18c2ecf20Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/max_buffer_pages
28c2ecf20Sopenharmony_ciDate:           March 2013
38c2ecf20Sopenharmony_ciKernelVersion:  3.11
48c2ecf20Sopenharmony_ciContact:        Roger Pau Monné <roger.pau@citrix.com>
58c2ecf20Sopenharmony_ciDescription:
68c2ecf20Sopenharmony_ci                Maximum number of free pages to keep in each block
78c2ecf20Sopenharmony_ci                backend buffer.
88c2ecf20Sopenharmony_ci
98c2ecf20Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/max_persistent_grants
108c2ecf20Sopenharmony_ciDate:           March 2013
118c2ecf20Sopenharmony_ciKernelVersion:  3.11
128c2ecf20Sopenharmony_ciContact:        Roger Pau Monné <roger.pau@citrix.com>
138c2ecf20Sopenharmony_ciDescription:
148c2ecf20Sopenharmony_ci                Maximum number of grants to map persistently in
158c2ecf20Sopenharmony_ci                blkback. If the frontend tries to use more than
168c2ecf20Sopenharmony_ci                max_persistent_grants, the LRU kicks in and starts
178c2ecf20Sopenharmony_ci                removing 5% of max_persistent_grants every 100ms.
188c2ecf20Sopenharmony_ci
198c2ecf20Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/persistent_grant_unused_seconds
208c2ecf20Sopenharmony_ciDate:           August 2018
218c2ecf20Sopenharmony_ciKernelVersion:  4.19
228c2ecf20Sopenharmony_ciContact:        Roger Pau Monné <roger.pau@citrix.com>
238c2ecf20Sopenharmony_ciDescription:
248c2ecf20Sopenharmony_ci                How long a persistent grant is allowed to remain
258c2ecf20Sopenharmony_ci                allocated without being in use. The time is in
268c2ecf20Sopenharmony_ci                seconds, 0 means indefinitely long.
278c2ecf20Sopenharmony_ci                The default is 60 seconds.
288c2ecf20Sopenharmony_ci
298c2ecf20Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/buffer_squeeze_duration_ms
308c2ecf20Sopenharmony_ciDate:           December 2019
318c2ecf20Sopenharmony_ciKernelVersion:  5.6
328c2ecf20Sopenharmony_ciContact:        SeongJae Park <sjpark@amazon.de>
338c2ecf20Sopenharmony_ciDescription:
348c2ecf20Sopenharmony_ci                When memory pressure is reported to blkback this option
358c2ecf20Sopenharmony_ci                controls the duration in milliseconds that blkback will not
368c2ecf20Sopenharmony_ci                cache any page not backed by a grant mapping.
378c2ecf20Sopenharmony_ci                The default is 10ms.
388c2ecf20Sopenharmony_ci
398c2ecf20Sopenharmony_ciWhat:           /sys/module/xen_blkback/parameters/feature_persistent
408c2ecf20Sopenharmony_ciDate:           September 2020
418c2ecf20Sopenharmony_ciKernelVersion:  5.10
428c2ecf20Sopenharmony_ciContact:        SeongJae Park <sjpark@amazon.de>
438c2ecf20Sopenharmony_ciDescription:
448c2ecf20Sopenharmony_ci                Whether to enable the persistent grants feature or not.  Note
458c2ecf20Sopenharmony_ci                that this option only takes effect on newly connected backends.
468c2ecf20Sopenharmony_ci                The default is Y (enable).
47