++++++++++-----
 drivers/block/xen-blkfront.c                  | 20 ++++++++++++-----
 4 files changed, 50 insertions(+), 12 deletions(-)

Comments

Roger Pau Monné Sept. 22, 2020, 2:45 p.m. UTC | #1
On Tue, Sep 22, 2020 at 04:15:46PM +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 overheads[1] and thus it is
> required to be disabled.  But, there is no option to disable it.  For
> the reason, this commit adds module parameters for disabling of the
> feature.

With the changes requested by Jürgen you can add my:

Acked-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks, Roger.
SeongJae Park Sept. 22, 2020, 2:52 p.m. UTC | #2
On Tue, 22 Sep 2020 16:45:56 +0200 "Roger Pau Monné" <roger.pau@citrix.com> wrote:

> On Tue, Sep 22, 2020 at 04:15:46PM +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 overheads[1] and thus it is
> > required to be disabled.  But, there is no option to disable it.  For
> > the reason, this commit adds module parameters for disabling of the
> > feature.
> 
> With the changes requested by Jürgen you can add my:
> 
> Acked-by: Roger Pau Monné <roger.pau@citrix.com>

Thank you for your kind and helpful reviews!


Thanks,
SeongJae Park