diff options
Diffstat (limited to 'mm/mmu_gather.c')
| -rw-r--r-- | mm/mmu_gather.c | 124 |
1 files changed, 94 insertions, 30 deletions
diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c index 03c33c93a582..604ddf08affe 100644 --- a/mm/mmu_gather.c +++ b/mm/mmu_gather.c @@ -3,10 +3,12 @@ #include <linux/kernel.h> #include <linux/mmdebug.h> #include <linux/mm_types.h> +#include <linux/mm_inline.h> #include <linux/pagemap.h> #include <linux/rcupdate.h> #include <linux/smp.h> #include <linux/swap.h> +#include <linux/rmap.h> #include <asm/pgalloc.h> #include <asm/tlb.h> @@ -17,6 +19,10 @@ static bool tlb_next_batch(struct mmu_gather *tlb) { struct mmu_gather_batch *batch; + /* Limit batching if we have delayed rmaps pending */ + if (tlb->delayed_rmap && tlb->active != &tlb->local) + return false; + batch = tlb->active; if (batch->next) { tlb->active = batch->next; @@ -26,7 +32,7 @@ static bool tlb_next_batch(struct mmu_gather *tlb) if (tlb->batch_count == MAX_GATHER_BATCH_COUNT) return false; - batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); + batch = (void *)__get_free_page(GFP_NOWAIT | __GFP_NOWARN); if (!batch) return false; @@ -41,13 +47,60 @@ static bool tlb_next_batch(struct mmu_gather *tlb) return true; } +#ifdef CONFIG_SMP +static void tlb_flush_rmap_batch(struct mmu_gather_batch *batch, struct vm_area_struct *vma) +{ + for (int i = 0; i < batch->nr; i++) { + struct encoded_page *enc = batch->encoded_pages[i]; + + if (encoded_page_flags(enc)) { + struct page *page = encoded_page_ptr(enc); + folio_remove_rmap_pte(page_folio(page), page, vma); + } + } +} + +/** + * tlb_flush_rmaps - do pending rmap removals after we have flushed the TLB + * @tlb: the current mmu_gather + * @vma: The memory area from which the pages are being removed. + * + * Note that because of how tlb_next_batch() above works, we will + * never start multiple new batches with pending delayed rmaps, so + * we only need to walk through the current active batch and the + * original local one. + */ +void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + if (!tlb->delayed_rmap) + return; + + tlb_flush_rmap_batch(&tlb->local, vma); + if (tlb->active != &tlb->local) + tlb_flush_rmap_batch(tlb->active, vma); + tlb->delayed_rmap = 0; +} +#endif + static void tlb_batch_pages_flush(struct mmu_gather *tlb) { struct mmu_gather_batch *batch; for (batch = &tlb->local; batch && batch->nr; batch = batch->next) { - free_pages_and_swap_cache(batch->pages, batch->nr); - batch->nr = 0; + struct encoded_page **pages = batch->encoded_pages; + + do { + /* + * limit free batch count when PAGE_SIZE > 4K + */ + unsigned int nr = min(512U, batch->nr); + + free_pages_and_swap_cache(pages, nr); + pages += nr; + batch->nr -= nr; + + cond_resched(); + } while (batch->nr); } tlb->active = &tlb->local; } @@ -63,7 +116,7 @@ static void tlb_batch_list_free(struct mmu_gather *tlb) tlb->local.next = NULL; } -bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int page_size) +bool __tlb_remove_page_size(struct mmu_gather *tlb, struct encoded_page *page, int page_size) { struct mmu_gather_batch *batch; @@ -78,13 +131,13 @@ bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int page_ * Add the page and check if we are full. If so * force a flush. */ - batch->pages[batch->nr++] = page; + batch->encoded_pages[batch->nr++] = page; if (batch->nr == batch->max) { if (!tlb_next_batch(tlb)) return true; batch = tlb->active; } - VM_BUG_ON_PAGE(batch->nr > batch->max, page); + VM_BUG_ON_PAGE(batch->nr > batch->max, encoded_page_ptr(page)); return false; } @@ -139,7 +192,7 @@ static void tlb_remove_table_smp_sync(void *arg) /* Simply deliver the interrupt */ } -static void tlb_remove_table_sync_one(void) +void tlb_remove_table_sync_one(void) { /* * This isn't an RCU grace period and hence the page-tables cannot be @@ -163,8 +216,6 @@ static void tlb_remove_table_free(struct mmu_table_batch *batch) #else /* !CONFIG_MMU_GATHER_RCU_TABLE_FREE */ -static void tlb_remove_table_sync_one(void) { } - static void tlb_remove_table_free(struct mmu_table_batch *batch) { __tlb_remove_table_free(batch); @@ -249,25 +300,11 @@ void tlb_flush_mmu(struct mmu_gather *tlb) tlb_flush_mmu_free(tlb); } -/** - * tlb_gather_mmu - initialize an mmu_gather structure for page-table tear-down - * @tlb: the mmu_gather structure to initialize - * @mm: the mm_struct of the target address space - * @start: start of the region that will be removed from the page-table - * @end: end of the region that will be removed from the page-table - * - * Called to initialize an (on-stack) mmu_gather structure for page-table - * tear-down from @mm. The @start and @end are set to 0 and -1 - * respectively when @mm is without users and we're going to destroy - * the full address space (exit/execve). - */ -void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, - unsigned long start, unsigned long end) +static void __tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, + bool fullmm) { tlb->mm = mm; - - /* Is it from 0 to ~0? */ - tlb->fullmm = !(start | (end+1)); + tlb->fullmm = fullmm; #ifndef CONFIG_MMU_GATHER_NO_GATHER tlb->need_flush_all = 0; @@ -277,6 +314,7 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, tlb->active = &tlb->local; tlb->batch_count = 0; #endif + tlb->delayed_rmap = 0; tlb_table_init(tlb); #ifdef CONFIG_MMU_GATHER_PAGE_SIZE @@ -288,16 +326,42 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, } /** + * tlb_gather_mmu - initialize an mmu_gather structure for page-table tear-down + * @tlb: the mmu_gather structure to initialize + * @mm: the mm_struct of the target address space + * + * Called to initialize an (on-stack) mmu_gather structure for page-table + * tear-down from @mm. + */ +void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm) +{ + __tlb_gather_mmu(tlb, mm, false); +} + +/** + * tlb_gather_mmu_fullmm - initialize an mmu_gather structure for page-table tear-down + * @tlb: the mmu_gather structure to initialize + * @mm: the mm_struct of the target address space + * + * In this case, @mm is without users and we're going to destroy the + * full address space (exit/execve). + * + * Called to initialize an (on-stack) mmu_gather structure for page-table + * tear-down from @mm. + */ +void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm) +{ + __tlb_gather_mmu(tlb, mm, true); +} + +/** * tlb_finish_mmu - finish an mmu_gather structure * @tlb: the mmu_gather structure to finish - * @start: start of the region that will be removed from the page-table - * @end: end of the region that will be removed from the page-table * * Called at the end of the shootdown operation to free up any resources that * were required. */ -void tlb_finish_mmu(struct mmu_gather *tlb, - unsigned long start, unsigned long end) +void tlb_finish_mmu(struct mmu_gather *tlb) { /* * If there are parallel threads are doing PTE changes on same range |