Dave Hansen wrote:
> On 04/17/2013 07:38 AM, Kirill A. Shutemov wrote:
> Are you still sure you can't do _any_ better than a verbatim copy of 129
> lines?
It seems I was too lazy. Shame on me. :(
Here's consolidated version. Only build tested. Does it look better?
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 1c25b90..47651d4 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -186,6 +186,28 @@ static inline struct page *compound_trans_head(struct page
*page)
return page;
}
+static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp)
+{
+ return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT)) | extra_gfp;
+}
+
+static inline struct page *alloc_hugepage_vma(int defrag,
+ struct vm_area_struct *vma,
+ unsigned long haddr, int nd,
+ gfp_t extra_gfp)
+{
+ return alloc_pages_vma(alloc_hugepage_gfpmask(defrag, extra_gfp),
+ HPAGE_PMD_ORDER, vma, haddr, nd);
+}
+
+static inline pmd_t mk_huge_pmd(struct page *page, pgprot_t prot)
+{
+ pmd_t entry;
+ entry = mk_pmd(page, prot);
+ entry = pmd_mkhuge(entry);
+ return entry;
+}
+
extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct
*vma,
unsigned long addr, pmd_t pmd, pmd_t *pmdp);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c8a8626..4669c19 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -165,6 +165,11 @@ extern pgprot_t protection_map[16];
#define FAULT_FLAG_RETRY_NOWAIT 0x10 /* Don't drop mmap_sem and wait
when retrying */
#define FAULT_FLAG_KILLABLE 0x20 /* The fault task is in SIGKILL
killable region */
#define FAULT_FLAG_TRIED 0x40 /* second try */
+#ifdef CONFIG_CONFIG_TRANSPARENT_HUGEPAGE
+#define FAULT_FLAG_TRANSHUGE 0x80 /* Try to allocate transhuge
page */
+#else
+#define FAULT_FLAG_TRANSHUGE 0 /* Optimize out THP code if disabled*/
+#endif
/*
* vm_fault is filled by the the pagefault handler and passed to the vma's
@@ -880,6 +885,7 @@ static inline int page_mapped(struct page *page)
#define VM_FAULT_NOPAGE 0x0100 /* ->fault installed the pte, not
return page */
#define VM_FAULT_LOCKED 0x0200 /* ->fault locked the returned page */
#define VM_FAULT_RETRY 0x0400 /* ->fault blocked, must retry */
+#define VM_FAULT_FALLBACK 0x0800 /* large page fault failed, fall back
to small */
#define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large
hwpoison */
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 73691a3..e14fa81 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -692,14 +692,6 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct
*vma)
return pmd;
}
-static inline pmd_t mk_huge_pmd(struct page *page, pgprot_t prot)
-{
- pmd_t entry;
- entry = mk_pmd(page, prot);
- entry = pmd_mkhuge(entry);
- return entry;
-}
-
static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
struct vm_area_struct *vma,
unsigned long haddr, pmd_t *pmd,
@@ -742,20 +734,6 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct
*mm,
return 0;
}
-static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp)
-{
- return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT)) | extra_gfp;
-}
-
-static inline struct page *alloc_hugepage_vma(int defrag,
- struct vm_area_struct *vma,
- unsigned long haddr, int nd,
- gfp_t extra_gfp)
-{
- return alloc_pages_vma(alloc_hugepage_gfpmask(defrag, extra_gfp),
- HPAGE_PMD_ORDER, vma, haddr, nd);
-}
-
#ifndef CONFIG_NUMA
static inline struct page *alloc_hugepage(int defrag)
{
diff --git a/mm/memory.c b/mm/memory.c
index 5f782d6..e6efd8c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -59,6 +59,7 @@
#include <linux/gfp.h>
#include <linux/migrate.h>
#include <linux/string.h>
+#include <linux/khugepaged.h>
#include <asm/io.h>
#include <asm/pgalloc.h>
@@ -3229,6 +3230,53 @@ oom:
return VM_FAULT_OOM;
}
+static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ unsigned long haddr = addr & HPAGE_PMD_MASK;
+
+ if (((vma->vm_start >> PAGE_SHIFT) & HPAGE_CACHE_INDEX_MASK) !=
+ (vma->vm_pgoff & HPAGE_CACHE_INDEX_MASK)) {
+ return false;
+ }
+ if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end) {
+ return false;
+ }
+ return true;
+}
+
+static struct page *alloc_fault_page_vma(struct vm_area_struct *vma,
+ unsigned long addr, unsigned int flags)
+{
+
+ if (flags & FAULT_FLAG_TRANSHUGE) {
+ struct page *page;
+ unsigned long haddr = addr & HPAGE_PMD_MASK;
+
+ page = alloc_hugepage_vma(transparent_hugepage_defrag(vma),
+ vma, haddr, numa_node_id(), 0);
+ if (page)
+ count_vm_event(THP_FAULT_ALLOC);
+ else
+ count_vm_event(THP_FAULT_FALLBACK);
+ return page;
+ }
+ return alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, addr);
+}
+
+static inline bool ptl_lock_and_check_entry(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long address, spinlock_t **ptl, pte_t **page_table,
+ pte_t orig_pte, unsigned int flags)
+{
+ if (flags & FAULT_FLAG_TRANSHUGE) {
+ spin_lock(&mm->page_table_lock);
+ return !pmd_none(*pmd);
+ } else {
+ *page_table = pte_offset_map_lock(mm, pmd, address, ptl);
+ return !pte_same(**page_table, orig_pte);
+ }
+}
+
/*
* __do_fault() tries to create a new page mapping. It aggressively
* tries to share with existing pages, but makes a separate copy if
@@ -3246,45 +3294,61 @@ static int __do_fault(struct mm_struct *mm, struct
vm_area_struct *vma,
unsigned long address, pmd_t *pmd,
pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
{
+ unsigned long haddr = address & PAGE_MASK;
pte_t *page_table;
spinlock_t *ptl;
- struct page *page;
- struct page *cow_page;
- pte_t entry;
- int anon = 0;
- struct page *dirty_page = NULL;
+ struct page *page, *cow_page, *dirty_page = NULL;
+ bool anon = false, page_mkwrite = false;
+ bool try_huge_pages = !!(flags & FAULT_FLAG_TRANSHUGE);
+ pgtable_t pgtable = NULL;
struct vm_fault vmf;
- int ret;
- int page_mkwrite = 0;
+ int nr = 1, ret;
+
+ if (try_huge_pages) {
+ if (!transhuge_vma_suitable(vma, haddr))
+ return VM_FAULT_FALLBACK;
+ if (unlikely(khugepaged_enter(vma)))
+ return VM_FAULT_OOM;
+ nr = HPAGE_PMD_NR;
+ haddr = address & HPAGE_PMD_MASK;
+ pgoff = linear_page_index(vma, haddr);
+ }
/*
* If we do COW later, allocate page befor taking lock_page()
* on the file cache page. This will reduce lock holding time.
*/
if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
-
if (unlikely(anon_vma_prepare(vma)))
return VM_FAULT_OOM;
- cow_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+ cow_page = alloc_fault_page_vma(vma, address, flags);
if (!cow_page)
- return VM_FAULT_OOM;
+ return VM_FAULT_OOM | VM_FAULT_FALLBACK;
if (mem_cgroup_newpage_charge(cow_page, mm, GFP_KERNEL)) {
page_cache_release(cow_page);
- return VM_FAULT_OOM;
+ return VM_FAULT_OOM | VM_FAULT_FALLBACK;
}
} else
cow_page = NULL;
- vmf.virtual_address = (void __user *)(address & PAGE_MASK);
+ vmf.virtual_address = (void __user *)haddr;
vmf.pgoff = pgoff;
vmf.flags = flags;
vmf.page = NULL;
- ret = vma->vm_ops->fault(vma, &vmf);
+ if (try_huge_pages) {
+ pgtable = pte_alloc_one(mm, haddr);
+ if (unlikely(!pgtable)) {
+ ret = VM_FAULT_OOM;
+ goto uncharge_out;
+ }
+ ret = vma->vm_ops->huge_fault(vma, &vmf);
+ } else
+ ret = vma->vm_ops->fault(vma, &vmf);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE |
- VM_FAULT_RETRY)))
+ VM_FAULT_RETRY | VM_FAULT_FALLBACK)))
goto uncharge_out;
if (unlikely(PageHWPoison(vmf.page))) {
@@ -3310,42 +3374,69 @@ static int __do_fault(struct mm_struct *mm, struct
vm_area_struct *vma,
if (flags & FAULT_FLAG_WRITE) {
if (!(vma->vm_flags & VM_SHARED)) {
page = cow_page;
- anon = 1;
- copy_user_highpage(page, vmf.page, address, vma);
+ anon = true;
+ if (try_huge_pages)
+ copy_user_highpage(page, vmf.page,
+ address, vma);
+ else
+ copy_user_huge_page(page, vmf.page, haddr, vma,
+ HPAGE_PMD_NR);
__SetPageUptodate(page);
- } else {
+ } else if (vma->vm_ops->page_mkwrite) {
/*
* If the page will be shareable, see if the backing
* address space wants to know that the page is about
* to become writable
*/
- if (vma->vm_ops->page_mkwrite) {
- int tmp;
-
- unlock_page(page);
- vmf.flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
- tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
- if (unlikely(tmp &
- (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
- ret = tmp;
+ int tmp;
+
+ unlock_page(page);
+ vmf.flags = FAULT_FLAG_WRITE | FAULT_FLAG_MKWRITE;
+ tmp = vma->vm_ops->page_mkwrite(vma, &vmf);
+ if (unlikely(tmp &
+ (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) {
+ ret = tmp;
+ goto unwritable_page;
+ }
+ if (unlikely(!(tmp & VM_FAULT_LOCKED))) {
+ lock_page(page);
+ if (!page->mapping) {
+ ret = 0; /* retry the fault */
+ unlock_page(page);
goto unwritable_page;
}
- if (unlikely(!(tmp & VM_FAULT_LOCKED))) {
- lock_page(page);
- if (!page->mapping) {
- ret = 0; /* retry the fault */
- unlock_page(page);
- goto unwritable_page;
- }
- } else
- VM_BUG_ON(!PageLocked(page));
- page_mkwrite = 1;
- }
+ } else
+ VM_BUG_ON(!PageLocked(page));
+ page_mkwrite = true;
}
+ }
+ if (unlikely(ptl_lock_and_check_entry(mm, pmd, address,
+ &ptl, &page_table, orig_pte, flags))) {
+ /* pte/pmd has changed. do not touch it */
+ if (pgtable)
+ pte_free(mm, pgtable);
+ if (cow_page)
+ mem_cgroup_uncharge_page(cow_page);
+ if (anon)
+ page_cache_release(page);
+ unlock_page(vmf.page);
+ page_cache_release(vmf.page);
+ return ret;
}
- page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+ flush_icache_page(vma, page);
+ if (anon) {
+ add_mm_counter_fast(mm, MM_ANONPAGES, nr);
+ page_add_new_anon_rmap(page, vma, address);
+ } else {
+ add_mm_counter_fast(mm, MM_FILEPAGES, nr);
+ page_add_file_rmap(page);
+ if (flags & FAULT_FLAG_WRITE) {
+ dirty_page = page;
+ get_page(dirty_page);
+ }
+ }
/*
* This silly early PAGE_DIRTY setting removes a race
@@ -3358,43 +3449,28 @@ static int __do_fault(struct mm_struct *mm, struct
vm_area_struct *vma,
* handle that later.
*/
/* Only go through if we didn't race with anybody else... */
- if (likely(pte_same(*page_table, orig_pte))) {
- flush_icache_page(vma, page);
- entry = mk_pte(page, vma->vm_page_prot);
+ if (try_huge_pages) {
+ pmd_t entry = mk_huge_pmd(page, vma->vm_page_prot);
if (flags & FAULT_FLAG_WRITE)
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- if (anon) {
- inc_mm_counter_fast(mm, MM_ANONPAGES);
- page_add_new_anon_rmap(page, vma, address);
- } else {
- inc_mm_counter_fast(mm, MM_FILEPAGES);
- page_add_file_rmap(page);
- if (flags & FAULT_FLAG_WRITE) {
- dirty_page = page;
- get_page(dirty_page);
- }
- }
- set_pte_at(mm, address, page_table, entry);
-
- /* no need to invalidate: a not-present page won't be cached */
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
+ set_pmd_at(mm, address, pmd, entry);
update_mmu_cache(vma, address, page_table);
+ spin_lock(&mm->page_table_lock);
} else {
- if (cow_page)
- mem_cgroup_uncharge_page(cow_page);
- if (anon)
- page_cache_release(page);
- else
- anon = 1; /* no anon but release faulted_page */
+ pte_t entry = mk_pte(page, vma->vm_page_prot);
+ if (flags & FAULT_FLAG_WRITE)
+ entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+ set_pte_at(mm, address, page_table, entry);
+ update_mmu_cache_pmd(vma, address, pmd);
+ pte_unmap_unlock(page_table, ptl);
}
- pte_unmap_unlock(page_table, ptl);
-
if (dirty_page) {
struct address_space *mapping = page->mapping;
- int dirtied = 0;
+ bool dirtied = false;
if (set_page_dirty(dirty_page))
- dirtied = 1;
+ dirtied = true;
unlock_page(dirty_page);
put_page(dirty_page);
if ((dirtied || page_mkwrite) && mapping) {
@@ -3413,13 +3489,16 @@ static int __do_fault(struct mm_struct *mm, struct
vm_area_struct *vma,
if (anon)
page_cache_release(vmf.page);
}
-
return ret;
unwritable_page:
+ if (pgtable)
+ pte_free(mm, pgtable);
page_cache_release(page);
return ret;
uncharge_out:
+ if (pgtable)
+ pte_free(mm, pgtable);
/* fs's fault handler get error */
if (cow_page) {
mem_cgroup_uncharge_page(cow_page);
--
Kirill A. Shutemov
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