This is a note to let you know that I've just added the patch titled android: binder: use VM_ALLOC to get vm area to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the char-misc-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From aac6830ec1cb681544212838911cdc57f2638216 Mon Sep 17 00:00:00 2001 From: Ganesh Mahendran <opensource.ganesh@xxxxxxxxx> Date: Wed, 10 Jan 2018 10:49:05 +0800 Subject: android: binder: use VM_ALLOC to get vm area VM_IOREMAP is used to access hardware through a mechanism called I/O mapped memory. Android binder is a IPC machanism which will not access I/O memory. And VM_IOREMAP has alignment requiement which may not needed in binder. __get_vm_area_node() { ... if (flags & VM_IOREMAP) align = 1ul << clamp_t(int, fls_long(size), PAGE_SHIFT, IOREMAP_MAX_ORDER); ... } This patch will save some kernel vm area, especially for 32bit os. In 32bit OS, kernel vm area is only 240MB. We may got below error when launching a app: <3>[ 4482.440053] binder_alloc: binder_alloc_mmap_handler: 15728 8ce67000-8cf65000 get_vm_area failed -12 <3>[ 4483.218817] binder_alloc: binder_alloc_mmap_handler: 15745 8ce67000-8cf65000 get_vm_area failed -12 Signed-off-by: Ganesh Mahendran <opensource.ganesh@xxxxxxxxx> Acked-by: Martijn Coenen <maco@xxxxxxxxxxx> Acked-by: Todd Kjos <tkjos@xxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> ---- V3: update comments V2: update comments Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/android/binder_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 07b866afee54..5a426c877dfb 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -670,7 +670,7 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc, goto err_already_mapped; } - area = get_vm_area(vma->vm_end - vma->vm_start, VM_IOREMAP); + area = get_vm_area(vma->vm_end - vma->vm_start, VM_ALLOC); if (area == NULL) { ret = -ENOMEM; failure_string = "get_vm_area"; -- 2.16.1