Patch adds a defer_meminit=[enable|disable] kernel command line option. Default is controlled by Kconfig.
Signed-off-by: Mel Gorman <[email protected]> --- Documentation/kernel-parameters.txt | 8 ++++++++ include/linux/mmzone.h | 14 ++++++++++++++ init/main.c | 1 + mm/Kconfig | 10 ++++++++++ mm/page_alloc.c | 24 ++++++++++++++++++++++++ 5 files changed, 57 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index bfcb1a62a7b4..867338fc5941 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -807,6 +807,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. debug_objects [KNL] Enable object debugging + defer_meminit= [KNL,X86] Enable or disable deferred memory init. + Large machine may take a long time to initialise + memory management structures. If this is enabled + then memory initialisation is deferred to kswapd + and each memory node is initialised in parallel. + In very early boot, there will be less memory that + will rapidly increase while it is initialised. + no_debug_objects [KNL] Disable object debugging diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 20c2da89a14d..1275f9a8cb42 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -823,6 +823,20 @@ static inline struct zone *lruvec_zone(struct lruvec *lruvec) #endif } + +#ifdef CONFIG_DEFERRED_MEM_INIT +extern bool deferred_mem_init_enabled; +static inline void setup_deferred_meminit(void) +{ + if (IS_ENABLED(CONFIG_DEFERRED_MEM_INIT_DEFAULT_ENABLED)) + deferred_mem_init_enabled = true; +} +#else +static inline void setup_deferred_meminit(void) +{ +} +#endif /* CONFIG_DEFERRED_MEM_INIT */ + #ifdef CONFIG_HAVE_MEMORY_PRESENT void memory_present(int nid, unsigned long start, unsigned long end); #else diff --git a/init/main.c b/init/main.c index 6f0f1c5ff8cc..f339d37a43e8 100644 --- a/init/main.c +++ b/init/main.c @@ -506,6 +506,7 @@ asmlinkage __visible void __init start_kernel(void) boot_init_stack_canary(); cgroup_init_early(); + setup_deferred_meminit(); local_irq_disable(); early_boot_irqs_disabled = true; diff --git a/mm/Kconfig b/mm/Kconfig index 463c7005c3d9..0eb9b1349cc2 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -648,3 +648,13 @@ config DEFERRED_MEM_INIT of the system it will still be busy initialising struct pages. This has a potential performance impact on processes until kswapd finishes the initialisation. + +config DEFERRED_MEM_INIT_DEFAULT_ENABLED + bool "Automatically enable deferred memory initialisation" + default y + depends on DEFERRED_MEM_INIT + help + If set, memory initialisation will be deferred by default on large + memory configurations. If DEFERRED_MEM_INIT is set then it is a + reasonable default to enable this too. User will need to disable + this if allocate huge pages from the command line. diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 21bb818aa3c4..cb38583063cb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -236,6 +236,8 @@ EXPORT_SYMBOL(nr_online_nodes); int page_group_by_mobility_disabled __read_mostly; #ifdef CONFIG_DEFERRED_MEM_INIT +bool __meminitdata deferred_mem_init_enabled; + static inline void reset_deferred_meminit(pg_data_t *pgdat) { pgdat->first_deferred_pfn = ULONG_MAX; @@ -268,6 +270,9 @@ static inline bool update_defer_init(pg_data_t *pgdat, unsigned long pfn, unsigned long *nr_initialised) { + if (!deferred_mem_init_enabled) + return true; + if (pgdat->first_deferred_pfn != ULONG_MAX) return false; @@ -281,6 +286,25 @@ static inline bool update_defer_init(pg_data_t *pgdat, return true; } + +static int __init setup_deferred_mem_init(char *str) +{ + if (!str) + return -1; + + if (!strcmp(str, "enable")) { + deferred_mem_init_enabled = true; + } else if (!strcmp(str, "disable")) { + deferred_mem_init_enabled = false; + } else { + pr_warn("Unable to parse deferred_mem_init=\n"); + return -1; + } + + return 0; +} + +early_param("defer_meminit", setup_deferred_mem_init); #else static inline void reset_deferred_meminit(pg_data_t *pgdat) { -- 2.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
