From 985a34bd75cc8c96e43f00dcdda7c3fdb51a3026 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 9 Mar 2008 13:14:37 +0100 Subject: x86: remove quicklists quicklists cause a serious memory leak on 32-bit x86, as documented at: http://bugzilla.kernel.org/show_bug.cgi?id=9991 the reason is that the quicklist pool is a special-purpose cache that grows out of proportion. It is not accounted for anywhere and users have no way to even realize that it's the quicklists that are causing RAM usage spikes. It was supposed to be a relatively small pool, but as demonstrated by KOSAKI Motohiro, they can grow as large as: Quicklists: 1194304 kB given how much trouble this code has caused historically, and given that Andrew objected to its introduction on x86 (years ago), the best option at this point is to remove them. [ any performance benefits of caching constructed pgds should be implemented in a more generic way (possibly within the page allocator), while still allowing constructed pages to be allocated by other workloads. ] Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/mm/pgtable_32.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c index 73aba7125203..2f9e9afcb9f4 100644 --- a/arch/x86/mm/pgtable_32.c +++ b/arch/x86/mm/pgtable_32.c @@ -342,12 +342,16 @@ static void pgd_mop_up_pmds(struct mm_struct *mm, pgd_t *pgdp) pgd_t *pgd_alloc(struct mm_struct *mm) { - pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor); + pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); - mm->pgd = pgd; /* so that alloc_pd can use it */ + /* so that alloc_pd can use it */ + mm->pgd = pgd; + if (pgd) + pgd_ctor(pgd); if (pgd && !pgd_prepopulate_pmd(mm, pgd)) { - quicklist_free(0, pgd_dtor, pgd); + pgd_dtor(pgd); + free_page((unsigned long)pgd); pgd = NULL; } @@ -357,12 +361,8 @@ pgd_t *pgd_alloc(struct mm_struct *mm) void pgd_free(struct mm_struct *mm, pgd_t *pgd) { pgd_mop_up_pmds(mm, pgd); - quicklist_free(0, pgd_dtor, pgd); -} - -void check_pgt_cache(void) -{ - quicklist_trim(0, pgd_dtor, 25, 16); + pgd_dtor(pgd); + free_page((unsigned long)pgd); } void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte) -- cgit v1.2.2