summaryrefslogtreecommitdiff
path: root/arch/s390/mm
diff options
context:
space:
mode:
authorHeiko Carstens <heiko.carstens@de.ibm.com>2012-10-17 12:18:05 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-11-23 11:14:25 +0100
commitf7817968d03df390d77d3af1b13298efa4f31047 (patch)
tree11e355fc56ce3ff4fd433a3fa282881a6481d676 /arch/s390/mm
parent18da236908793abccebc6f365fbe6e95a5b41db0 (diff)
s390/mm,vmemmap: use 1MB frames for vmemmap
Use 1MB frames for vmemmap if EDAT1 is available in order to reduce TLB pressure Always use a 1MB frame even if its only partially needed for struct pages. Otherwise we would end up with a mix of large frame and page mappings, because vmemmap_populate gets called for each section (256MB -> 3.5MB memmap) separately. Worst case is that we would waste 512KB. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm')
-rw-r--r--arch/s390/mm/vmem.c26
1 files changed, 25 insertions, 1 deletions
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index bf37a094a46b..6ed1426d27c5 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -205,7 +205,7 @@ int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
start_addr = (unsigned long) start;
end_addr = (unsigned long) (start + nr);
- for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
+ for (address = start_addr; address < end_addr;) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
pu_dir = vmem_pud_alloc();
@@ -224,10 +224,33 @@ int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir)) {
+#ifdef CONFIG_64BIT
+ /* Use 1MB frames for vmemmap if available. We always
+ * use large frames even if they are only partially
+ * used.
+ * Otherwise we would have also page tables since
+ * vmemmap_populate gets called for each section
+ * separately. */
+ if (MACHINE_HAS_EDAT1) {
+ void *new_page;
+
+ new_page = vmemmap_alloc_block(PMD_SIZE, node);
+ if (!new_page)
+ goto out;
+ pte = mk_pte_phys(__pa(new_page), PAGE_RW);
+ pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
+ pmd_val(*pm_dir) = pte_val(pte);
+ address = (address + PMD_SIZE) & PMD_MASK;
+ continue;
+ }
+#endif
pt_dir = vmem_pte_alloc(address);
if (!pt_dir)
goto out;
pmd_populate(&init_mm, pm_dir, pt_dir);
+ } else if (pmd_large(*pm_dir)) {
+ address = (address + PMD_SIZE) & PMD_MASK;
+ continue;
}
pt_dir = pte_offset_kernel(pm_dir, address);
@@ -240,6 +263,7 @@ int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
*pt_dir = pte;
}
+ address += PAGE_SIZE;
}
memset(start, 0, nr * sizeof(struct page));
ret = 0;