diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index dbb68067ba4e..b11e1fd95ee5 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5480,6 +5480,13 @@ as generic guest with no PV drivers. Currently support XEN HVM, KVM, HYPER_V and VMWARE guest. + xen.balloon_boot_timeout= [XEN] + The time (in seconds) to wait before giving up to boot + in case initial ballooning fails to free enough memory. + Applies only when running as HVM or PVH guest and + started with less memory configured than allowed at + max. Default is 180. + xen.event_eoi_delay= [XEN] How long to delay EOI handling in case of event storms (jiffies). Default is 10. diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 07f362c63ae9..39bbb127852f 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -58,6 +58,7 @@ #include #include #include +#include #include #include @@ -75,6 +76,12 @@ #include #include +#undef MODULE_PARAM_PREFIX +#define MODULE_PARAM_PREFIX "xen." + +static uint __read_mostly balloon_boot_timeout = 180; +module_param(balloon_boot_timeout, uint, 0444); + static int xen_hotplug_unpopulated; #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG @@ -127,12 +134,12 @@ static struct ctl_table xen_root[] = { * BP_ECANCELED: error, balloon operation canceled. */ -enum bp_state { +static enum bp_state { BP_DONE, BP_WAIT, BP_EAGAIN, BP_ECANCELED -}; +} balloon_state = BP_DONE; /* Main waiting point for xen-balloon thread. */ static DECLARE_WAIT_QUEUE_HEAD(balloon_thread_wq); @@ -201,18 +208,15 @@ static struct page *balloon_next_page(struct page *page) return list_entry(next, struct page, lru); } -static enum bp_state update_schedule(enum bp_state state) +static void update_schedule(void) { - if (state == BP_WAIT) - return BP_WAIT; + if (balloon_state == BP_WAIT || balloon_state == BP_ECANCELED) + return; - if (state == BP_ECANCELED) - return BP_ECANCELED; - - if (state == BP_DONE) { + if (balloon_state == BP_DONE) { balloon_stats.schedule_delay = 1; balloon_stats.retry_count = 1; - return BP_DONE; + return; } ++balloon_stats.retry_count; @@ -221,7 +225,8 @@ static enum bp_state update_schedule(enum bp_state state) balloon_stats.retry_count > balloon_stats.max_retry_count) { balloon_stats.schedule_delay = 1; balloon_stats.retry_count = 1; - return BP_ECANCELED; + balloon_state = BP_ECANCELED; + return; } balloon_stats.schedule_delay <<= 1; @@ -229,7 +234,7 @@ static enum bp_state update_schedule(enum bp_state state) if (balloon_stats.schedule_delay > balloon_stats.max_schedule_delay) balloon_stats.schedule_delay = balloon_stats.max_schedule_delay; - return BP_EAGAIN; + balloon_state = BP_EAGAIN; } #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG @@ -511,9 +516,9 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) * Stop waiting if either state is BP_DONE and ballooning action is * needed, or if the credit has changed while state is not BP_DONE. */ -static bool balloon_thread_cond(enum bp_state state, long credit) +static bool balloon_thread_cond(long credit) { - if (state == BP_DONE) + if (balloon_state == BP_DONE) credit = 0; return current_credit() != credit || kthread_should_stop(); @@ -527,13 +532,12 @@ static bool balloon_thread_cond(enum bp_state state, long credit) */ static int balloon_thread(void *unused) { - enum bp_state state = BP_DONE; long credit; unsigned long timeout; set_freezable(); for (;;) { - switch (state) { + switch (balloon_state) { case BP_DONE: case BP_ECANCELED: timeout = 3600 * HZ; @@ -549,7 +553,7 @@ static int balloon_thread(void *unused) credit = current_credit(); wait_event_freezable_timeout(balloon_thread_wq, - balloon_thread_cond(state, credit), timeout); + balloon_thread_cond(credit), timeout); if (kthread_should_stop()) return 0; @@ -560,22 +564,23 @@ static int balloon_thread(void *unused) if (credit > 0) { if (balloon_is_inflated()) - state = increase_reservation(credit); + balloon_state = increase_reservation(credit); else - state = reserve_additional_memory(); + balloon_state = reserve_additional_memory(); } if (credit < 0) { long n_pages; n_pages = min(-credit, si_mem_available()); - state = decrease_reservation(n_pages, GFP_BALLOON); - if (state == BP_DONE && n_pages != -credit && + balloon_state = decrease_reservation(n_pages, + GFP_BALLOON); + if (balloon_state == BP_DONE && n_pages != -credit && n_pages < totalreserve_pages) - state = BP_EAGAIN; + balloon_state = BP_EAGAIN; } - state = update_schedule(state); + update_schedule(); mutex_unlock(&balloon_mutex); @@ -782,3 +787,38 @@ static int __init balloon_init(void) return 0; } subsys_initcall(balloon_init); + +static int __init balloon_wait_finish(void) +{ + long credit, last_credit = 0; + unsigned long last_changed = 0; + + if (!xen_domain()) + return -ENODEV; + + /* PV guests don't need to wait. */ + if (xen_pv_domain() || !current_credit()) + return 0; + + pr_notice("Waiting for initial ballooning down having finished.\n"); + + while ((credit = current_credit()) < 0) { + if (credit != last_credit) { + last_changed = jiffies; + last_credit = credit; + } + if (balloon_state == BP_ECANCELED) { + pr_warn_once("Initial ballooning failed, %ld pages need to be freed.\n", + -credit); + if (jiffies - last_changed >= HZ * balloon_boot_timeout) + panic("Initial ballooning failed!\n"); + } + + schedule_timeout_interruptible(HZ / 10); + } + + pr_notice("Initial ballooning down finished.\n"); + + return 0; +} +late_initcall_sync(balloon_wait_finish);