From: Gavin Shan <gshan@xxxxxxxxxx> Subject: mm/page_reporting: export reporting order as module parameter The macro PAGE_REPORTING_MIN_ORDER is defined as the page reporting threshold. It can't be adjusted at runtime. This introduces a variable (@page_reporting_order) to replace the marcro (PAGE_REPORTING_MIN_ORDER). MAX_ORDER is assigned to it initially, meaning the page reporting is disabled. It will be specified by driver if valid one is provided. Otherwise, it will fall back to @pageblock_order. It's also exported so that the page reporting order can be adjusted at runtime. Link: https://lkml.kernel.org/r/20210625014710.42954-3-gshan@xxxxxxxxxx Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx> Suggested-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Alexander Duyck <alexanderduyck@xxxxxx> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/admin-guide/kernel-parameters.txt | 6 ++++++ mm/page_reporting.c | 9 +++++++-- mm/page_reporting.h | 5 ++--- 3 files changed, 15 insertions(+), 5 deletions(-) --- a/Documentation/admin-guide/kernel-parameters.txt~mm-page_reporting-export-reporting-order-as-module-parameter +++ a/Documentation/admin-guide/kernel-parameters.txt @@ -3566,6 +3566,12 @@ off: turn off poisoning (default) on: turn on poisoning + page_reporting.page_reporting_order= + [KNL] Minimal page reporting order + Format: <integer> + Adjust the minimal page reporting order. The page + reporting is disabled when it exceeds (MAX_ORDER-1). + panic= [KNL] Kernel behaviour on panic: delay <timeout> timeout > 0: seconds before rebooting timeout = 0: wait forever --- a/mm/page_reporting.c~mm-page_reporting-export-reporting-order-as-module-parameter +++ a/mm/page_reporting.c @@ -4,12 +4,17 @@ #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" +unsigned int page_reporting_order = MAX_ORDER; +module_param(page_reporting_order, uint, 0644); +MODULE_PARM_DESC(page_reporting_order, "Set page reporting order"); + #define PAGE_REPORTING_DELAY (2 * HZ) static struct page_reporting_dev_info __rcu *pr_dev_info __read_mostly; @@ -229,7 +234,7 @@ page_reporting_process_zone(struct page_ /* 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 +244,7 @@ page_reporting_process_zone(struct page_ 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 < MAX_ORDER; order++) { for (mt = 0; mt < MIGRATE_TYPES; mt++) { /* We do not pull pages from the isolate free list */ if (is_migrate_isolate(mt)) --- a/mm/page_reporting.h~mm-page_reporting-export-reporting-order-as-module-parameter +++ a/mm/page_reporting.h @@ -10,10 +10,9 @@ #include <linux/pgtable.h> #include <linux/scatterlist.h> -#define PAGE_REPORTING_MIN_ORDER pageblock_order - #ifdef CONFIG_PAGE_REPORTING DECLARE_STATIC_KEY_FALSE(page_reporting_enabled); +extern unsigned int page_reporting_order; void __page_reporting_notify(void); static inline bool page_reported(struct page *page) @@ -38,7 +37,7 @@ static inline void page_reporting_notify return; /* Determine if we have crossed reporting threshold */ - if (order < PAGE_REPORTING_MIN_ORDER) + if (order < page_reporting_order) return; /* This will add a few cycles, but should be called infrequently */ _
