Re: [External] Re: [PATCH v9 3/5] migration: Add migration parameters for QATzip

[Yichen Wang]

On Wed, Sep 4, 2024 at 11:11 PM Prasad Pandit <ppandit@redhat.com> wrote:
>
> On Sat, 31 Aug 2024 at 04:58, Yichen Wang <yichen.wang@bytedance.com> wrote:
> > +/*
> > + * 1: best speed, ... 9: best compress ratio
> > + * There is some nuance here. Refer to QATzip documentation to understand
> > + * the mapping of QATzip levels to standard deflate levels.
> > + */
> > +#define DEFAULT_MIGRATE_MULTIFD_QATZIP_LEVEL 1
> > +
> ...
> > +# @multifd-qatzip-level: Set the compression level to be used in live
> > +#     migration. The level is an integer between 1 and 9, where 1 means
> > +#     the best compression speed, and 9 means the best compression
> > +#     ratio which will consume more CPU. Defaults to 1.  (Since 9.2)
> > +#
>
> * Should the default compression level be at the median of 1 - 9 => 5
> or 6 ? A compression method (QATzip) choosing speed (1) over
> compression as default seems contradictory.

This is being discussed on Patch V2,
https://lore.kernel.org/all/20240326224221.3623014-3-bryan.zhang@bytedance.com/.
The conclusion of the discussion with Intel is to keep 1 as the
default level.

>
> Otherwise:
> Reviewed-by: Prasad Pandit <pjp@fedoraproject.org>
>
> Thank you.
> ---
>   - Prasad
>