Re: [PATCH] ANDROID: binder: change down_write to down_read

2018-03-28 Thread Martijn Coenen
On Wed, Mar 28, 2018 at 4:42 AM, Minchan Kim wrote: > binder_update_page_range needs down_write of mmap_sem because > vm_insert_page need to change vma->vm_flags to VM_MIXEDMAP unless > it is set. However, when I profile binder working, it seems > every binder buffers should be mapped in advance b

Re: [PATCH] ANDROID: binder: change down_write to down_read

2018-03-27 Thread Minchan Kim
On Wed, Mar 28, 2018 at 07:53:54AM +0200, Greg Kroah-Hartman wrote: > On Wed, Mar 28, 2018 at 11:42:31AM +0900, Minchan Kim wrote: > > binder_update_page_range needs down_write of mmap_sem because > > vm_insert_page need to change vma->vm_flags to VM_MIXEDMAP unless > > it is set. However, when I p

Re: [PATCH] ANDROID: binder: change down_write to down_read

2018-03-27 Thread Greg Kroah-Hartman
On Wed, Mar 28, 2018 at 11:42:31AM +0900, Minchan Kim wrote: > binder_update_page_range needs down_write of mmap_sem because > vm_insert_page need to change vma->vm_flags to VM_MIXEDMAP unless > it is set. However, when I profile binder working, it seems > every binder buffers should be mapped in a

[PATCH] ANDROID: binder: change down_write to down_read

2018-03-27 Thread Minchan Kim
binder_update_page_range needs down_write of mmap_sem because vm_insert_page need to change vma->vm_flags to VM_MIXEDMAP unless it is set. However, when I profile binder working, it seems every binder buffers should be mapped in advance by binder_mmap. It means we could set VM_MIXEDMAP in bider_mma