diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_reporting.c | 50 |
1 files changed, 45 insertions, 5 deletions
diff --git a/mm/page_reporting.c b/mm/page_reporting.c index 382958eef8a9..79a8554f024c 100644 --- a/mm/page_reporting.c +++ b/mm/page_reporting.c @@ -11,10 +11,42 @@ #include "page_reporting.h" #include "internal.h" -unsigned int page_reporting_order = MAX_ORDER; -module_param(page_reporting_order, uint, 0644); +/* 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_ORDER-1); +} + +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; @@ -330,10 +362,18 @@ int page_reporting_register(struct page_reporting_dev_info *prdev) } /* - * Update the page reporting order if it's specified by driver. - * Otherwise, it falls back to @pageblock_order. + * 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. */ - page_reporting_order = prdev->order ? : pageblock_order; + + if (page_reporting_order == -1) { + if (prdev->order > 0 && prdev->order <= MAX_ORDER) + page_reporting_order = prdev->order; + else + page_reporting_order = pageblock_order; + } /* initialize state and work structures */ atomic_set(&prdev->state, PAGE_REPORTING_IDLE); |