From d08d4e7cd6bffe333f09853005aa549a8d57614b Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Thu, 12 Oct 2023 20:28:51 +0200 Subject: s390/mm: use full 4KB page for 2KB PTE Cease using 4KB pages to host two 2KB PTEs. That greatly simplifies the memory management code at the expense of page tables memory footprint. Instead of two PTEs per 4KB page use only upper half of the parent page for a single PTE. With that the list of half-used pages pgtable_list becomes unneeded. Further, the upper byte of the parent page _refcount counter does not need to be used for fragments tracking and could be left alone. Commit 8211dad62798 ("s390: add pte_free_defer() for pgtables sharing page") introduced the use of PageActive flag to coordinate a deferred free with 2KB page table fragments tracking. Since there is no tracking anymore, there is no need for using PageActive flag. Reviewed-by: Heiko Carstens Reviewed-by: Gerald Schaefer Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik --- arch/s390/include/asm/mmu.h | 2 -- arch/s390/include/asm/mmu_context.h | 1 - arch/s390/include/asm/tlb.h | 5 ----- 3 files changed, 8 deletions(-) (limited to 'arch/s390/include/asm') diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h index 829d68e2c685..bb1b4bef1878 100644 --- a/arch/s390/include/asm/mmu.h +++ b/arch/s390/include/asm/mmu.h @@ -11,7 +11,6 @@ typedef struct { cpumask_t cpu_attach_mask; atomic_t flush_count; unsigned int flush_mm; - struct list_head pgtable_list; struct list_head gmap_list; unsigned long gmap_asce; unsigned long asce; @@ -39,7 +38,6 @@ typedef struct { #define INIT_MM_CONTEXT(name) \ .context.lock = __SPIN_LOCK_UNLOCKED(name.context.lock), \ - .context.pgtable_list = LIST_HEAD_INIT(name.context.pgtable_list), \ .context.gmap_list = LIST_HEAD_INIT(name.context.gmap_list), #endif diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h index 757fe6f0d802..929af18b0908 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h @@ -22,7 +22,6 @@ static inline int init_new_context(struct task_struct *tsk, unsigned long asce_type, init_entry; spin_lock_init(&mm->context.lock); - INIT_LIST_HEAD(&mm->context.pgtable_list); INIT_LIST_HEAD(&mm->context.gmap_list); cpumask_clear(&mm->context.cpu_attach_mask); atomic_set(&mm->context.flush_count, 0); diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h index a0089b2e5e67..3f0fec0a1e3c 100644 --- a/arch/s390/include/asm/tlb.h +++ b/arch/s390/include/asm/tlb.h @@ -69,11 +69,6 @@ static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, tlb->mm->context.flush_mm = 1; tlb->freed_tables = 1; tlb->cleared_pmds = 1; - /* - * page_table_free_rcu takes care of the allocation bit masks - * of the 2K table fragments in the 4K page table page, - * then calls tlb_remove_table. - */ page_table_free_rcu(tlb, (unsigned long *) pte, address); } -- cgit v1.2.3