From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751941AbdHALCI (ORCPT ); Tue, 1 Aug 2017 07:02:08 -0400 Received: from ozlabs.org ([103.22.144.67]:43681 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751339AbdHALAW (ORCPT ); Tue, 1 Aug 2017 07:00:22 -0400 From: Michael Ellerman To: Yisheng Xie , akpm@linux-foundation.org Cc: mhocko@suse.com, zijun_hu@htc.com, mingo@kernel.org, thgarnie@google.com, kirill.shutemov@linux.intel.com, aryabinin@virtuozzo.com, chris@chris-wilson.co.uk, tim.c.chen@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, guohanjun@huawei.com Subject: Re: [PATCH v2] vmalloc: show more detail info in vmallocinfo for clarify In-Reply-To: <1496649682-20710-1-git-send-email-xieyisheng1@huawei.com> References: <1496649682-20710-1-git-send-email-xieyisheng1@huawei.com> User-Agent: Notmuch/0.21 (https://notmuchmail.org) Date: Tue, 01 Aug 2017 21:00:20 +1000 Message-ID: <87o9rzsgcb.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Yisheng Xie writes: > When ioremap a 67112960 bytes vm_area with the vmallocinfo: > [..] > 0xec79b000-0xec7fa000 389120 ftl_add_mtd+0x4d0/0x754 pages=94 vmalloc > 0xec800000-0xecbe1000 4067328 kbox_proc_mem_write+0x104/0x1c4 phys=8b520000 ioremap > > we get the result: > 0xf1000000-0xf5001000 67112960 devm_ioremap+0x38/0x7c phys=40000000 ioremap > > For the align for ioremap must be less than '1 << IOREMAP_MAX_ORDER': > if (flags & VM_IOREMAP) > align = 1ul << clamp_t(int, get_count_order_long(size), > PAGE_SHIFT, IOREMAP_MAX_ORDER); > > So it makes idiot like me a litter puzzle why jump the vm_area from > 0xec800000-0xecbe1000 to 0xf1000000-0xf5001000, and leave > 0xed000000-0xf1000000 as a big hole. > > This is to show all of vm_area, including which is freeing but still in > vmap_area_list, to make it more clear about why we will get > 0xf1000000-0xf5001000 int the above case. And we will get the > vmallocinfo like: > [..] > 0xec79b000-0xec7fa000 389120 ftl_add_mtd+0x4d0/0x754 pages=94 vmalloc > 0xec800000-0xecbe1000 4067328 kbox_proc_mem_write+0x104/0x1c4 phys=8b520000 ioremap > [..] > 0xece7c000-0xece7e000 8192 unpurged vm_area > 0xece7e000-0xece83000 20480 vm_map_ram > 0xf0099000-0xf00aa000 69632 vm_map_ram My vmallocinfo is full of these unpurged areas, should I be worried? # grep -c "unpurged" /proc/vmallocinfo 311 cheers