From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754047Ab3AaGL3 (ORCPT ); Thu, 31 Jan 2013 01:11:29 -0500 Received: from mga01.intel.com ([192.55.52.88]:1101 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750941Ab3AaGL0 (ORCPT ); Thu, 31 Jan 2013 01:11:26 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,574,1355126400"; d="scan'208";a="280682851" Message-ID: <510A0B14.70800@intel.com> Date: Thu, 31 Jan 2013 14:11:32 +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: resend----[PATCH] Avoid high order memory allocating with kmalloc, when read large seq file References: <510768B6.3070000@intel.com> In-Reply-To: <510768B6.3070000@intel.com> 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 [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 the m->size is very huge <3>[ 1185.457656, 1] xiaobing >> seq_read: m->size 8192 <3>[ 1185.463462, 1] xiaobing >> seq_read: m->size 16384 <3>[ 1185.470472, 1] xiaobing >> seq_read: m->size 32768 <3>[ 1185.481201, 0] xiaobing >> seq_read: m->size 8192 <3>[ 1185.488071, 0] xiaobing >> seq_read: m->size 16384 <3>[ 1185.495892, 0] xiaobing >> seq_read: m->size 32768 <3>[ 1185.504841, 0] xiaobing >> seq_read: m->size 65536 <3>[ 1185.517180, 0] xiaobing >> seq_read: m->size 131072 <3>[ 1185.536286, 0] xiaobing >> seq_read: m->size 262144 some times even more then 262144 byte Signed-off-by: xiaobing tu Change-Id: I892c97d02cf25e59b23c9bc68dff754ea01c1d56 --- fs/seq_file.c | 22 +++++++++++++++++----- 1 files changed, 17 insertions(+), 5 deletions(-) diff --git a/fs/seq_file.c b/fs/seq_file.c index dba43c3..19df826 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -12,7 +12,7 @@ #include #include - +#include /** * seq_open - initialize sequential file * @file: file we initialize @@ -116,7 +116,13 @@ static int traverse(struct seq_file *m, loff_t offset) Eoverflow: m->op->stop(m, p); kfree(m->buf); - m->buf = kmalloc(m->size <<= 1, GFP_KERNEL); + + is_vmalloc_addr(m->buf) ? vfree(m->buf) : kfree(m->buf); + m->size <<= 1; + if (m->size <= (2 * PAGE_SIZE)) + m->buf = kmalloc(m->size, GFP_KERNEL); + else + m->buf = vmalloc(m->size); return !m->buf ? -ENOMEM : -EAGAIN; } @@ -209,8 +215,14 @@ 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); + is_vmalloc_addr(m->buf) ? vfree(m->buf) : kfree(m->buf); + m->size <<= 1; + if (m->size > 2 * PAGE_SIZE) + m->buf = vmalloc(m->size); + else + m->buf = kmalloc(m->size, GFP_KERNEL); + + if (!m->buf) goto Enomem; m->count = 0; @@ -325,7 +337,7 @@ EXPORT_SYMBOL(seq_lseek); int seq_release(struct inode *inode, struct file *file) { struct seq_file *m = file->private_data; - kfree(m->buf); + is_vmalloc_addr(m->buf) ? vfree(m->buf) : kfree(m->buf); kfree(m); return 0; } -- 1.7.6