diff options
Diffstat (limited to 'drivers/block/xen-blkback/xenbus.c')
| -rw-r--r-- | drivers/block/xen-blkback/xenbus.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 4c5d99f87813..55960190b774 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -859,6 +859,26 @@ static void frontend_changed(struct xenbus_device *dev, } +/* Once a memory pressure is detected, squeeze free page pools for a while. */ +static unsigned int buffer_squeeze_duration_ms = 10; +module_param_named(buffer_squeeze_duration_ms, + buffer_squeeze_duration_ms, int, 0644); +MODULE_PARM_DESC(buffer_squeeze_duration_ms, +"Duration in ms to squeeze pages buffer when a memory pressure is detected"); + +/* + * Callback received when the memory pressure is detected. + */ +static void reclaim_memory(struct xenbus_device *dev) +{ + struct backend_info *be = dev_get_drvdata(&dev->dev); + + if (!be) + return; + be->blkif->buffer_squeeze_end = jiffies + + msecs_to_jiffies(buffer_squeeze_duration_ms); +} + /* ** Connection ** */ @@ -1152,6 +1172,7 @@ static struct xenbus_driver xen_blkbk_driver = { .remove = xen_blkbk_remove, .otherend_changed = frontend_changed, .allow_rebind = true, + .reclaim_memory = reclaim_memory, }; int xen_blkif_xenbus_init(void) |