1 What: /sys/module/xen_blkback/parame 1 What: /sys/module/xen_blkback/parameters/max_buffer_pages
2 Date: March 2013 2 Date: March 2013
3 KernelVersion: 3.11 3 KernelVersion: 3.11
4 Contact: Roger Pau Monné <roger.pau@cit 4 Contact: Roger Pau Monné <roger.pau@citrix.com>
5 Description: 5 Description:
6 Maximum number of free pages t 6 Maximum number of free pages to keep in each block
7 backend buffer. 7 backend buffer.
8 8
9 What: /sys/module/xen_blkback/parame 9 What: /sys/module/xen_blkback/parameters/max_persistent_grants
10 Date: March 2013 10 Date: March 2013
11 KernelVersion: 3.11 11 KernelVersion: 3.11
12 Contact: Roger Pau Monné <roger.pau@cit 12 Contact: Roger Pau Monné <roger.pau@citrix.com>
13 Description: 13 Description:
14 Maximum number of grants to ma 14 Maximum number of grants to map persistently in
15 blkback. If the frontend tries 15 blkback. If the frontend tries to use more than
16 max_persistent_grants, the LRU 16 max_persistent_grants, the LRU kicks in and starts
17 removing 5% of max_persistent_ 17 removing 5% of max_persistent_grants every 100ms.
18 18
19 What: /sys/module/xen_blkback/parame 19 What: /sys/module/xen_blkback/parameters/persistent_grant_unused_seconds
20 Date: August 2018 20 Date: August 2018
21 KernelVersion: 4.19 21 KernelVersion: 4.19
22 Contact: Roger Pau Monné <roger.pau@cit 22 Contact: Roger Pau Monné <roger.pau@citrix.com>
23 Description: 23 Description:
24 How long a persistent grant is 24 How long a persistent grant is allowed to remain
25 allocated without being in use 25 allocated without being in use. The time is in
26 seconds, 0 means indefinitely 26 seconds, 0 means indefinitely long.
27 The default is 60 seconds. 27 The default is 60 seconds.
28 28
29 What: /sys/module/xen_blkback/parame 29 What: /sys/module/xen_blkback/parameters/buffer_squeeze_duration_ms
30 Date: December 2019 30 Date: December 2019
31 KernelVersion: 5.6 31 KernelVersion: 5.6
32 Contact: Maximilian Heyne <mheyne@amazon !! 32 Contact: SeongJae Park <sj@kernel.org>
33 Description: 33 Description:
34 When memory pressure is report 34 When memory pressure is reported to blkback this option
35 controls the duration in milli 35 controls the duration in milliseconds that blkback will not
36 cache any page not backed by a 36 cache any page not backed by a grant mapping.
37 The default is 10ms. 37 The default is 10ms.
38 38
39 What: /sys/module/xen_blkback/parame 39 What: /sys/module/xen_blkback/parameters/feature_persistent
40 Date: September 2020 40 Date: September 2020
41 KernelVersion: 5.10 41 KernelVersion: 5.10
42 Contact: Maximilian Heyne <mheyne@amazon !! 42 Contact: SeongJae Park <sj@kernel.org>
43 Description: 43 Description:
44 Whether to enable the persiste 44 Whether to enable the persistent grants feature or not. Note
45 that this option only takes ef !! 45 that this option only takes effect on newly created backends.
46 The default is Y (enable). 46 The default is Y (enable).
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