From 973e5405f2f67ddbb2bf07b3ffc71908a37fea8e Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 13 Aug 2018 16:01:10 +0200 Subject: xen/blkback: don't keep persistent grants too long MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Persistent grants are allocated until a threshold per ring is being reached. Those grants won't be freed until the ring is being destroyed meaning there will be resources kept busy which might no longer be used. Instead of freeing only persistent grants until the threshold is reached add a timestamp and remove all persistent grants not having been in use for a minute. Signed-off-by: Juergen Gross Reviewed-by: Roger Pau Monné Signed-off-by: Konrad Rzeszutek Wilk --- Documentation/ABI/testing/sysfs-driver-xen-blkback | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback index 8bb43b66eb55..4e7babb3ba1f 100644 --- a/Documentation/ABI/testing/sysfs-driver-xen-blkback +++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback @@ -15,3 +15,13 @@ Description: blkback. If the frontend tries to use more than max_persistent_grants, the LRU kicks in and starts removing 5% of max_persistent_grants every 100ms. + +What: /sys/module/xen_blkback/parameters/persistent_grant_unused_seconds +Date: August 2018 +KernelVersion: 4.19 +Contact: Roger Pau Monné +Description: + How long a persistent grant is allowed to remain + allocated without being in use. The time is in + seconds, 0 means indefinitely long. + The default is 60 seconds. -- cgit v1.2.3-59-g8ed1b