diff options
Diffstat (limited to 'mm/page_reporting.c')
| -rw-r--r-- | mm/page_reporting.c | 71 |
1 files changed, 62 insertions, 9 deletions
diff --git a/mm/page_reporting.c b/mm/page_reporting.c index 3bbd471cfc81..e4c428e61d8c 100644 --- a/mm/page_reporting.c +++ b/mm/page_reporting.c @@ -4,12 +4,49 @@ #include <linux/page_reporting.h> #include <linux/gfp.h> #include <linux/export.h> +#include <linux/module.h> #include <linux/delay.h> #include <linux/scatterlist.h> #include "page_reporting.h" #include "internal.h" +/* Initialize to an unsupported value */ +unsigned int page_reporting_order = -1; + +static int page_order_update_notify(const char *val, const struct kernel_param *kp) +{ + /* + * If param is set beyond this limit, order is set to default + * pageblock_order value + */ + return param_set_uint_minmax(val, kp, 0, MAX_PAGE_ORDER); +} + +static const struct kernel_param_ops page_reporting_param_ops = { + .set = &page_order_update_notify, + /* + * For the get op, use param_get_int instead of param_get_uint. + * This is to make sure that when unset the initialized value of + * -1 is shown correctly + */ + .get = ¶m_get_int, +}; + +module_param_cb(page_reporting_order, &page_reporting_param_ops, + &page_reporting_order, 0644); +MODULE_PARM_DESC(page_reporting_order, "Set page reporting order"); + +/* + * This symbol is also a kernel parameter. Export the page_reporting_order + * symbol so that other drivers can access it to control order values without + * having to introduce another configurable parameter. Only one driver can + * register with the page_reporting driver for the service, so we have just + * one control parameter for the use case(which can be accessed in both + * drivers) + */ +EXPORT_SYMBOL_GPL(page_reporting_order); + #define PAGE_REPORTING_DELAY (2 * HZ) static struct page_reporting_dev_info __rcu *pr_dev_info __read_mostly; @@ -31,8 +68,8 @@ __page_reporting_request(struct page_reporting_dev_info *prdev) return; /* - * If reporting is already active there is nothing we need to do. - * Test against 0 as that represents PAGE_REPORTING_IDLE. + * If reporting is already active there is nothing we need to do. + * Test against 0 as that represents PAGE_REPORTING_IDLE. */ state = atomic_xchg(&prdev->state, PAGE_REPORTING_REQUESTED); if (state != PAGE_REPORTING_IDLE) @@ -92,7 +129,7 @@ page_reporting_drain(struct page_reporting_dev_info *prdev, * report on the new larger page when we make our way * up to that higher order. */ - if (PageBuddy(page) && page_order(page) == order) + if (PageBuddy(page) && buddy_order(page) == order) __SetPageReported(page); } while ((sg = sg_next(sg))); @@ -178,7 +215,7 @@ page_reporting_cycle(struct page_reporting_dev_info *prdev, struct zone *zone, * the new head of the free list before we release the * zone lock. */ - if (&page->lru != list && !list_is_first(&page->lru, list)) + if (!list_is_first(&page->lru, list)) list_rotate_to_front(&page->lru, list); /* release lock before waiting on report processing */ @@ -211,7 +248,7 @@ page_reporting_cycle(struct page_reporting_dev_info *prdev, struct zone *zone, } /* Rotate any leftover pages to the head of the freelist */ - if (&next->lru != list && !list_is_first(&next->lru, list)) + if (!list_entry_is_head(next, list, lru) && !list_is_first(&next->lru, list)) list_rotate_to_front(&next->lru, list); spin_unlock_irq(&zone->lock); @@ -229,7 +266,7 @@ page_reporting_process_zone(struct page_reporting_dev_info *prdev, /* Generate minimum watermark to be able to guarantee progress */ watermark = low_wmark_pages(zone) + - (PAGE_REPORTING_CAPACITY << PAGE_REPORTING_MIN_ORDER); + (PAGE_REPORTING_CAPACITY << page_reporting_order); /* * Cancel request if insufficient free memory or if we failed @@ -239,7 +276,7 @@ page_reporting_process_zone(struct page_reporting_dev_info *prdev, return err; /* Process each free list starting from lowest order/mt */ - for (order = PAGE_REPORTING_MIN_ORDER; order < MAX_ORDER; order++) { + for (order = page_reporting_order; order < NR_PAGE_ORDERS; order++) { for (mt = 0; mt < MIGRATE_TYPES; mt++) { /* We do not pull pages from the isolate free list */ if (is_migrate_isolate(mt)) @@ -319,11 +356,26 @@ int page_reporting_register(struct page_reporting_dev_info *prdev) mutex_lock(&page_reporting_mutex); /* nothing to do if already in use */ - if (rcu_access_pointer(pr_dev_info)) { + if (rcu_dereference_protected(pr_dev_info, + lockdep_is_held(&page_reporting_mutex))) { err = -EBUSY; goto err_out; } + /* + * If the page_reporting_order value is not set, we check if + * an order is provided from the driver that is performing the + * registration. If that is not provided either, we default to + * pageblock_order. + */ + + if (page_reporting_order == -1) { + if (prdev->order > 0 && prdev->order <= MAX_PAGE_ORDER) + page_reporting_order = prdev->order; + else + page_reporting_order = pageblock_order; + } + /* initialize state and work structures */ atomic_set(&prdev->state, PAGE_REPORTING_IDLE); INIT_DELAYED_WORK(&prdev->work, &page_reporting_process); @@ -350,7 +402,8 @@ void page_reporting_unregister(struct page_reporting_dev_info *prdev) { mutex_lock(&page_reporting_mutex); - if (rcu_access_pointer(pr_dev_info) == prdev) { + if (prdev == rcu_dereference_protected(pr_dev_info, + lockdep_is_held(&page_reporting_mutex))) { /* Disable page reporting notification */ RCU_INIT_POINTER(pr_dev_info, NULL); synchronize_rcu(); |