The page is already alloc at ion_alloc function, ion_mmap map the alloced pages to user-space.
The default prot can be PTE_RDONLY. Take a look at here: set_pte_at() arch/arm64/include/asm: if (pte_dirty(pte) && pte_write(pte)) pte_val(pte) &= ~PTE_RDONLY; else pte_val(pte) |= PTE_RDONLY;
So with the dirty bit,it can improve the efficiency and donnot need to handle memory fault when use access.
Signed-off-by: Chen Feng puck.chen@hisilicon.com Signed-off-by: Wei Dong weidong2@hisilicon.com Reviewed-by: Zhuangluan Su suzhuangluan@hisilicon.com --- drivers/staging/android/ion/ion.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index e237e9f..dba5942 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -1026,6 +1026,9 @@ static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) if (!(buffer->flags & ION_FLAG_CACHED)) vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+ /*Default writeable*/ + vma->vm_page_prot = pte_mkdirty(vma->vm_page_prot); + mutex_lock(&buffer->lock); /* now map it to userspace */ ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma);
Hi Chen,
[auto build test ERROR on staging/staging-testing] [also build test ERROR on v4.4 next-20160114] [if your patch is applied to the wrong git tree, please drop us a note to help improving the system]
url: https://github.com/0day-ci/linux/commits/Chen-Feng/staging-ion-make-the-pte-... config: x86_64-randconfig-x013-01140842 (attached as .config) reproduce: # save the attached .config to linux build tree make ARCH=x86_64
All errors (new ones prefixed by >>):
drivers/staging/android/ion/ion.c: In function 'ion_mmap':
drivers/staging/android/ion/ion.c:1030:34: error: incompatible type for argument 1 of 'pte_mkdirty'
vma->vm_page_prot = pte_mkdirty(vma->vm_page_prot); ^ In file included from include/linux/mm.h:55:0, from include/linux/memblock.h:18, from drivers/staging/android/ion/ion.c:26: arch/x86/include/asm/pgtable.h:218:21: note: expected 'pte_t {aka struct <anonymous>}' but argument is of type 'pgprot_t {aka struct pgprot}' static inline pte_t pte_mkdirty(pte_t pte) ^
vim +/pte_mkdirty +1030 drivers/staging/android/ion/ion.c
1024 } 1025 1026 if (!(buffer->flags & ION_FLAG_CACHED)) 1027 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); 1028 1029 /*Default writeable*/
1030 vma->vm_page_prot = pte_mkdirty(vma->vm_page_prot);
1031 1032 mutex_lock(&buffer->lock); 1033 /* now map it to userspace */
--- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi Chen,
[auto build test ERROR on staging/staging-testing] [also build test ERROR on v4.4 next-20160114] [if your patch is applied to the wrong git tree, please drop us a note to help improving the system]
url: https://github.com/0day-ci/linux/commits/Chen-Feng/staging-ion-make-the-pte-... config: ia64-allyesconfig (attached as .config) reproduce: wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/ma... -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=ia64
All error/warnings (new ones prefixed by >>):
In file included from arch/ia64/include/asm/ptrace.h:45:0, from arch/ia64/include/asm/processor.h:19, from include/linux/mutex.h:19, from include/linux/kernfs.h:13, from include/linux/sysfs.h:15, from include/linux/kobject.h:21, from include/linux/device.h:17, from drivers/staging/android/ion/ion.c:18: drivers/staging/android/ion/ion.c: In function 'ion_mmap':
arch/ia64/include/asm/page.h:183:25: error: 'pgprot_t' has no member named 'pte'
# define pte_val(x) ((x).pte) ^ arch/ia64/include/asm/page.h:191:31: note: in definition of macro '__pte' # define __pte(x) ((pte_t) { (x) } ) ^
arch/ia64/include/asm/pgtable.h:311:33: note: in expansion of macro 'pte_val'
#define pte_mkdirty(pte) (__pte(pte_val(pte) | _PAGE_D)) ^
drivers/staging/android/ion/ion.c:1030:22: note: in expansion of macro 'pte_mkdirty'
vma->vm_page_prot = pte_mkdirty(vma->vm_page_prot); ^
vim +/pte_mkdirty +1030 drivers/staging/android/ion/ion.c
1014 return -EINVAL; 1015 } 1016 1017 if (ion_buffer_fault_user_mappings(buffer)) { 1018 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | 1019 VM_DONTDUMP; 1020 vma->vm_private_data = buffer; 1021 vma->vm_ops = &ion_vma_ops; 1022 ion_vm_open(vma); 1023 return 0; 1024 } 1025 1026 if (!(buffer->flags & ION_FLAG_CACHED)) 1027 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); 1028 1029 /*Default writeable*/
1030 vma->vm_page_prot = pte_mkdirty(vma->vm_page_prot);
1031 1032 mutex_lock(&buffer->lock); 1033 /* now map it to userspace */ 1034 ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma); 1035 mutex_unlock(&buffer->lock); 1036 1037 if (ret) 1038 pr_err("%s: failure mapping buffer to userspace\n",
--- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
(adding linux-arm and a few people)
On 01/14/2016 06:42 PM, Chen Feng wrote:
The page is already alloc at ion_alloc function, ion_mmap map the alloced pages to user-space.
The default prot can be PTE_RDONLY. Take a look at here: set_pte_at() arch/arm64/include/asm: if (pte_dirty(pte) && pte_write(pte)) pte_val(pte) &= ~PTE_RDONLY; else pte_val(pte) |= PTE_RDONLY;
So with the dirty bit,it can improve the efficiency and donnot need to handle memory fault when use access.
Signed-off-by: Chen Feng puck.chen@hisilicon.com Signed-off-by: Wei Dong weidong2@hisilicon.com Reviewed-by: Zhuangluan Su suzhuangluan@hisilicon.com
drivers/staging/android/ion/ion.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index e237e9f..dba5942 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -1026,6 +1026,9 @@ static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) if (!(buffer->flags & ION_FLAG_CACHED)) vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
- /*Default writeable*/
- vma->vm_page_prot = pte_mkdirty(vma->vm_page_prot);
- mutex_lock(&buffer->lock); /* now map it to userspace */ ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma);
The extra fault is unfortunate but I'm skeptical about just setting pte_mkdirty.
Catalin/Will, do you have any thoughts? Right now it seems like any range mapped with remap_pfn_range will have this extra fault behavior. Is marking the range dirty the best solution?
Thanks, Laura
On Fri, Jan 15, 2016 at 03:03:42PM -0800, Laura Abbott wrote:
(adding linux-arm and a few people)
On 01/14/2016 06:42 PM, Chen Feng wrote:
The page is already alloc at ion_alloc function, ion_mmap map the alloced pages to user-space.
The default prot can be PTE_RDONLY. Take a look at here: set_pte_at() arch/arm64/include/asm: if (pte_dirty(pte) && pte_write(pte)) pte_val(pte) &= ~PTE_RDONLY; else pte_val(pte) |= PTE_RDONLY;
So with the dirty bit,it can improve the efficiency and donnot need to handle memory fault when use access.
Signed-off-by: Chen Feng puck.chen@hisilicon.com Signed-off-by: Wei Dong weidong2@hisilicon.com Reviewed-by: Zhuangluan Su suzhuangluan@hisilicon.com
drivers/staging/android/ion/ion.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index e237e9f..dba5942 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -1026,6 +1026,9 @@ static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) if (!(buffer->flags & ION_FLAG_CACHED)) vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
- /*Default writeable*/
- vma->vm_page_prot = pte_mkdirty(vma->vm_page_prot);
- mutex_lock(&buffer->lock); /* now map it to userspace */ ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma);
The extra fault is unfortunate but I'm skeptical about just setting pte_mkdirty.
Catalin/Will, do you have any thoughts? Right now it seems like any range mapped with remap_pfn_range will have this extra fault behavior. Is marking the range dirty the best solution?
What happens if the mapping requested was read only - at the very least, I don't think this should be done unconditionally.
On 2016/1/16 7:23, Russell King - ARM Linux wrote:
On Fri, Jan 15, 2016 at 03:03:42PM -0800, Laura Abbott wrote:
(adding linux-arm and a few people)
On 01/14/2016 06:42 PM, Chen Feng wrote:
The page is already alloc at ion_alloc function, ion_mmap map the alloced pages to user-space.
The default prot can be PTE_RDONLY. Take a look at here: set_pte_at() arch/arm64/include/asm: if (pte_dirty(pte) && pte_write(pte)) pte_val(pte) &= ~PTE_RDONLY; else pte_val(pte) |= PTE_RDONLY;
So with the dirty bit,it can improve the efficiency and donnot need to handle memory fault when use access.
Signed-off-by: Chen Feng puck.chen@hisilicon.com Signed-off-by: Wei Dong weidong2@hisilicon.com Reviewed-by: Zhuangluan Su suzhuangluan@hisilicon.com
drivers/staging/android/ion/ion.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index e237e9f..dba5942 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -1026,6 +1026,9 @@ static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) if (!(buffer->flags & ION_FLAG_CACHED)) vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
- /*Default writeable*/
- vma->vm_page_prot = pte_mkdirty(vma->vm_page_prot);
- mutex_lock(&buffer->lock); /* now map it to userspace */ ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma);
The extra fault is unfortunate but I'm skeptical about just setting pte_mkdirty.
Catalin/Will, do you have any thoughts? Right now it seems like any range mapped with remap_pfn_range will have this extra fault behavior. Is marking the range dirty the best solution?
Laura Abbott,
I agree with you, it seems all the remap_pfn_range have this fault behavior.
What happens if the mapping requested was read only - at the very least, I don't think this should be done unconditionally.
Russell, I am not sure about doing this unconditionally, but it can waste memory&time while handling page fault with ion alloced page.
And the page can be used directly.
-
Chen Feng -
chenfeng
-
kbuild test robot -
Laura Abbott -
Russell King - ARM Linux