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Commit 12d6f21e authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86: do not PSE on CONFIG_DEBUG_PAGEALLOC=y 



get more testing of the c_p_a() code done by not turning off
PSE on DEBUG_PAGEALLOC.

this simplifies the early pagetable setup code, and tests
the largepage-splitup code quite heavily.

In the end, all the largepages will be split up pretty quickly,
so there's no difference to how DEBUG_PAGEALLOC worked before.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 9a3dc780

arch/x86/kernel/cpu/common.c

+0 −7
Original line number Diff line number Diff line
@@ -641,13 +641,6 @@ void __init early_cpu_init(void) 
	nexgen_init_cpu();

	umc_init_cpu();

	early_cpu_detect();



#ifdef CONFIG_DEBUG_PAGEALLOC

	/* pse is not compatible with on-the-fly unmapping,

	 * disable it even if the cpus claim to support it.

	 */

	setup_clear_cpu_cap(X86_FEATURE_PSE);

#endif

}



/* Make sure %fs is initialized properly in idle threads */

arch/x86/mm/pageattr_32.c

+11 −1
Original line number Diff line number Diff line
@@ -61,13 +61,17 @@ static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) 
static int split_large_page(pte_t *kpte, unsigned long address)

{

	pgprot_t ref_prot = pte_pgprot(pte_clrhuge(*kpte));

	gfp_t gfp_flags = GFP_KERNEL;

	unsigned long flags;

	unsigned long addr;

	pte_t *pbase, *tmp;

	struct page *base;

	int i, level;



	base = alloc_pages(GFP_KERNEL, 0);

#ifdef CONFIG_DEBUG_PAGEALLOC

	gfp_flags = GFP_ATOMIC;

#endif

	base = alloc_pages(gfp_flags, 0);

	if (!base)

		return -ENOMEM;
@@ -218,6 +222,12 @@ void kernel_map_pages(struct page *page, int numpages, int enable) 
					   numpages * PAGE_SIZE);

	}



	/*

	 * If page allocator is not up yet then do not call c_p_a():

	 */

	if (!debug_pagealloc_enabled)

		return;



	/*

	 * the return value is ignored - the calls cannot fail,

	 * large pages are disabled at boot time.

include/asm-x86/cacheflush.h

+0 −5
Original line number Diff line number Diff line
@@ -29,11 +29,6 @@ int change_page_attr(struct page *page, int numpages, pgprot_t prot); 
int change_page_attr_addr(unsigned long addr, int numpages, pgprot_t prot);

void clflush_cache_range(void *addr, int size);



#ifdef CONFIG_DEBUG_PAGEALLOC

/* internal debugging function */

void kernel_map_pages(struct page *page, int numpages, int enable);

#endif



#ifdef CONFIG_DEBUG_RODATA

void mark_rodata_ro(void);

#endif

include/linux/mm.h

+13 −1
Original line number Diff line number Diff line
@@ -1118,9 +1118,21 @@ static inline void vm_stat_account(struct mm_struct *mm, 
}

#endif /* CONFIG_PROC_FS */



#ifndef CONFIG_DEBUG_PAGEALLOC

#ifdef CONFIG_DEBUG_PAGEALLOC

extern int debug_pagealloc_enabled;



extern void kernel_map_pages(struct page *page, int numpages, int enable);



static inline void enable_debug_pagealloc(void)

{

	debug_pagealloc_enabled = 1;

}

#else

static inline void

kernel_map_pages(struct page *page, int numpages, int enable) {}

static inline void enable_debug_pagealloc(void)

{

}

#endif



extern struct vm_area_struct *get_gate_vma(struct task_struct *tsk);

init/main.c

+5 −0
Original line number Diff line number Diff line
@@ -318,6 +318,10 @@ static int __init unknown_bootoption(char *param, char *val) 
	return 0;

}



#ifdef CONFIG_DEBUG_PAGEALLOC

int __read_mostly debug_pagealloc_enabled = 0;

#endif



static int __init init_setup(char *str)

{

	unsigned int i;
@@ -552,6 +556,7 @@ asmlinkage void __init start_kernel(void) 
	preempt_disable();

	build_all_zonelists();

	page_alloc_init();

	enable_debug_pagealloc();

	printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);

	parse_early_param();

	parse_args("Booting kernel", static_command_line, __start___param,