0001 What: /sys/module/xen_blkback/parameters/max_buffer_pages
0002 Date: March 2013
0003 KernelVersion: 3.11
0004 Contact: Roger Pau Monné <roger.pau@citrix.com>
0005 Description:
0006 Maximum number of free pages to keep in each block
0007 backend buffer.
0008
0009 What: /sys/module/xen_blkback/parameters/max_persistent_grants
0010 Date: March 2013
0011 KernelVersion: 3.11
0012 Contact: Roger Pau Monné <roger.pau@citrix.com>
0013 Description:
0014 Maximum number of grants to map persistently in
0015 blkback. If the frontend tries to use more than
0016 max_persistent_grants, the LRU kicks in and starts
0017 removing 5% of max_persistent_grants every 100ms.
0018
0019 What: /sys/module/xen_blkback/parameters/persistent_grant_unused_seconds
0020 Date: August 2018
0021 KernelVersion: 4.19
0022 Contact: Roger Pau Monné <roger.pau@citrix.com>
0023 Description:
0024 How long a persistent grant is allowed to remain
0025 allocated without being in use. The time is in
0026 seconds, 0 means indefinitely long.
0027 The default is 60 seconds.
0028
0029 What: /sys/module/xen_blkback/parameters/buffer_squeeze_duration_ms
0030 Date: December 2019
0031 KernelVersion: 5.6
0032 Contact: Maximilian Heyne <mheyne@amazon.de>
0033 Description:
0034 When memory pressure is reported to blkback this option
0035 controls the duration in milliseconds that blkback will not
0036 cache any page not backed by a grant mapping.
0037 The default is 10ms.
0038
0039 What: /sys/module/xen_blkback/parameters/feature_persistent
0040 Date: September 2020
0041 KernelVersion: 5.10
0042 Contact: Maximilian Heyne <mheyne@amazon.de>
0043 Description:
0044 Whether to enable the persistent grants feature or not. Note
0045 that this option only takes effect on newly connected backends.
0046 The default is Y (enable).
