From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750984AbdEaEj0 (ORCPT ); Wed, 31 May 2017 00:39:26 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:6838 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750883AbdEaEjZ (ORCPT ); Wed, 31 May 2017 00:39:25 -0400 Subject: Re: [RFC PATCH] vmalloc: show more detail info in vmallocinfo for clarify To: Tim Chen , , , , , , , , References: <1495262861-37649-1-git-send-email-xieyisheng1@huawei.com> <857f6900-8a28-6ac6-64ac-d4867ef01ee5@linux.intel.com> CC: , , From: Yisheng Xie Message-ID: <25eb2159-5398-856d-abcf-457cac84771b@huawei.com> Date: Wed, 31 May 2017 12:35:24 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <857f6900-8a28-6ac6-64ac-d4867ef01ee5@linux.intel.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.40] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A010205.592E4829.0014,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 7748b3ef7c208f206e2880df97d9d836 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tim, Thanks for comment! On 2017/5/31 8:56, Tim Chen wrote: > On 05/19/2017 11:47 PM, Yisheng Xie wrote: >> 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 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 freeing vm_area >> 0xece7e000-0xece83000 20480 vm_map_ram >> 0xf0099000-0xf00aa000 69632 vm_map_ram >> 0xf1000000-0xf5001000 67112960 devm_ioremap+0x38/0x7c phys=40000000 ioremap >> after apply this patch. >> >> Signed-off-by: Yisheng Xie >> --- >> mm/vmalloc.c | 10 +++++++++- >> 1 file changed, 9 insertions(+), 1 deletion(-) >> >> diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> index b52aeed..dbb24fc 100644 >> --- a/mm/vmalloc.c >> +++ b/mm/vmalloc.c >> @@ -314,6 +314,7 @@ unsigned long vmalloc_to_pfn(const void *vmalloc_addr) >> >> /*** Global kva allocator ***/ >> >> +#define VM_LAZY_FREE 0x02 >> #define VM_VM_AREA 0x04 >> >> static DEFINE_SPINLOCK(vmap_area_lock); >> @@ -1486,6 +1487,7 @@ struct vm_struct *remove_vm_area(const void *addr) >> spin_lock(&vmap_area_lock); >> va->vm = NULL; >> va->flags &= ~VM_VM_AREA; >> + va->flags |= VM_LAZY_FREE; >> spin_unlock(&vmap_area_lock); >> >> vmap_debug_free_range(va->va_start, va->va_end); >> @@ -2684,8 +2686,14 @@ static int s_show(struct seq_file *m, void *p) >> * s_show can encounter race with remove_vm_area, !VM_VM_AREA on >> * behalf of vmap area is being tear down or vm_map_ram allocation. >> */ >> - if (!(va->flags & VM_VM_AREA)) >> + if (!(va->flags & VM_VM_AREA)) { >> + seq_printf(m, "0x%pK-0x%pK %7ld %s\n", >> + (void *)va->va_start, (void *)va->va_end, >> + va->va_end - va->va_start, >> + va->flags & VM_LAZY_FREE ? "freeing vm_area" : "vm_map_ram"); > > Will be clearer to say "unpurged vm_area" instead of "freeing vm_area". Yes, I will change it in next version. Thanks Yisheng Xie > > Thanks. > > Tim > > . >