diff options
Diffstat (limited to 'drivers/xen/xen-selfballoon.c')
| -rw-r--r-- | drivers/xen/xen-selfballoon.c | 88 |
1 files changed, 64 insertions, 24 deletions
diff --git a/drivers/xen/xen-selfballoon.c b/drivers/xen/xen-selfballoon.c index f70984a892a..3b2bffde534 100644 --- a/drivers/xen/xen-selfballoon.c +++ b/drivers/xen/xen-selfballoon.c @@ -64,6 +64,8 @@ * */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/kernel.h> #include <linux/bootmem.h> #include <linux/swap.h> @@ -168,11 +170,13 @@ static void frontswap_selfshrink(void) tgt_frontswap_pages = cur_frontswap_pages - (cur_frontswap_pages / frontswap_hysteresis); frontswap_shrink(tgt_frontswap_pages); + frontswap_inertia_counter = frontswap_inertia; } #endif /* CONFIG_FRONTSWAP */ #define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT)) +#define PAGES2MB(pages) ((pages) >> (20 - PAGE_SHIFT)) /* * Use current balloon size, the goal (vm_committed_as), and hysteresis @@ -263,8 +267,10 @@ static ssize_t store_selfballooning(struct device *dev, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &tmp); - if (err || ((tmp != 0) && (tmp != 1))) + err = kstrtoul(buf, 10, &tmp); + if (err) + return err; + if ((tmp != 0) && (tmp != 1)) return -EINVAL; xen_selfballooning_enabled = !!tmp; @@ -290,8 +296,10 @@ static ssize_t store_selfballoon_interval(struct device *dev, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); - if (err || val == 0) + err = kstrtoul(buf, 10, &val); + if (err) + return err; + if (val == 0) return -EINVAL; selfballoon_interval = val; return count; @@ -312,8 +320,10 @@ static ssize_t store_selfballoon_downhys(struct device *dev, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); - if (err || val == 0) + err = kstrtoul(buf, 10, &val); + if (err) + return err; + if (val == 0) return -EINVAL; selfballoon_downhysteresis = val; return count; @@ -335,8 +345,10 @@ static ssize_t store_selfballoon_uphys(struct device *dev, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); - if (err || val == 0) + err = kstrtoul(buf, 10, &val); + if (err) + return err; + if (val == 0) return -EINVAL; selfballoon_uphysteresis = val; return count; @@ -358,8 +370,10 @@ static ssize_t store_selfballoon_min_usable_mb(struct device *dev, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); - if (err || val == 0) + err = kstrtoul(buf, 10, &val); + if (err) + return err; + if (val == 0) return -EINVAL; selfballoon_min_usable_mb = val; return count; @@ -382,8 +396,10 @@ static ssize_t store_selfballoon_reserved_mb(struct device *dev, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); - if (err || val == 0) + err = kstrtoul(buf, 10, &val); + if (err) + return err; + if (val == 0) return -EINVAL; selfballoon_reserved_mb = val; return count; @@ -408,8 +424,10 @@ static ssize_t store_frontswap_selfshrinking(struct device *dev, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &tmp); - if (err || ((tmp != 0) && (tmp != 1))) + err = kstrtoul(buf, 10, &tmp); + if (err) + return err; + if ((tmp != 0) && (tmp != 1)) return -EINVAL; frontswap_selfshrinking = !!tmp; if (!was_enabled && !xen_selfballooning_enabled && @@ -435,8 +453,10 @@ static ssize_t store_frontswap_inertia(struct device *dev, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); - if (err || val == 0) + err = kstrtoul(buf, 10, &val); + if (err) + return err; + if (val == 0) return -EINVAL; frontswap_inertia = val; frontswap_inertia_counter = val; @@ -458,8 +478,10 @@ static ssize_t store_frontswap_hysteresis(struct device *dev, if (!capable(CAP_SYS_ADMIN)) return -EPERM; - err = strict_strtoul(buf, 10, &val); - if (err || val == 0) + err = kstrtoul(buf, 10, &val); + if (err) + return err; + if (val == 0) return -EINVAL; frontswap_hysteresis = val; return count; @@ -505,33 +527,51 @@ EXPORT_SYMBOL(register_xen_selfballooning); int xen_selfballoon_init(bool use_selfballooning, bool use_frontswap_selfshrink) { bool enable = false; + unsigned long reserve_pages; if (!xen_domain()) return -ENODEV; if (xen_initial_domain()) { - pr_info("xen/balloon: Xen selfballooning driver " - "disabled for domain0.\n"); + pr_info("Xen selfballooning driver disabled for domain0\n"); return -ENODEV; } xen_selfballooning_enabled = tmem_enabled && use_selfballooning; if (xen_selfballooning_enabled) { - pr_info("xen/balloon: Initializing Xen " - "selfballooning driver.\n"); + pr_info("Initializing Xen selfballooning driver\n"); enable = true; } #ifdef CONFIG_FRONTSWAP frontswap_selfshrinking = tmem_enabled && use_frontswap_selfshrink; if (frontswap_selfshrinking) { - pr_info("xen/balloon: Initializing frontswap " - "selfshrinking driver.\n"); + pr_info("Initializing frontswap selfshrinking driver\n"); enable = true; } #endif if (!enable) return -ENODEV; + /* + * Give selfballoon_reserved_mb a default value(10% of total ram pages) + * to make selfballoon not so aggressive. + * + * There are mainly two reasons: + * 1) The original goal_page didn't consider some pages used by kernel + * space, like slab pages and memory used by device drivers. + * + * 2) The balloon driver may not give back memory to guest OS fast + * enough when the workload suddenly aquries a lot of physical memory. + * + * In both cases, the guest OS will suffer from memory pressure and + * OOM killer may be triggered. + * By reserving extra 10% of total ram pages, we can keep the system + * much more reliably and response faster in some cases. + */ + if (!selfballoon_reserved_mb) { + reserve_pages = totalram_pages / 10; + selfballoon_reserved_mb = PAGES2MB(reserve_pages); + } schedule_delayed_work(&selfballoon_worker, selfballoon_interval * HZ); return 0; |