From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754071Ab3A2GOE (ORCPT ); Tue, 29 Jan 2013 01:14:04 -0500 Received: from mga02.intel.com ([134.134.136.20]:29170 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753574Ab3A2GOD (ORCPT ); Tue, 29 Jan 2013 01:14:03 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,557,1355126400"; d="scan'208";a="253974425" Message-ID: <510768B6.3070000@intel.com> Date: Tue, 29 Jan 2013 14:14:14 +0800 From: xtu4 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, guifang.tang@intel.com, linX.z.chen@intel.com, akpm@linux-foundation.org Subject: Avoid high order memory allocating with kmalloc, when read large seq file Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Subject: [PATCH] [SEQ_FILE] Avoid high order memory allocating with kmalloc when read large seq file currently, when dumpstate access /proc/xxx/binder , this binder include lots of info, it will use seq_read in kernel, in this function, it will trigger high order memory alloc, when read binder info or other large file, this will cause memory presure when system don't have contious high order memory, it will lead to high kswap workload to reclaim the page. so change kmalloc to vmalloc, it can avoid contiously high order memory allocating. [ 4356.532357] dumpstate: page allocation failure: order:4, mode:0x40d0 [ 4356.532400] Pid: 18256, comm: dumpstate Tainted: G C 3.0.34-141128-g4be7088 #1 [ 4356.532416] Call Trace: [ 4356.532443] [] ? printk+0x1d/0x1f [ 4356.532467] [] warn_alloc_failed+0xbf/0xf0 [ 4356.532491] [] __alloc_pages_nodemask+0x4ba/0x6a0 [ 4356.532521] [] __get_free_pages+0x1c/0x30 [ 4356.532541] [] kmalloc_order_trace+0x21/0xd0 [ 4356.532561] [] ? seq_read+0x137/0x390 [ 4356.532579] [] __kmalloc+0x20a/0x230 [ 4356.532596] [] ? seq_read+0x137/0x390 [ 4356.532616] [] ? put_page+0x2c/0x40 [ 4356.532634] [] ? kfree+0xcd/0x160 [ 4356.532655] [] ? mutex_unlock+0xd/0x10 [ 4356.532675] [] seq_read+0x149/0x390 [ 4356.532697] [] vfs_read+0x8c/0x160 [ 4356.532716] [] ? seq_lseek+0x180/0x180 [ 4356.532735] [] sys_read+0x3d/0x70 [ 4356.532755] [] syscall_call+0x7/0xb [ 4356.532777] [] ? log_dir_items+0x33d/0x40c Signed-off-by: xiaobing tu Signed-off-by: linX z chen Signed-off-by: guifang tang Change-Id: I892c97d02cf25e59b23c9bc68dff754ea01c1d56 --- fs/seq_file.c | 18 +++++++++++++++--- 1 files changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/seq_file.c b/fs/seq_file.c index dba43c3..20b8e36 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -209,8 +209,17 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) if (m->count < m->size) goto Fill; m->op->stop(m, p); - kfree(m->buf); - m->buf = kmalloc(m->size <<= 1, GFP_KERNEL); + if (m->size > 2 * PAGE_SIZE) { + vfree(m->buf); + } else + kfree(m->buf); + m->size <<= 1; + if (m->size > 2 * PAGE_SIZE) { + m->buf = vmalloc(m->size); + } else + m->buf = kmalloc(m->size <<= 1, GFP_KERNEL); + + if (!m->buf) goto Enomem; m->count = 0; @@ -325,7 +334,10 @@ EXPORT_SYMBOL(seq_lseek); int seq_release(struct inode *inode, struct file *file) { struct seq_file *m = file->private_data; - kfree(m->buf); + if (m->size > 2 * PAGE_SIZE) { + vfree(m->buf); + } else + kfree(m->buf); kfree(m); return 0; } -- 1.7.6