Re: [PATCH vhost v2 0/7] vdpa/mlx5: Optimze MKEY operations

From: Eugenio Perez Martin
Date: Wed Sep 11 2024 - 04:03:13 EST


On Mon, Sep 9, 2024 at 11:30 AM Dragos Tatulea <dtatulea@xxxxxxxxxx> wrote:
>
>
>
> On 30.08.24 12:58, Dragos Tatulea wrote:
> > This series improves the time of .set_map() operations by parallelizing
> > the MKEY creation and deletion for direct MKEYs. Looking at the top
> > level MKEY creation/deletion functions, the following improvement can be
> > seen:
> >
> > |-------------------+-------------|
> > | operation | improvement |
> > |-------------------+-------------|
> > | create_user_mr() | 3-5x |
> > | destroy_user_mr() | 8x |
> > |-------------------+-------------|
> >
> > The last part of the series introduces lazy MKEY deletion which
> > postpones the MKEY deletion to a later point in a workqueue.
> >
> > As this series and the previous ones were targeting live migration,
> > we can also observe improvements on this front:
> >
> > |-------------------+------------------+------------------|
> > | Stage | Downtime #1 (ms) | Downtime #2 (ms) |
> > |-------------------+------------------+------------------|
> > | Baseline | 3140 | 3630 |
> > | Parallel MKEY ops | 1200 | 2000 |
> > | Deferred deletion | 1014 | 1253 |
> > |-------------------+------------------+------------------|
> >
> > Test configuration: 256 GB VM, 32 CPUs x 2 threads per core, 4 x mlx5
> > vDPA devices x 32 VQs (16 VQPs)
> >
> > This series must be applied on top of the parallel VQ suspend/resume
> > series [0].
> >
> > [0] https://lore.kernel.org/all/20240816090159.1967650-1-dtatulea@xxxxxxxxxx/
> >
> > ---
> > v2:
> > - Swapped flex array usage for plain zero length array in first patch.
> > - Updated code to use Scope-Based Cleanup Helpers where appropriate
> > (only second patch).
> > - Added macro define for MTT alignment in first patch.
> > - Improved commit messages/comments based on review comments.
> > - Removed extra newlines.
> Gentle ping for the remaining patches in v2.
>

Same here, this series is already in MST's branch:
https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git/commit/?h=vhost&id=d424b079e243128383e88bee79f143ff30b4ec62