sparc64 mm: Fix base TSB sizing when hugetlb pages are used

[ Upstream commit af1b1a9b36b8f9d583d4b4f90dd8946ed0cd4bd0 ]

do_sparc64_fault() calculates both the base and huge page RSS sizes and
uses this information in calls to tsb_grow().  The calculation for base
page TSB size is not correct if the task uses hugetlb pages.  hugetlb
pages are not accounted for in RSS, therefore the call to get_mm_rss(mm)
does not include hugetlb pages.  However, the number of pages based on
huge_pte_count (which does include hugetlb pages) is subtracted from
this value.  This will result in an artificially small and often negative
RSS calculation.  The base TSB size is then often set to max_tsb_size
as the passed RSS is unsigned, so a negative value looks really big.

THP pages are also accounted for in huge_pte_count, and THP pages are
accounted for in RSS so the calculation in do_sparc64_fault() is correct
if a task only uses THP pages.

A single huge_pte_count is not sufficient for TSB sizing if both hugetlb
and THP pages can be used.  Instead of a single counter, use two:  one
for hugetlb and one for THP.

Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/sparc/include/asm/mmu_64.h b/arch/sparc/include/asm/mmu_64.h
index 70067ce184b16a9d91de2737bf804dbb89e94307..f7de0dbc38af2dd36c9f34df53e6e951f6729825 100644 (file)
--- a/arch/sparc/include/asm/mmu_64.h
+++ b/arch/sparc/include/asm/mmu_64.h
@@ -92,7 +92,8 @@ struct tsb_config {
 typedef struct {
        spinlock_t              lock;
        unsigned long           sparc64_ctx_val;
-       unsigned long           huge_pte_count;
+       unsigned long           hugetlb_pte_count;
+       unsigned long           thp_pte_count;
        struct tsb_config       tsb_block[MM_NUM_TSBS];
        struct hv_tsb_descr     tsb_descr[MM_NUM_TSBS];
 } mm_context_t;

diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index dbabe5713a158eec17eb61de90d1cdfd6e974e80..e15f33715103a14f64b6e63baaf186c1deb81465 100644 (file)
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c
@@ -479,14 +479,14 @@ good_area:
        up_read(&mm->mmap_sem);
 
        mm_rss = get_mm_rss(mm);
-#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-       mm_rss -= (mm->context.huge_pte_count * (HPAGE_SIZE / PAGE_SIZE));
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
+       mm_rss -= (mm->context.thp_pte_count * (HPAGE_SIZE / PAGE_SIZE));
 #endif
        if (unlikely(mm_rss >
                     mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
                tsb_grow(mm, MM_TSB_BASE, mm_rss);
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-       mm_rss = mm->context.huge_pte_count;
+       mm_rss = mm->context.hugetlb_pte_count + mm->context.thp_pte_count;
        if (unlikely(mm_rss >
                     mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
                if (mm->context.tsb_block[MM_TSB_HUGE].tsb)

diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index 364d093f46c6bf50b9dfc0c77935e25871f990bb..da1142401bf4515fe28da9928f14d7a9b55f46aa 100644 (file)
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -180,7 +180,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
        unsigned long nptes;
 
        if (!pte_present(*ptep) && pte_present(entry))
-               mm->context.huge_pte_count++;
+               mm->context.hugetlb_pte_count++;
 
        addr &= HPAGE_MASK;
 
@@ -212,7 +212,7 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 
        entry = *ptep;
        if (pte_present(entry))
-               mm->context.huge_pte_count--;
+               mm->context.hugetlb_pte_count--;
 
        addr &= HPAGE_MASK;
        nptes = 1 << HUGETLB_PAGE_ORDER;

diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 3c4b8975fa76ac555259fec038e50300c424713d..a5331c336b2a9ffd9fa96908a22a1cbc7e34ca67 100644 (file)
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -346,7 +346,8 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *
        spin_lock_irqsave(&mm->context.lock, flags);
 
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-       if (mm->context.huge_pte_count && is_hugetlb_pte(pte))
+       if ((mm->context.hugetlb_pte_count || mm->context.thp_pte_count) &&
+           is_hugetlb_pte(pte))
                __update_mmu_tsb_insert(mm, MM_TSB_HUGE, REAL_HPAGE_SHIFT,
                                        address, pte_val(pte));
        else

diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index f81cd973670079132681d69d0b9800bb12bfbb55..3659d37b4d818e30c614f46cf4b2aca8bf700aa0 100644 (file)
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c
@@ -175,9 +175,9 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 
        if ((pmd_val(pmd) ^ pmd_val(orig)) & _PAGE_PMD_HUGE) {
                if (pmd_val(pmd) & _PAGE_PMD_HUGE)
-                       mm->context.huge_pte_count++;
+                       mm->context.thp_pte_count++;
                else
-                       mm->context.huge_pte_count--;
+                       mm->context.thp_pte_count--;
 
                /* Do not try to allocate the TSB hash table if we
                 * don't have one already.  We have various locks held

diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c
index a0604a493a361e51c055e825e65295a302aeec4c..6725ed45580e525cf5567b1b9ccbeb2c723738bf 100644 (file)
--- a/arch/sparc/mm/tsb.c
+++ b/arch/sparc/mm/tsb.c
@@ -470,7 +470,7 @@ retry_tsb_alloc:
 int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 {
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-       unsigned long huge_pte_count;
+       unsigned long total_huge_pte_count;
 #endif
        unsigned int i;
 
@@ -479,12 +479,14 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
        mm->context.sparc64_ctx_val = 0UL;
 
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-       /* We reset it to zero because the fork() page copying
+       /* We reset them to zero because the fork() page copying
         * will re-increment the counters as the parent PTEs are
         * copied into the child address space.
         */
-       huge_pte_count = mm->context.huge_pte_count;
-       mm->context.huge_pte_count = 0;
+       total_huge_pte_count = mm->context.hugetlb_pte_count +
+                        mm->context.thp_pte_count;
+       mm->context.hugetlb_pte_count = 0;
+       mm->context.thp_pte_count = 0;
 #endif
 
        /* copy_mm() copies over the parent's mm_struct before calling
@@ -500,8 +502,8 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
        tsb_grow(mm, MM_TSB_BASE, get_mm_rss(mm));
 
 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
-       if (unlikely(huge_pte_count))
-               tsb_grow(mm, MM_TSB_HUGE, huge_pte_count);
+       if (unlikely(total_huge_pte_count))
+               tsb_grow(mm, MM_TSB_HUGE, total_huge_pte_count);
 #endif
 
        if (unlikely(!mm->context.tsb_block[MM_TSB_BASE].tsb))