ALSA: seq: Fix race during FIFO resize

[pandora-kernel.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index f6a621b..390f0ac 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1417,6 +1417,10 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
                 * and reducing the surplus.
                 */
                spin_unlock(&hugetlb_lock);
+
+               /* yield cpu to avoid soft lockup */
+               cond_resched();
+
                ret = alloc_fresh_huge_page(h, nodes_allowed);
                spin_lock(&hugetlb_lock);
                if (!ret)
@@ -1889,11 +1893,7 @@ module_exit(hugetlb_exit);
 
 static int __init hugetlb_init(void)
 {
-       /* Some platform decide whether they support huge pages at boot
-        * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when
-        * there is no such support
-        */
-       if (HPAGE_SHIFT == 0)
+       if (!hugepages_supported())
                return 0;
 
        if (!size_to_hstate(default_hstate_size)) {
@@ -2010,6 +2010,9 @@ static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
        unsigned long tmp;
        int ret;
 
+       if (!hugepages_supported())
+               return -ENOTSUPP;
+
        tmp = h->max_huge_pages;
 
        if (write && h->order >= MAX_ORDER)
@@ -2075,6 +2078,9 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write,
        unsigned long tmp;
        int ret;
 
+       if (!hugepages_supported())
+               return -ENOTSUPP;
+
        tmp = h->nr_overcommit_huge_pages;
 
        if (write && h->order >= MAX_ORDER)
@@ -2100,6 +2106,8 @@ out:
 void hugetlb_report_meminfo(struct seq_file *m)
 {
        struct hstate *h = &default_hstate;
+       if (!hugepages_supported())
+               return;
        seq_printf(m,
                        "HugePages_Total:   %5lu\n"
                        "HugePages_Free:    %5lu\n"
@@ -2116,6 +2124,8 @@ void hugetlb_report_meminfo(struct seq_file *m)
 int hugetlb_report_node_meminfo(int nid, char *buf)
 {
        struct hstate *h = &default_hstate;
+       if (!hugepages_supported())
+               return 0;
        return sprintf(buf,
                "Node %d HugePages_Total: %5u\n"
                "Node %d HugePages_Free:  %5u\n"
@@ -2418,9 +2428,10 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
                        continue;
 
                /*
-                * HWPoisoned hugepage is already unmapped and dropped reference
+                * Migrating hugepage or HWPoisoned hugepage is already
+                * unmapped and its refcount is dropped
                 */
-               if (unlikely(is_hugetlb_entry_hwpoisoned(pte)))
+               if (unlikely(!pte_present(pte)))
                        continue;
 
                page = pte_page(pte);
@@ -2500,6 +2511,14 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
                if (iter_vma == vma)
                        continue;
 
+               /*
+                * Shared VMAs have their own reserves and do not affect
+                * MAP_PRIVATE accounting but it is possible that a shared
+                * VMA is using the same page so check and skip such VMAs.
+                */
+               if (iter_vma->vm_flags & VM_MAYSHARE)
+                       continue;
+
                /*
                 * Unmap the page from other VMAs without their own reserves.
                 * They get marked to be SIGKILLed if they fault in these
@@ -2809,12 +2828,12 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
                        return VM_FAULT_HWPOISON_LARGE |
                               VM_FAULT_SET_HINDEX(h - hstates);
+       } else {
+               ptep = huge_pte_alloc(mm, address, huge_page_size(h));
+               if (!ptep)
+                       return VM_FAULT_OOM;
        }
 
-       ptep = huge_pte_alloc(mm, address, huge_page_size(h));
-       if (!ptep)
-               return VM_FAULT_OOM;
-
        /*
         * Serialize hugepage allocation and instantiation, so that we don't
         * get spurious allocation failures if two CPUs race to instantiate
@@ -3037,7 +3056,22 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
                        continue;
                if (huge_pmd_unshare(mm, &address, ptep))
                        continue;
-               if (!huge_pte_none(huge_ptep_get(ptep))) {
+               pte = huge_ptep_get(ptep);
+               if (unlikely(is_hugetlb_entry_hwpoisoned(pte)))
+                       continue;
+               if (unlikely(is_hugetlb_entry_migration(pte))) {
+                       swp_entry_t entry = pte_to_swp_entry(pte);
+
+                       if (is_write_migration_entry(entry)) {
+                               pte_t newpte;
+
+                               make_migration_entry_read(&entry);
+                               newpte = swp_entry_to_pte(entry);
+                               set_huge_pte_at(mm, address, ptep, newpte);
+                       }
+                       continue;
+               }
+               if (!huge_pte_none(pte)) {
                        pte = huge_ptep_get_and_clear(mm, address, ptep);
                        pte = pte_mkhuge(pte_modify(pte, newprot));
                        set_huge_pte_at(mm, address, ptep, pte);