[Cluster-devel] [PATCH 0/2] Improve throughput through rgrp sharing (v2)

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,


On 08/05/18 21:04, Bob Peterson wrote:
> Hi,
>
> On 18 April, I posted v1 of this patch set. The idea is to allow multiple
> processes on a node to share a glock that's held exclusively in order to
> improve performance. Sharing rgrps allows for better throughput by
> reducing contention.
>
> Version 1 implemented this by introducing a new glock mode for sharing
> glocks. Steve Whitehouse suggested we didn't need a new mode: we can
> accomplish the same thing just by having a new glock flag, which also
> makes the patch more simple.
>
> This version 2 patch set implements Steve's suggestion.
>
> The first patch introduces the new glock flag. The second patch puts
> it into use for rgrp sharing. Exclusive access to the rgrp is implemented
> through an rwsem.
>
> Performance testing using iozone looks even better than version 1.
Sounds really good! We should make sure that we give this a really good 
round of testing and it would be nice to see some details of the 
performance improvements. Overall though, that's an excellent result :-)

Steve.

> ---
> Bob Peterson (2):
>    GFS2: Introduce GLF_EX_SHARING bit: local EX sharing
>    GFS2: Take advantage of new EXSH glock mode for rgrps
>
>   fs/gfs2/bmap.c   |   2 +-
>   fs/gfs2/dir.c    |   2 +-
>   fs/gfs2/glock.c  |  23 ++++++++++---
>   fs/gfs2/glock.h  |   4 +++
>   fs/gfs2/incore.h |   2 ++
>   fs/gfs2/inode.c  |   7 ++--
>   fs/gfs2/rgrp.c   | 103 ++++++++++++++++++++++++++++++++++++++++++++++---------
>   fs/gfs2/rgrp.h   |   2 +-
>   fs/gfs2/super.c  |   8 +++--
>   fs/gfs2/xattr.c  |   8 +++--
>   10 files changed, 129 insertions(+), 32 deletions(-)
>