diff options
| -rw-r--r-- | drivers/xen/xen-selfballoon.c | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/drivers/xen/xen-selfballoon.c b/drivers/xen/xen-selfballoon.c index 146c9489701..7d041cb6da2 100644 --- a/drivers/xen/xen-selfballoon.c +++ b/drivers/xen/xen-selfballoon.c @@ -105,6 +105,12 @@ static unsigned int selfballoon_interval __read_mostly = 5; */ static unsigned int selfballoon_min_usable_mb; +/* + * Amount of RAM in MB to add to the target number of pages. + * Can be used to reserve some more room for caches and the like. + */ +static unsigned int selfballoon_reserved_mb; + static void selfballoon_process(struct work_struct *work); static DECLARE_DELAYED_WORK(selfballoon_worker, selfballoon_process); @@ -217,7 +223,8 @@ static void selfballoon_process(struct work_struct *work) cur_pages = totalram_pages; tgt_pages = cur_pages; /* default is no change */ goal_pages = percpu_counter_read_positive(&vm_committed_as) + - totalreserve_pages; + totalreserve_pages + + MB2PAGES(selfballoon_reserved_mb); #ifdef CONFIG_FRONTSWAP /* allow space for frontswap pages to be repatriated */ if (frontswap_selfshrinking && frontswap_enabled) @@ -397,6 +404,30 @@ static DEVICE_ATTR(selfballoon_min_usable_mb, S_IRUGO | S_IWUSR, show_selfballoon_min_usable_mb, store_selfballoon_min_usable_mb); +SELFBALLOON_SHOW(selfballoon_reserved_mb, "%d\n", + selfballoon_reserved_mb); + +static ssize_t store_selfballoon_reserved_mb(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count) +{ + unsigned long val; + int err; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + err = strict_strtoul(buf, 10, &val); + if (err || val == 0) + return -EINVAL; + selfballoon_reserved_mb = val; + return count; +} + +static DEVICE_ATTR(selfballoon_reserved_mb, S_IRUGO | S_IWUSR, + show_selfballoon_reserved_mb, + store_selfballoon_reserved_mb); + #ifdef CONFIG_FRONTSWAP SELFBALLOON_SHOW(frontswap_selfshrinking, "%d\n", frontswap_selfshrinking); @@ -480,6 +511,7 @@ static struct attribute *selfballoon_attrs[] = { &dev_attr_selfballoon_downhysteresis.attr, &dev_attr_selfballoon_uphysteresis.attr, &dev_attr_selfballoon_min_usable_mb.attr, + &dev_attr_selfballoon_reserved_mb.attr, #ifdef CONFIG_FRONTSWAP &dev_attr_frontswap_selfshrinking.attr, &dev_attr_frontswap_hysteresis.attr, |