Merge branch 'x86/urgent' into x86/cleanups

5 files changed, 106 insertions, 37 deletions

diff --git a/mm/bootmem.c b/mm/bootmem.c
index e023c68b0255..ad8eec6e44a8 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -405,6 +405,29 @@ int __init reserve_bootmem(unsigned long addr, unsigned long size,
 }
 #endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
 
+static unsigned long align_idx(struct bootmem_data *bdata, unsigned long idx,
+			unsigned long step)
+{
+	unsigned long base = bdata->node_min_pfn;
+
+	/*
+	 * Align the index with respect to the node start so that the
+	 * combination of both satisfies the requested alignment.
+	 */
+
+	return ALIGN(base + idx, step) - base;
+}
+
+static unsigned long align_off(struct bootmem_data *bdata, unsigned long off,
+			unsigned long align)
+{
+	unsigned long base = PFN_PHYS(bdata->node_min_pfn);
+
+	/* Same as align_idx for byte offsets */
+
+	return ALIGN(base + off, align) - base;
+}
+
 static void * __init alloc_bootmem_core(struct bootmem_data *bdata,
 				unsigned long size, unsigned long align,
 				unsigned long goal, unsigned long limit)
@@ -441,7 +464,7 @@ static void * __init alloc_bootmem_core(struct bootmem_data *bdata,
 	else
 		start = ALIGN(min, step);
 
-	sidx = start - bdata->node_min_pfn;;
+	sidx = start - bdata->node_min_pfn;
 	midx = max - bdata->node_min_pfn;
 
 	if (bdata->hint_idx > sidx) {
@@ -450,7 +473,7 @@ static void * __init alloc_bootmem_core(struct bootmem_data *bdata,
 		 * catch the fallback below.
 		 */
 		fallback = sidx + 1;
-		sidx = ALIGN(bdata->hint_idx, step);
+		sidx = align_idx(bdata, bdata->hint_idx, step);
 	}
 
 	while (1) {
@@ -459,7 +482,7 @@ static void * __init alloc_bootmem_core(struct bootmem_data *bdata,
 		unsigned long eidx, i, start_off, end_off;
 find_block:
 		sidx = find_next_zero_bit(bdata->node_bootmem_map, midx, sidx);
-		sidx = ALIGN(sidx, step);
+		sidx = align_idx(bdata, sidx, step);
 		eidx = sidx + PFN_UP(size);
 
 		if (sidx >= midx || eidx > midx)
@@ -467,7 +490,7 @@ find_block:
 
 		for (i = sidx; i < eidx; i++)
 			if (test_bit(i, bdata->node_bootmem_map)) {
-				sidx = ALIGN(i, step);
+				sidx = align_idx(bdata, i, step);
 				if (sidx == i)
 					sidx += step;
 				goto find_block;
@@ -475,7 +498,7 @@ find_block:
 
 		if (bdata->last_end_off & (PAGE_SIZE - 1) &&
 				PFN_DOWN(bdata->last_end_off) + 1 == sidx)
-			start_off = ALIGN(bdata->last_end_off, align);
+			start_off = align_off(bdata, bdata->last_end_off, align);
 		else
 			start_off = PFN_PHYS(sidx);
 
@@ -499,7 +522,7 @@ find_block:
 	}
 
 	if (fallback) {
-		sidx = ALIGN(fallback - 1, step);
+		sidx = align_idx(bdata, fallback - 1, step);
 		fallback = 0;
 		goto find_block;
 	}
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 380ab402d711..b5167dfb2f2d 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -15,6 +15,8 @@
 #include <linux/rmap.h>
 #include <linux/mmu_notifier.h>
 #include <linux/sched.h>
+#include <linux/seqlock.h>
+#include <linux/mutex.h>
 #include <asm/tlbflush.h>
 #include <asm/io.h>
 
@@ -22,22 +24,18 @@
  * We do use our own empty page to avoid interference with other users
  * of ZERO_PAGE(), such as /dev/zero
  */
+static DEFINE_MUTEX(xip_sparse_mutex);
+static seqcount_t xip_sparse_seq = SEQCNT_ZERO;
 static struct page *__xip_sparse_page;
 
+/* called under xip_sparse_mutex */
 static struct page *xip_sparse_page(void)
 {
 	if (!__xip_sparse_page) {
 		struct page *page = alloc_page(GFP_HIGHUSER | __GFP_ZERO);
 
-		if (page) {
-			static DEFINE_SPINLOCK(xip_alloc_lock);
-			spin_lock(&xip_alloc_lock);
-			if (!__xip_sparse_page)
-				__xip_sparse_page = page;
-			else
-				__free_page(page);
-			spin_unlock(&xip_alloc_lock);
-		}
+		if (page)
+			__xip_sparse_page = page;
 	}
 	return __xip_sparse_page;
 }
@@ -174,18 +172,23 @@ __xip_unmap (struct address_space * mapping,
 	pte_t pteval;
 	spinlock_t *ptl;
 	struct page *page;
+	unsigned count;
+	int locked = 0;
+
+	count = read_seqcount_begin(&xip_sparse_seq);
 
 	page = __xip_sparse_page;
 	if (!page)
 		return;
 
+retry:
 	spin_lock(&mapping->i_mmap_lock);
 	vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
 		mm = vma->vm_mm;
 		address = vma->vm_start +
 			((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
 		BUG_ON(address < vma->vm_start || address >= vma->vm_end);
-		pte = page_check_address(page, mm, address, &ptl);
+		pte = page_check_address(page, mm, address, &ptl, 1);
 		if (pte) {
 			/* Nuke the page table entry. */
 			flush_cache_page(vma, address, pte_pfn(*pte));
@@ -198,6 +201,14 @@ __xip_unmap (struct address_space * mapping,
 		}
 	}
 	spin_unlock(&mapping->i_mmap_lock);
+
+	if (locked) {
+		mutex_unlock(&xip_sparse_mutex);
+	} else if (read_seqcount_retry(&xip_sparse_seq, count)) {
+		mutex_lock(&xip_sparse_mutex);
+		locked = 1;
+		goto retry;
+	}
 }
 
 /*
@@ -218,7 +229,7 @@ static int xip_file_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	int error;
 
 	/* XXX: are VM_FAULT_ codes OK? */
-
+again:
 	size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 	if (vmf->pgoff >= size)
 		return VM_FAULT_SIGBUS;
@@ -237,8 +248,10 @@ static int xip_file_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		int err;
 
 		/* maybe shared writable, allocate new block */
+		mutex_lock(&xip_sparse_mutex);
 		error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 1,
 							&xip_mem, &xip_pfn);
+		mutex_unlock(&xip_sparse_mutex);
 		if (error)
 			return VM_FAULT_SIGBUS;
 		/* unmap sparse mappings at pgoff from all other vmas */
@@ -252,14 +265,34 @@ found:
 		BUG_ON(err);
 		return VM_FAULT_NOPAGE;
 	} else {
+		int err, ret = VM_FAULT_OOM;
+
+		mutex_lock(&xip_sparse_mutex);
+		write_seqcount_begin(&xip_sparse_seq);
+		error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 0,
+							&xip_mem, &xip_pfn);
+		if (unlikely(!error)) {
+			write_seqcount_end(&xip_sparse_seq);
+			mutex_unlock(&xip_sparse_mutex);
+			goto again;
+		}
+		if (error != -ENODATA)
+			goto out;
 		/* not shared and writable, use xip_sparse_page() */
 		page = xip_sparse_page();
 		if (!page)
-			return VM_FAULT_OOM;
+			goto out;
+		err = vm_insert_page(vma, (unsigned long)vmf->virtual_address,
+							page);
+		if (err == -ENOMEM)
+			goto out;
 
-		page_cache_get(page);
-		vmf->page = page;
-		return 0;
+		ret = VM_FAULT_NOPAGE;
+out:
+		write_seqcount_end(&xip_sparse_seq);
+		mutex_unlock(&xip_sparse_mutex);
+
+		return ret;
 	}
 }
 
@@ -308,8 +341,10 @@ __xip_file_write(struct file *filp, const char __user *buf,
 						&xip_mem, &xip_pfn);
 		if (status == -ENODATA) {
 			/* we allocate a new page unmap it */
+			mutex_lock(&xip_sparse_mutex);
 			status = a_ops->get_xip_mem(mapping, index, 1,
 							&xip_mem, &xip_pfn);
+			mutex_unlock(&xip_sparse_mutex);
 			if (!status)
 				/* unmap page at pgoff from all other vmas */
 				__xip_unmap(mapping, index);
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 936ef2efd892..4e0e26591dfa 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -12,7 +12,7 @@
 #include "internal.h"
 
 #ifdef CONFIG_DEBUG_MEMORY_INIT
-int __meminitdata mminit_loglevel;
+int mminit_loglevel;
 
 #ifndef SECTIONS_SHIFT
 #define SECTIONS_SHIFT	0
diff --git a/mm/rmap.c b/mm/rmap.c
index 1ea4e6fcee77..0383acfcb068 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -224,10 +224,14 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
 /*
  * Check that @page is mapped at @address into @mm.
  *
+ * If @sync is false, page_check_address may perform a racy check to avoid
+ * the page table lock when the pte is not present (helpful when reclaiming
+ * highly shared pages).
+ *
  * On success returns with pte mapped and locked.
  */
 pte_t *page_check_address(struct page *page, struct mm_struct *mm,
-			  unsigned long address, spinlock_t **ptlp)
+			  unsigned long address, spinlock_t **ptlp, int sync)
 {
 	pgd_t *pgd;
 	pud_t *pud;
@@ -249,7 +253,7 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm,
 
 	pte = pte_offset_map(pmd, address);
 	/* Make a quick check before getting the lock */
-	if (!pte_present(*pte)) {
+	if (!sync && !pte_present(*pte)) {
 		pte_unmap(pte);
 		return NULL;
 	}
@@ -281,7 +285,7 @@ static int page_referenced_one(struct page *page,
 	if (address == -EFAULT)
 		goto out;
 
-	pte = page_check_address(page, mm, address, &ptl);
+	pte = page_check_address(page, mm, address, &ptl, 0);
 	if (!pte)
 		goto out;
 
@@ -450,7 +454,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma)
 	if (address == -EFAULT)
 		goto out;
 
-	pte = page_check_address(page, mm, address, &ptl);
+	pte = page_check_address(page, mm, address, &ptl, 1);
 	if (!pte)
 		goto out;
 
@@ -659,23 +663,30 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma)
 		}
 
 		/*
-		 * It would be tidy to reset the PageAnon mapping here,
-		 * but that might overwrite a racing page_add_anon_rmap
-		 * which increments mapcount after us but sets mapping
-		 * before us: so leave the reset to free_hot_cold_page,
-		 * and remember that it's only reliable while mapped.
-		 * Leaving it set also helps swapoff to reinstate ptes
-		 * faster for those pages still in swapcache.
+		 * Now that the last pte has gone, s390 must transfer dirty
+		 * flag from storage key to struct page.  We can usually skip
+		 * this if the page is anon, so about to be freed; but perhaps
+		 * not if it's in swapcache - there might be another pte slot
+		 * containing the swap entry, but page not yet written to swap.
 		 */
 		if ((!PageAnon(page) || PageSwapCache(page)) &&
 		    page_test_dirty(page)) {
 			page_clear_dirty(page);
 			set_page_dirty(page);
 		}
-		mem_cgroup_uncharge_page(page);
 
+		mem_cgroup_uncharge_page(page);
 		__dec_zone_page_state(page,
-				PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
+			PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
+		/*
+		 * It would be tidy to reset the PageAnon mapping here,
+		 * but that might overwrite a racing page_add_anon_rmap
+		 * which increments mapcount after us but sets mapping
+		 * before us: so leave the reset to free_hot_cold_page,
+		 * and remember that it's only reliable while mapped.
+		 * Leaving it set also helps swapoff to reinstate ptes
+		 * faster for those pages still in swapcache.
+		 */
 	}
 }
 
@@ -697,7 +708,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 	if (address == -EFAULT)
 		goto out;
 
-	pte = page_check_address(page, mm, address, &ptl);
+	pte = page_check_address(page, mm, address, &ptl, 0);
 	if (!pte)
 		goto out;
 
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 167cf2dc8a03..797c3831cbec 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -60,7 +60,7 @@ void show_swap_cache_info(void)
 	printk("Swap cache stats: add %lu, delete %lu, find %lu/%lu\n",
 		swap_cache_info.add_total, swap_cache_info.del_total,
 		swap_cache_info.find_success, swap_cache_info.find_total);
-	printk("Free swap  = %lukB\n", nr_swap_pages << (PAGE_SHIFT - 10));
+	printk("Free swap  = %ldkB\n", nr_swap_pages << (PAGE_SHIFT - 10));
 	printk("Total swap = %lukB\n", total_swap_pages << (PAGE_SHIFT - 10));
 }