From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751216AbeAVPya (ORCPT ); Mon, 22 Jan 2018 10:54:30 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:34960 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751028AbeAVPy3 (ORCPT ); Mon, 22 Jan 2018 10:54:29 -0500 Date: Mon, 22 Jan 2018 16:54:28 +0100 From: Greg KH To: Ganesh Mahendran Cc: maco@android.com, tkjos@google.com, arve@android.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] android: binder: use VM_ALLOC to get vm area Message-ID: <20180122155428.GB7714@kroah.com> References: <1515552545-18311-1-git-send-email-opensource.ganesh@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1515552545-18311-1-git-send-email-opensource.ganesh@gmail.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 10, 2018 at 10:49:05AM +0800, Ganesh Mahendran wrote: > 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 > ---- > V3: update comments > V2: update comments > --- > drivers/android/binder_alloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Martijn and Todd, any objections to this patch? thanks, greg k-h