diff mbox series

[11/46] hugetlb: add hugetlb_pte to track HugeTLB page table entries

Message ID 20230105101844.1893104-12-jthoughton@google.com (mailing list archive)
State New
Headers show
Series Based on latest mm-unstable (85b44c25cd1e). | expand

Commit Message

James Houghton Jan. 5, 2023, 10:18 a.m. UTC 
After high-granularity mapping, page table entries for HugeTLB pages can
be of any size/type. (For example, we can have a 1G page mapped with a
mix of PMDs and PTEs.) This struct is to help keep track of a HugeTLB
PTE after we have done a page table walk.

Without this, we'd have to pass around the "size" of the PTE everywhere.
We effectively did this before; it could be fetched from the hstate,
which we pass around pretty much everywhere.

hugetlb_pte_present_leaf is included here as a helper function that will
be used frequently later on.

Signed-off-by: James Houghton <jthoughton@google.com>
---
 include/linux/hugetlb.h | 72 +++++++++++++++++++++++++++++++++++++++++
 mm/hugetlb.c            | 29 +++++++++++++++++
 2 files changed, 101 insertions(+)

Comments

kernel test robot Jan. 5, 2023, 4:06 p.m. UTC | #1 
Hi James,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on next-20230105]
[cannot apply to kvm/queue shuah-kselftest/next shuah-kselftest/fixes arnd-asm-generic/master linus/master kvm/linux-next v6.2-rc2 v6.2-rc1 v6.1 v6.2-rc2]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/James-Houghton/hugetlb-don-t-set-PageUptodate-for-UFFDIO_CONTINUE/20230105-182428
patch link:    https://lore.kernel.org/r/20230105101844.1893104-12-jthoughton%40google.com
patch subject: [PATCH 11/46] hugetlb: add hugetlb_pte to track HugeTLB page table entries
config: m68k-allmodconfig
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/2f657c22d05e0d32f2dfb41cb3a79a705bd9e37c
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review James-Houghton/hugetlb-don-t-set-PageUptodate-for-UFFDIO_CONTINUE/20230105-182428
        git checkout 2f657c22d05e0d32f2dfb41cb3a79a705bd9e37c
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash kernel/ mm/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

   In file included from include/linux/migrate.h:8,
                    from mm/zsmalloc.c:60:
>> include/linux/hugetlb.h:1284:40: warning: 'struct hugetlb_pte' declared inside parameter list will not be visible outside of this definition or declaration
    1284 | spinlock_t *hugetlb_pte_lockptr(struct hugetlb_pte *hpte)
         |                                        ^~~~~~~~~~~
   include/linux/hugetlb.h: In function 'hugetlb_pte_lockptr':
>> include/linux/hugetlb.h:1286:20: error: invalid use of undefined type 'struct hugetlb_pte'
    1286 |         return hpte->ptl;
         |                    ^~
   include/linux/hugetlb.h: At top level:
   include/linux/hugetlb.h:1290:37: warning: 'struct hugetlb_pte' declared inside parameter list will not be visible outside of this definition or declaration
    1290 | spinlock_t *hugetlb_pte_lock(struct hugetlb_pte *hpte)
         |                                     ^~~~~~~~~~~
   include/linux/hugetlb.h: In function 'hugetlb_pte_lock':
>> include/linux/hugetlb.h:1292:47: error: passing argument 1 of 'hugetlb_pte_lockptr' from incompatible pointer type [-Werror=incompatible-pointer-types]
    1292 |         spinlock_t *ptl = hugetlb_pte_lockptr(hpte);
         |                                               ^~~~
         |                                               |
         |                                               struct hugetlb_pte *
   include/linux/hugetlb.h:1284:53: note: expected 'struct hugetlb_pte *' but argument is of type 'struct hugetlb_pte *'
    1284 | spinlock_t *hugetlb_pte_lockptr(struct hugetlb_pte *hpte)
         |                                 ~~~~~~~~~~~~~~~~~~~~^~~~
   include/linux/hugetlb.h: At top level:
   include/linux/hugetlb.h:1301:32: warning: 'enum hugetlb_level' declared inside parameter list will not be visible outside of this definition or declaration
    1301 |                           enum hugetlb_level level)
         |                                ^~~~~~~~~~~~~
   include/linux/hugetlb.h:1299:56: warning: 'struct hugetlb_pte' declared inside parameter list will not be visible outside of this definition or declaration
    1299 | void hugetlb_pte_populate(struct mm_struct *mm, struct hugetlb_pte *hpte,
         |                                                        ^~~~~~~~~~~
>> include/linux/hugetlb.h:1301:46: error: parameter 5 ('level') has incomplete type
    1301 |                           enum hugetlb_level level)
         |                           ~~~~~~~~~~~~~~~~~~~^~~~~
>> include/linux/hugetlb.h:1299:6: error: function declaration isn't a prototype [-Werror=strict-prototypes]
    1299 | void hugetlb_pte_populate(struct mm_struct *mm, struct hugetlb_pte *hpte,
         |      ^~~~~~~~~~~~~~~~~~~~
   include/linux/hugetlb.h: In function 'hugetlb_pte_populate':
>> include/linux/hugetlb.h:1303:9: error: implicit declaration of function '__hugetlb_pte_populate'; did you mean 'hugetlb_pte_populate'? [-Werror=implicit-function-declaration]
    1303 |         __hugetlb_pte_populate(hpte, ptep, shift, level,
         |         ^~~~~~~~~~~~~~~~~~~~~~
         |         hugetlb_pte_populate
   cc1: some warnings being treated as errors
--
   In file included from kernel/fork.c:52:
>> include/linux/hugetlb.h:1284:40: warning: 'struct hugetlb_pte' declared inside parameter list will not be visible outside of this definition or declaration
    1284 | spinlock_t *hugetlb_pte_lockptr(struct hugetlb_pte *hpte)
         |                                        ^~~~~~~~~~~
   include/linux/hugetlb.h: In function 'hugetlb_pte_lockptr':
>> include/linux/hugetlb.h:1286:20: error: invalid use of undefined type 'struct hugetlb_pte'
    1286 |         return hpte->ptl;
         |                    ^~
   include/linux/hugetlb.h: At top level:
   include/linux/hugetlb.h:1290:37: warning: 'struct hugetlb_pte' declared inside parameter list will not be visible outside of this definition or declaration
    1290 | spinlock_t *hugetlb_pte_lock(struct hugetlb_pte *hpte)
         |                                     ^~~~~~~~~~~
   include/linux/hugetlb.h: In function 'hugetlb_pte_lock':
>> include/linux/hugetlb.h:1292:47: error: passing argument 1 of 'hugetlb_pte_lockptr' from incompatible pointer type [-Werror=incompatible-pointer-types]
    1292 |         spinlock_t *ptl = hugetlb_pte_lockptr(hpte);
         |                                               ^~~~
         |                                               |
         |                                               struct hugetlb_pte *
   include/linux/hugetlb.h:1284:53: note: expected 'struct hugetlb_pte *' but argument is of type 'struct hugetlb_pte *'
    1284 | spinlock_t *hugetlb_pte_lockptr(struct hugetlb_pte *hpte)
         |                                 ~~~~~~~~~~~~~~~~~~~~^~~~
   include/linux/hugetlb.h: At top level:
   include/linux/hugetlb.h:1301:32: warning: 'enum hugetlb_level' declared inside parameter list will not be visible outside of this definition or declaration
    1301 |                           enum hugetlb_level level)
         |                                ^~~~~~~~~~~~~
   include/linux/hugetlb.h:1299:56: warning: 'struct hugetlb_pte' declared inside parameter list will not be visible outside of this definition or declaration
    1299 | void hugetlb_pte_populate(struct mm_struct *mm, struct hugetlb_pte *hpte,
         |                                                        ^~~~~~~~~~~
>> include/linux/hugetlb.h:1301:46: error: parameter 5 ('level') has incomplete type
    1301 |                           enum hugetlb_level level)
         |                           ~~~~~~~~~~~~~~~~~~~^~~~~
>> include/linux/hugetlb.h:1299:6: error: function declaration isn't a prototype [-Werror=strict-prototypes]
    1299 | void hugetlb_pte_populate(struct mm_struct *mm, struct hugetlb_pte *hpte,
         |      ^~~~~~~~~~~~~~~~~~~~
   include/linux/hugetlb.h: In function 'hugetlb_pte_populate':
>> include/linux/hugetlb.h:1303:9: error: implicit declaration of function '__hugetlb_pte_populate'; did you mean 'hugetlb_pte_populate'? [-Werror=implicit-function-declaration]
    1303 |         __hugetlb_pte_populate(hpte, ptep, shift, level,
         |         ^~~~~~~~~~~~~~~~~~~~~~
         |         hugetlb_pte_populate
   kernel/fork.c: At top level:
   kernel/fork.c:162:13: warning: no previous prototype for 'arch_release_task_struct' [-Wmissing-prototypes]
     162 | void __weak arch_release_task_struct(struct task_struct *tsk)
         |             ^~~~~~~~~~~~~~~~~~~~~~~~
   kernel/fork.c:862:20: warning: no previous prototype for 'arch_task_cache_init' [-Wmissing-prototypes]
     862 | void __init __weak arch_task_cache_init(void) { }
         |                    ^~~~~~~~~~~~~~~~~~~~
   kernel/fork.c:957:12: warning: no previous prototype for 'arch_dup_task_struct' [-Wmissing-prototypes]
     957 | int __weak arch_dup_task_struct(struct task_struct *dst,
         |            ^~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors
--
   In file included from mm/madvise.c:16:
>> include/linux/hugetlb.h:1284:40: warning: 'struct hugetlb_pte' declared inside parameter list will not be visible outside of this definition or declaration
    1284 | spinlock_t *hugetlb_pte_lockptr(struct hugetlb_pte *hpte)
         |                                        ^~~~~~~~~~~
   include/linux/hugetlb.h: In function 'hugetlb_pte_lockptr':
>> include/linux/hugetlb.h:1286:20: error: invalid use of undefined type 'struct hugetlb_pte'
    1286 |         return hpte->ptl;
         |                    ^~
   include/linux/hugetlb.h: At top level:
   include/linux/hugetlb.h:1290:37: warning: 'struct hugetlb_pte' declared inside parameter list will not be visible outside of this definition or declaration
    1290 | spinlock_t *hugetlb_pte_lock(struct hugetlb_pte *hpte)
         |                                     ^~~~~~~~~~~
   include/linux/hugetlb.h: In function 'hugetlb_pte_lock':
>> include/linux/hugetlb.h:1292:47: error: passing argument 1 of 'hugetlb_pte_lockptr' from incompatible pointer type [-Werror=incompatible-pointer-types]
    1292 |         spinlock_t *ptl = hugetlb_pte_lockptr(hpte);
         |                                               ^~~~
         |                                               |
         |                                               struct hugetlb_pte *
   include/linux/hugetlb.h:1284:53: note: expected 'struct hugetlb_pte *' but argument is of type 'struct hugetlb_pte *'
    1284 | spinlock_t *hugetlb_pte_lockptr(struct hugetlb_pte *hpte)
         |                                 ~~~~~~~~~~~~~~~~~~~~^~~~
   include/linux/hugetlb.h: At top level:
   include/linux/hugetlb.h:1301:32: warning: 'enum hugetlb_level' declared inside parameter list will not be visible outside of this definition or declaration
    1301 |                           enum hugetlb_level level)
         |                                ^~~~~~~~~~~~~
   include/linux/hugetlb.h:1299:56: warning: 'struct hugetlb_pte' declared inside parameter list will not be visible outside of this definition or declaration
    1299 | void hugetlb_pte_populate(struct mm_struct *mm, struct hugetlb_pte *hpte,
         |                                                        ^~~~~~~~~~~
>> include/linux/hugetlb.h:1301:46: error: parameter 5 ('level') has incomplete type
    1301 |                           enum hugetlb_level level)
         |                           ~~~~~~~~~~~~~~~~~~~^~~~~
>> include/linux/hugetlb.h:1299:6: error: function declaration isn't a prototype [-Werror=strict-prototypes]
    1299 | void hugetlb_pte_populate(struct mm_struct *mm, struct hugetlb_pte *hpte,
         |      ^~~~~~~~~~~~~~~~~~~~
   include/linux/hugetlb.h: In function 'hugetlb_pte_populate':
>> include/linux/hugetlb.h:1303:9: error: implicit declaration of function '__hugetlb_pte_populate'; did you mean 'hugetlb_pte_populate'? [-Werror=implicit-function-declaration]
    1303 |         __hugetlb_pte_populate(hpte, ptep, shift, level,
         |         ^~~~~~~~~~~~~~~~~~~~~~
         |         hugetlb_pte_populate
   mm/madvise.c: In function 'madvise_split':
   mm/madvise.c:1023:9: error: implicit declaration of function 'hugetlb_vma_lock_alloc'; did you mean 'hugetlb_vma_lock_write'? [-Werror=implicit-function-declaration]
    1023 |         hugetlb_vma_lock_alloc(vma);
         |         ^~~~~~~~~~~~~~~~~~~~~~
         |         hugetlb_vma_lock_write
   cc1: some warnings being treated as errors


vim +1286 include/linux/hugetlb.h

  1282	
  1283	static inline
> 1284	spinlock_t *hugetlb_pte_lockptr(struct hugetlb_pte *hpte)
  1285	{
> 1286		return hpte->ptl;
  1287	}
  1288	
  1289	static inline
  1290	spinlock_t *hugetlb_pte_lock(struct hugetlb_pte *hpte)
  1291	{
> 1292		spinlock_t *ptl = hugetlb_pte_lockptr(hpte);
  1293	
  1294		spin_lock(ptl);
  1295		return ptl;
  1296	}
  1297	
  1298	static inline
> 1299	void hugetlb_pte_populate(struct mm_struct *mm, struct hugetlb_pte *hpte,
  1300				  pte_t *ptep, unsigned int shift,
> 1301				  enum hugetlb_level level)
  1302	{
> 1303		__hugetlb_pte_populate(hpte, ptep, shift, level,
  1304				huge_pte_lockptr(shift, mm, ptep));
  1305	}
  1306
diff mbox series

Patch

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 3f098363cd6e..bf441d8a1b52 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -38,6 +38,54 @@  typedef struct { unsigned long pd; } hugepd_t;
  */
 #define __NR_USED_SUBPAGE 3
 
+enum hugetlb_level {
+	HUGETLB_LEVEL_PTE = 1,
+	/*
+	 * We always include PMD, PUD, and P4D in this enum definition so that,
+	 * when logged as an integer, we can easily tell which level it is.
+	 */
+	HUGETLB_LEVEL_PMD,
+	HUGETLB_LEVEL_PUD,
+	HUGETLB_LEVEL_P4D,
+	HUGETLB_LEVEL_PGD,
+};
+
+struct hugetlb_pte {
+	pte_t *ptep;
+	unsigned int shift;
+	enum hugetlb_level level;
+	spinlock_t *ptl;
+};
+
+static inline
+void __hugetlb_pte_populate(struct hugetlb_pte *hpte, pte_t *ptep,
+			    unsigned int shift, enum hugetlb_level level,
+			    spinlock_t *ptl)
+{
+	/*
+	 * If 'shift' indicates that this PTE is contiguous, then @ptep must
+	 * be the first pte of the contiguous bunch.
+	 */
+	hpte->ptl = ptl;
+	hpte->ptep = ptep;
+	hpte->shift = shift;
+	hpte->level = level;
+}
+
+static inline
+unsigned long hugetlb_pte_size(const struct hugetlb_pte *hpte)
+{
+	return 1UL << hpte->shift;
+}
+
+static inline
+unsigned long hugetlb_pte_mask(const struct hugetlb_pte *hpte)
+{
+	return ~(hugetlb_pte_size(hpte) - 1);
+}
+
+bool hugetlb_pte_present_leaf(const struct hugetlb_pte *hpte, pte_t pte);
+
 struct hugepage_subpool {
 	spinlock_t lock;
 	long count;
@@ -1232,6 +1280,30 @@  static inline spinlock_t *huge_pte_lock(struct hstate *h,
 	return ptl;
 }
 
+static inline
+spinlock_t *hugetlb_pte_lockptr(struct hugetlb_pte *hpte)
+{
+	return hpte->ptl;
+}
+
+static inline
+spinlock_t *hugetlb_pte_lock(struct hugetlb_pte *hpte)
+{
+	spinlock_t *ptl = hugetlb_pte_lockptr(hpte);
+
+	spin_lock(ptl);
+	return ptl;
+}
+
+static inline
+void hugetlb_pte_populate(struct mm_struct *mm, struct hugetlb_pte *hpte,
+			  pte_t *ptep, unsigned int shift,
+			  enum hugetlb_level level)
+{
+	__hugetlb_pte_populate(hpte, ptep, shift, level,
+			huge_pte_lockptr(shift, mm, ptep));
+}
+
 #if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_CMA)
 extern void __init hugetlb_cma_reserve(int order);
 #else
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4db38dc79d0e..2d83a2c359a2 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1266,6 +1266,35 @@  static bool vma_has_reserves(struct vm_area_struct *vma, long chg)
 	return false;
 }
 
+bool hugetlb_pte_present_leaf(const struct hugetlb_pte *hpte, pte_t pte)
+{
+	pgd_t pgd;
+	p4d_t p4d;
+	pud_t pud;
+	pmd_t pmd;
+
+	switch (hpte->level) {
+	case HUGETLB_LEVEL_PGD:
+		pgd = __pgd(pte_val(pte));
+		return pgd_present(pgd) && pgd_leaf(pgd);
+	case HUGETLB_LEVEL_P4D:
+		p4d = __p4d(pte_val(pte));
+		return p4d_present(p4d) && p4d_leaf(p4d);
+	case HUGETLB_LEVEL_PUD:
+		pud = __pud(pte_val(pte));
+		return pud_present(pud) && pud_leaf(pud);
+	case HUGETLB_LEVEL_PMD:
+		pmd = __pmd(pte_val(pte));
+		return pmd_present(pmd) && pmd_leaf(pmd);
+	case HUGETLB_LEVEL_PTE:
+		return pte_present(pte);
+	default:
+		WARN_ON_ONCE(1);
+		return false;
+	}
+}
+
+
 static void enqueue_hugetlb_folio(struct hstate *h, struct folio *folio)
 {
 	int nid = folio_nid(folio);