162306a36Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/max_buffer_pages
262306a36Sopenharmony_ciDate:           March 2013
362306a36Sopenharmony_ciKernelVersion:  3.11
462306a36Sopenharmony_ciContact:        Roger Pau Monné <roger.pau@citrix.com>
562306a36Sopenharmony_ciDescription:
662306a36Sopenharmony_ci                Maximum number of free pages to keep in each block
762306a36Sopenharmony_ci                backend buffer.
862306a36Sopenharmony_ci
962306a36Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/max_persistent_grants
1062306a36Sopenharmony_ciDate:           March 2013
1162306a36Sopenharmony_ciKernelVersion:  3.11
1262306a36Sopenharmony_ciContact:        Roger Pau Monné <roger.pau@citrix.com>
1362306a36Sopenharmony_ciDescription:
1462306a36Sopenharmony_ci                Maximum number of grants to map persistently in
1562306a36Sopenharmony_ci                blkback. If the frontend tries to use more than
1662306a36Sopenharmony_ci                max_persistent_grants, the LRU kicks in and starts
1762306a36Sopenharmony_ci                removing 5% of max_persistent_grants every 100ms.
1862306a36Sopenharmony_ci
1962306a36Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/persistent_grant_unused_seconds
2062306a36Sopenharmony_ciDate:           August 2018
2162306a36Sopenharmony_ciKernelVersion:  4.19
2262306a36Sopenharmony_ciContact:        Roger Pau Monné <roger.pau@citrix.com>
2362306a36Sopenharmony_ciDescription:
2462306a36Sopenharmony_ci                How long a persistent grant is allowed to remain
2562306a36Sopenharmony_ci                allocated without being in use. The time is in
2662306a36Sopenharmony_ci                seconds, 0 means indefinitely long.
2762306a36Sopenharmony_ci                The default is 60 seconds.
2862306a36Sopenharmony_ci
2962306a36Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/buffer_squeeze_duration_ms
3062306a36Sopenharmony_ciDate:           December 2019
3162306a36Sopenharmony_ciKernelVersion:  5.6
3262306a36Sopenharmony_ciContact:        Maximilian Heyne <mheyne@amazon.de>
3362306a36Sopenharmony_ciDescription:
3462306a36Sopenharmony_ci                When memory pressure is reported to blkback this option
3562306a36Sopenharmony_ci                controls the duration in milliseconds that blkback will not
3662306a36Sopenharmony_ci                cache any page not backed by a grant mapping.
3762306a36Sopenharmony_ci                The default is 10ms.
3862306a36Sopenharmony_ci
3962306a36Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/feature_persistent
4062306a36Sopenharmony_ciDate:           September 2020
4162306a36Sopenharmony_ciKernelVersion:  5.10
4262306a36Sopenharmony_ciContact:        Maximilian Heyne <mheyne@amazon.de>
4362306a36Sopenharmony_ciDescription:
4462306a36Sopenharmony_ci                Whether to enable the persistent grants feature or not.  Note
4562306a36Sopenharmony_ci                that this option only takes effect on newly connected backends.
4662306a36Sopenharmony_ci                The default is Y (enable).
47