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Commit f1d1a842 authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

SLUB: i386 support 



SLUB cannot run on i386 at this point because i386 uses the page->private and
page->index field of slab pages for the pgd cache.

Make SLUB run on i386 by replacing the pgd slab cache with a quicklist.
Limit the changes as much as possible. Leave the improvised linked list in place
etc etc. This has been working here for a couple of weeks now.

Acked-by: default avatarWilliam Lee Irwin III <wli@holomorphy.com>
Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8df767dd

arch/i386/Kconfig

+4 −4
Original line number Diff line number Diff line
@@ -55,6 +55,10 @@ config ZONE_DMA 
	bool

	default y



config QUICKLIST

	bool

	default y



config SBUS

	bool
@@ -79,10 +83,6 @@ config ARCH_MAY_HAVE_PC_FDC 
	bool

	default y



config ARCH_USES_SLAB_PAGE_STRUCT

	bool

	default y



config DMI

	bool

	default y

arch/i386/kernel/process.c

+1 −0
Original line number Diff line number Diff line
@@ -186,6 +186,7 @@ void cpu_idle(void) 
			if (__get_cpu_var(cpu_idle_state))

				__get_cpu_var(cpu_idle_state) = 0;



			check_pgt_cache();

			rmb();

			idle = pm_idle;

arch/i386/kernel/smp.c

+1 −1
Original line number Diff line number Diff line
@@ -421,7 +421,7 @@ void flush_tlb_mm (struct mm_struct * mm) 
	}

	if (!cpus_empty(cpu_mask))

		flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL);



	check_pgt_cache();

	preempt_enable();

}

arch/i386/mm/init.c

+0 −7
Original line number Diff line number Diff line
@@ -740,7 +740,6 @@ int remove_memory(u64 start, u64 size) 
EXPORT_SYMBOL_GPL(remove_memory);

#endif



struct kmem_cache *pgd_cache;

struct kmem_cache *pmd_cache;



void __init pgtable_cache_init(void)
@@ -764,12 +763,6 @@ void __init pgtable_cache_init(void) 
			pgd_size = PAGE_SIZE;

		}

	}

	pgd_cache = kmem_cache_create("pgd",

				pgd_size,

				pgd_size,

				SLAB_PANIC,

				pgd_ctor,

				(!SHARED_KERNEL_PMD) ? pgd_dtor : NULL);

}



/*

arch/i386/mm/pgtable.c

+17 −9
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/pagemap.h>

#include <linux/spinlock.h>

#include <linux/module.h>

#include <linux/quicklist.h>



#include <asm/system.h>

#include <asm/pgtable.h>
@@ -205,8 +206,6 @@ void pmd_ctor(void *pmd, struct kmem_cache *cache, unsigned long flags) 
 * against pageattr.c; it is the unique case in which a valid change

 * of kernel pagetables can't be lazily synchronized by vmalloc faults.

 * vmalloc faults work because attached pagetables are never freed.

 * The locking scheme was chosen on the basis of manfred's

 * recommendations and having no core impact whatsoever.

 * -- wli

 */

DEFINE_SPINLOCK(pgd_lock);
@@ -232,9 +231,11 @@ static inline void pgd_list_del(pgd_t *pgd) 
		set_page_private(next, (unsigned long)pprev);

}







#if (PTRS_PER_PMD == 1)

/* Non-PAE pgd constructor */

void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)

void pgd_ctor(void *pgd)

{

	unsigned long flags;
@@ -256,7 +257,7 @@ void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused) 
}

#else  /* PTRS_PER_PMD > 1 */

/* PAE pgd constructor */

void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)

void pgd_ctor(void *pgd)

{

	/* PAE, kernel PMD may be shared */
@@ -275,11 +276,12 @@ void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused) 
}

#endif	/* PTRS_PER_PMD */



void pgd_dtor(void *pgd, struct kmem_cache *cache, unsigned long unused)

void pgd_dtor(void *pgd)

{

	unsigned long flags; /* can be called from interrupt context */



	BUG_ON(SHARED_KERNEL_PMD);

	if (SHARED_KERNEL_PMD)

		return;



	paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);

	spin_lock_irqsave(&pgd_lock, flags);
@@ -321,7 +323,7 @@ static void pmd_cache_free(pmd_t *pmd, int idx) 
pgd_t *pgd_alloc(struct mm_struct *mm)

{

	int i;

	pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);

	pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor);



	if (PTRS_PER_PMD == 1 || !pgd)

		return pgd;
@@ -344,7 +346,7 @@ pgd_t *pgd_alloc(struct mm_struct *mm) 
		paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);

		pmd_cache_free(pmd, i);

	}

	kmem_cache_free(pgd_cache, pgd);

	quicklist_free(0, pgd_dtor, pgd);

	return NULL;

}
@@ -361,5 +363,11 @@ void pgd_free(pgd_t *pgd) 
			pmd_cache_free(pmd, i);

		}

	/* in the non-PAE case, free_pgtables() clears user pgd entries */

	kmem_cache_free(pgd_cache, pgd);

	quicklist_free(0, pgd_dtor, pgd);

}



void check_pgt_cache(void)

{

	quicklist_trim(0, pgd_dtor, 25, 16);

}