Patchwork [4/5] powerpc/mmu: use pinned_vm instead of locked_vm to account pinned pages

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Submitter Daniel Jordan
Date Feb. 11, 2019, 10:44 p.m.
Message ID <20190211224437.25267-5-daniel.m.jordan@oracle.com>
Download mbox | patch
Permalink /patch/723355/
State New
Headers show

Comments

Daniel Jordan - Feb. 11, 2019, 10:44 p.m.
Beginning with bc3e53f682d9 ("mm: distinguish between mlocked and pinned
pages"), locked and pinned pages are accounted separately.  The IOMMU
MMU helpers on powerpc account pinned pages to locked_vm; use pinned_vm
instead.

pinned_vm recently became atomic and so no longer relies on mmap_sem
held as writer: delete.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
---
 arch/powerpc/mm/mmu_context_iommu.c | 43 ++++++++++++++---------------
 1 file changed, 21 insertions(+), 22 deletions(-)
kbuild test robot - Feb. 13, 2019, 1:14 a.m.
Hi Daniel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on vfio/next]
[also build test ERROR on v5.0-rc4]
[cannot apply to next-20190212]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Daniel-Jordan/use-pinned_vm-instead-of-locked_vm-to-account-pinned-pages/20190213-070458
base:   https://github.com/awilliam/linux-vfio.git next
config: powerpc-defconfig (attached as .config)
compiler: powerpc64-linux-gnu-gcc (Debian 8.2.0-11) 8.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=8.2.0 make.cross ARCH=powerpc 

All errors (new ones prefixed by >>):

   In file included from include/linux/rcupdate.h:38,
                    from include/linux/rculist.h:11,
                    from include/linux/sched/signal.h:5,
                    from arch/powerpc/mm/mmu_context_iommu.c:13:
   arch/powerpc/mm/mmu_context_iommu.c: In function 'mm_iommu_adjust_pinned_vm':
>> arch/powerpc/mm/mmu_context_iommu.c:55:43: error: passing argument 2 of 'atomic64_add_return_relaxed' from incompatible pointer type [-Werror=incompatible-pointer-types]
      pinned_vm = atomic64_add_return(npages, &mm->pinned_vm);
                                              ^~~~~~~~~~~~~~
   include/linux/atomic.h:75:22: note: in definition of macro '__atomic_op_fence'
     typeof(op##_relaxed(args)) __ret;    \
                         ^~~~
   arch/powerpc/mm/mmu_context_iommu.c:55:15: note: in expansion of macro 'atomic64_add_return'
      pinned_vm = atomic64_add_return(npages, &mm->pinned_vm);
                  ^~~~~~~~~~~~~~~~~~~
   In file included from include/linux/atomic.h:7,
                    from include/linux/rcupdate.h:38,
                    from include/linux/rculist.h:11,
                    from include/linux/sched/signal.h:5,
                    from arch/powerpc/mm/mmu_context_iommu.c:13:
   arch/powerpc/include/asm/atomic.h:331:52: note: expected 'atomic64_t *' {aka 'struct <anonymous> *'} but argument is of type 'long unsigned int *'
    atomic64_##op##_return_relaxed(long a, atomic64_t *v)   \
                                           ~~~~~~~~~~~~^
   arch/powerpc/include/asm/atomic.h:367:2: note: in expansion of macro 'ATOMIC64_OP_RETURN_RELAXED'
     ATOMIC64_OP_RETURN_RELAXED(op, asm_op)    \
     ^~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/atomic.h:370:1: note: in expansion of macro 'ATOMIC64_OPS'
    ATOMIC64_OPS(add, add)
    ^~~~~~~~~~~~
   In file included from include/linux/rcupdate.h:38,
                    from include/linux/rculist.h:11,
                    from include/linux/sched/signal.h:5,
                    from arch/powerpc/mm/mmu_context_iommu.c:13:
>> arch/powerpc/mm/mmu_context_iommu.c:55:43: error: passing argument 2 of 'atomic64_add_return_relaxed' from incompatible pointer type [-Werror=incompatible-pointer-types]
      pinned_vm = atomic64_add_return(npages, &mm->pinned_vm);
                                              ^~~~~~~~~~~~~~
   include/linux/atomic.h:77:23: note: in definition of macro '__atomic_op_fence'
     __ret = op##_relaxed(args);     \
                          ^~~~
   arch/powerpc/mm/mmu_context_iommu.c:55:15: note: in expansion of macro 'atomic64_add_return'
      pinned_vm = atomic64_add_return(npages, &mm->pinned_vm);
                  ^~~~~~~~~~~~~~~~~~~
   In file included from include/linux/atomic.h:7,
                    from include/linux/rcupdate.h:38,
                    from include/linux/rculist.h:11,
                    from include/linux/sched/signal.h:5,
                    from arch/powerpc/mm/mmu_context_iommu.c:13:
   arch/powerpc/include/asm/atomic.h:331:52: note: expected 'atomic64_t *' {aka 'struct <anonymous> *'} but argument is of type 'long unsigned int *'
    atomic64_##op##_return_relaxed(long a, atomic64_t *v)   \
                                           ~~~~~~~~~~~~^
   arch/powerpc/include/asm/atomic.h:367:2: note: in expansion of macro 'ATOMIC64_OP_RETURN_RELAXED'
     ATOMIC64_OP_RETURN_RELAXED(op, asm_op)    \
     ^~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/atomic.h:370:1: note: in expansion of macro 'ATOMIC64_OPS'
    ATOMIC64_OPS(add, add)
    ^~~~~~~~~~~~
>> arch/powerpc/mm/mmu_context_iommu.c:58:25: error: passing argument 2 of 'atomic64_sub' from incompatible pointer type [-Werror=incompatible-pointer-types]
       atomic64_sub(npages, &mm->pinned_vm);
                            ^~~~~~~~~~~~~~
   In file included from include/linux/atomic.h:7,
                    from include/linux/rcupdate.h:38,
                    from include/linux/rculist.h:11,
                    from include/linux/sched/signal.h:5,
                    from arch/powerpc/mm/mmu_context_iommu.c:13:
   arch/powerpc/include/asm/atomic.h:315:58: note: expected 'atomic64_t *' {aka 'struct <anonymous> *'} but argument is of type 'long unsigned int *'
    static __inline__ void atomic64_##op(long a, atomic64_t *v)  \
                                                 ~~~~~~~~~~~~^
   arch/powerpc/include/asm/atomic.h:366:2: note: in expansion of macro 'ATOMIC64_OP'
     ATOMIC64_OP(op, asm_op)      \
     ^~~~~~~~~~~
   arch/powerpc/include/asm/atomic.h:371:1: note: in expansion of macro 'ATOMIC64_OPS'
    ATOMIC64_OPS(sub, subf)
    ^~~~~~~~~~~~
>> arch/powerpc/mm/mmu_context_iommu.c:61:29: error: passing argument 1 of 'atomic64_read' from incompatible pointer type [-Werror=incompatible-pointer-types]
      pinned_vm = atomic64_read(&mm->pinned_vm);
                                ^~~~~~~~~~~~~~
   In file included from include/linux/atomic.h:7,
                    from include/linux/rcupdate.h:38,
                    from include/linux/rculist.h:11,
                    from include/linux/sched/signal.h:5,
                    from arch/powerpc/mm/mmu_context_iommu.c:13:
   arch/powerpc/include/asm/atomic.h:300:56: note: expected 'const atomic64_t *' {aka 'const struct <anonymous> *'} but argument is of type 'long unsigned int *'
    static __inline__ long atomic64_read(const atomic64_t *v)
                                         ~~~~~~~~~~~~~~~~~~^
   arch/powerpc/mm/mmu_context_iommu.c:64:24: error: passing argument 2 of 'atomic64_sub' from incompatible pointer type [-Werror=incompatible-pointer-types]
      atomic64_sub(npages, &mm->pinned_vm);
                           ^~~~~~~~~~~~~~
   In file included from include/linux/atomic.h:7,
                    from include/linux/rcupdate.h:38,
                    from include/linux/rculist.h:11,
                    from include/linux/sched/signal.h:5,
                    from arch/powerpc/mm/mmu_context_iommu.c:13:
   arch/powerpc/include/asm/atomic.h:315:58: note: expected 'atomic64_t *' {aka 'struct <anonymous> *'} but argument is of type 'long unsigned int *'
    static __inline__ void atomic64_##op(long a, atomic64_t *v)  \
                                                 ~~~~~~~~~~~~^
   arch/powerpc/include/asm/atomic.h:366:2: note: in expansion of macro 'ATOMIC64_OP'
     ATOMIC64_OP(op, asm_op)      \
     ^~~~~~~~~~~
   arch/powerpc/include/asm/atomic.h:371:1: note: in expansion of macro 'ATOMIC64_OPS'
    ATOMIC64_OPS(sub, subf)
    ^~~~~~~~~~~~
   In file included from include/linux/kernel.h:14,
                    from include/linux/list.h:9,
                    from include/linux/rculist.h:10,
                    from include/linux/sched/signal.h:5,
                    from arch/powerpc/mm/mmu_context_iommu.c:13:
   arch/powerpc/mm/mmu_context_iommu.c:70:18: error: passing argument 1 of 'atomic64_read' from incompatible pointer type [-Werror=incompatible-pointer-types]
       atomic64_read(&mm->pinned_vm) << PAGE_SHIFT,
                     ^~~~~~~~~~~~~~
   include/linux/printk.h:136:17: note: in definition of macro 'no_printk'
      printk(fmt, ##__VA_ARGS__);  \
                    ^~~~~~~~~~~
   arch/powerpc/mm/mmu_context_iommu.c:67:2: note: in expansion of macro 'pr_debug'
     pr_debug("[%d] RLIMIT_MEMLOCK HASH64 %c%lu %ld/%lu\n",
     ^~~~~~~~
   In file included from include/linux/atomic.h:7,
                    from include/linux/rcupdate.h:38,
                    from include/linux/rculist.h:11,
                    from include/linux/sched/signal.h:5,
                    from arch/powerpc/mm/mmu_context_iommu.c:13:
   arch/powerpc/include/asm/atomic.h:300:56: note: expected 'const atomic64_t *' {aka 'const struct <anonymous> *'} but argument is of type 'long unsigned int *'
    static __inline__ long atomic64_read(const atomic64_t *v)
                                         ~~~~~~~~~~~~~~~~~~^
   cc1: all warnings being treated as errors

vim +/atomic64_add_return_relaxed +55 arch/powerpc/mm/mmu_context_iommu.c

  > 13	#include <linux/sched/signal.h>
    14	#include <linux/slab.h>
    15	#include <linux/rculist.h>
    16	#include <linux/vmalloc.h>
    17	#include <linux/mutex.h>
    18	#include <linux/migrate.h>
    19	#include <linux/hugetlb.h>
    20	#include <linux/swap.h>
    21	#include <linux/sizes.h>
    22	#include <asm/mmu_context.h>
    23	#include <asm/pte-walk.h>
    24	
    25	static DEFINE_MUTEX(mem_list_mutex);
    26	
    27	#define MM_IOMMU_TABLE_GROUP_PAGE_DIRTY	0x1
    28	#define MM_IOMMU_TABLE_GROUP_PAGE_MASK	~(SZ_4K - 1)
    29	
    30	struct mm_iommu_table_group_mem_t {
    31		struct list_head next;
    32		struct rcu_head rcu;
    33		unsigned long used;
    34		atomic64_t mapped;
    35		unsigned int pageshift;
    36		u64 ua;			/* userspace address */
    37		u64 entries;		/* number of entries in hpas[] */
    38		u64 *hpas;		/* vmalloc'ed */
    39	#define MM_IOMMU_TABLE_INVALID_HPA	((uint64_t)-1)
    40		u64 dev_hpa;		/* Device memory base address */
    41	};
    42	
    43	static long mm_iommu_adjust_pinned_vm(struct mm_struct *mm,
    44			unsigned long npages, bool incr)
    45	{
    46		long ret = 0;
    47		unsigned long lock_limit;
    48		s64 pinned_vm;
    49	
    50		if (!npages)
    51			return 0;
    52	
    53		if (incr) {
    54			lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  > 55			pinned_vm = atomic64_add_return(npages, &mm->pinned_vm);
    56			if (pinned_vm > lock_limit && !capable(CAP_IPC_LOCK)) {
    57				ret = -ENOMEM;
  > 58				atomic64_sub(npages, &mm->pinned_vm);
    59			}
    60		} else {
  > 61			pinned_vm = atomic64_read(&mm->pinned_vm);
    62			if (WARN_ON_ONCE(npages > pinned_vm))
    63				npages = pinned_vm;
    64			atomic64_sub(npages, &mm->pinned_vm);
    65		}
    66	
    67		pr_debug("[%d] RLIMIT_MEMLOCK HASH64 %c%lu %ld/%lu\n",
    68				current ? current->pid : 0, incr ? '+' : '-',
    69				npages << PAGE_SHIFT,
    70				atomic64_read(&mm->pinned_vm) << PAGE_SHIFT,
    71				rlimit(RLIMIT_MEMLOCK));
    72	
    73		return ret;
    74	}
    75	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Patch

diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c
index a712a650a8b6..fdf670542847 100644
--- a/arch/powerpc/mm/mmu_context_iommu.c
+++ b/arch/powerpc/mm/mmu_context_iommu.c
@@ -40,36 +40,35 @@  struct mm_iommu_table_group_mem_t {
 	u64 dev_hpa;		/* Device memory base address */
 };
 
-static long mm_iommu_adjust_locked_vm(struct mm_struct *mm,
+static long mm_iommu_adjust_pinned_vm(struct mm_struct *mm,
 		unsigned long npages, bool incr)
 {
-	long ret = 0, locked, lock_limit;
+	long ret = 0;
+	unsigned long lock_limit;
+	s64 pinned_vm;
 
 	if (!npages)
 		return 0;
 
-	down_write(&mm->mmap_sem);
-
 	if (incr) {
-		locked = mm->locked_vm + npages;
 		lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-		if (locked > lock_limit && !capable(CAP_IPC_LOCK))
+		pinned_vm = atomic64_add_return(npages, &mm->pinned_vm);
+		if (pinned_vm > lock_limit && !capable(CAP_IPC_LOCK)) {
 			ret = -ENOMEM;
-		else
-			mm->locked_vm += npages;
+			atomic64_sub(npages, &mm->pinned_vm);
+		}
 	} else {
-		if (WARN_ON_ONCE(npages > mm->locked_vm))
-			npages = mm->locked_vm;
-		mm->locked_vm -= npages;
+		pinned_vm = atomic64_read(&mm->pinned_vm);
+		if (WARN_ON_ONCE(npages > pinned_vm))
+			npages = pinned_vm;
+		atomic64_sub(npages, &mm->pinned_vm);
 	}
 
-	pr_debug("[%d] RLIMIT_MEMLOCK HASH64 %c%ld %ld/%ld\n",
-			current ? current->pid : 0,
-			incr ? '+' : '-',
+	pr_debug("[%d] RLIMIT_MEMLOCK HASH64 %c%lu %ld/%lu\n",
+			current ? current->pid : 0, incr ? '+' : '-',
 			npages << PAGE_SHIFT,
-			mm->locked_vm << PAGE_SHIFT,
+			atomic64_read(&mm->pinned_vm) << PAGE_SHIFT,
 			rlimit(RLIMIT_MEMLOCK));
-	up_write(&mm->mmap_sem);
 
 	return ret;
 }
@@ -133,7 +132,7 @@  static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
 		struct mm_iommu_table_group_mem_t **pmem)
 {
 	struct mm_iommu_table_group_mem_t *mem;
-	long i, j, ret = 0, locked_entries = 0;
+	long i, j, ret = 0, pinned_entries = 0;
 	unsigned int pageshift;
 	unsigned long flags;
 	unsigned long cur_ua;
@@ -154,11 +153,11 @@  static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
 	}
 
 	if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) {
-		ret = mm_iommu_adjust_locked_vm(mm, entries, true);
+		ret = mm_iommu_adjust_pinned_vm(mm, entries, true);
 		if (ret)
 			goto unlock_exit;
 
-		locked_entries = entries;
+		pinned_entries = entries;
 	}
 
 	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
@@ -252,8 +251,8 @@  static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
 	list_add_rcu(&mem->next, &mm->context.iommu_group_mem_list);
 
 unlock_exit:
-	if (locked_entries && ret)
-		mm_iommu_adjust_locked_vm(mm, locked_entries, false);
+	if (pinned_entries && ret)
+		mm_iommu_adjust_pinned_vm(mm, pinned_entries, false);
 
 	mutex_unlock(&mem_list_mutex);
 
@@ -352,7 +351,7 @@  long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem)
 	mm_iommu_release(mem);
 
 	if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA)
-		mm_iommu_adjust_locked_vm(mm, entries, false);
+		mm_iommu_adjust_pinned_vm(mm, entries, false);
 
 unlock_exit:
 	mutex_unlock(&mem_list_mutex);