On Thu, Oct 19, 2023 at 01:40:23PM +0200, Juan Quintela wrote: > Yuan Liu <yuan1....@intel.com> wrote: > > Hi, > > > > I am writing to submit a code change aimed at enhancing live migration > > acceleration by leveraging the compression capability of the Intel > > In-Memory Analytics Accelerator (IAA). > > > > Enabling compression functionality during the live migration process can > > enhance performance, thereby reducing downtime and network bandwidth > > requirements. However, this improvement comes at the cost of additional > > CPU resources, posing a challenge for cloud service providers in terms of > > resource allocation. To address this challenge, I have focused on offloading > > the compression overhead to the IAA hardware, resulting in performance > > gains. > > > > The implementation of the IAA (de)compression code is based on Intel Query > > Processing Library (QPL), an open-source software project designed for > > IAA high-level software programming. > > > > Best regards, > > Yuan Liu > > After reviewing the patches: > > - why are you doing this on top of old compression code, that is > obsolete, deprecated and buggy > > - why are you not doing it on top of multifd. > > You just need to add another compression method on top of multifd. > See how it was done for zstd:
I'm not sure that is ideal approach. IIUC, the IAA/QPL library is not defining a new compression format. Rather it is providing a hardware accelerator for 'deflate' format, as can be made compatible with zlib: https://intel.github.io/qpl/documentation/dev_guide_docs/c_use_cases/deflate/c_deflate_zlib_gzip.html#zlib-and-gzip-compatibility-reference-link With multifd we already have a 'zlib' compression format, and so this IAA/QPL logic would effectively just be a providing a second implementation of zlib. Given the use of a standard format, I would expect to be able to use software zlib on the src, mixed with IAA/QPL zlib on the target, or vica-verca. IOW, rather than defining a new compression format for this, I think we could look at a new migration parameter for "compression-accelerator": ["auto", "none", "qpl"] with 'auto' the default, such that we can automatically enable IAA/QPL when 'zlib' format is requested, if running on a suitable host. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
