Hi Rientjes Thanks a lot for your info, yes, you are right, I just re-send the patch, could you please review?
Br Xiaobing -----Original Message----- From: David Rientjes [mailto:[email protected]] Sent: Wednesday, January 30, 2013 5:49 AM To: Tu, Xiaobing Cc: [email protected]; Tang, Guifang; Chen, LinX Z; Andrew Morton Subject: Re: Avoid high order memory allocating with kmalloc, when read large seq file On Tue, 29 Jan 2013, xtu4 wrote: > 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] [<c185c836>] ? printk+0x1d/0x1f [ 4356.532467] > [<c12cde1f>] warn_alloc_failed+0xbf/0xf0 [ 4356.532491] [<c12d0aba>] > __alloc_pages_nodemask+0x4ba/0x6a0 > [ 4356.532521] [<c12d0d1c>] __get_free_pages+0x1c/0x30 [ 4356.532541] > [<c12f51e1>] kmalloc_order_trace+0x21/0xd0 [ 4356.532561] > [<c131d0f7>] ? seq_read+0x137/0x390 [ 4356.532579] [<c12f549a>] > __kmalloc+0x20a/0x230 [ 4356.532596] [<c131d0f7>] ? > seq_read+0x137/0x390 [ 4356.532616] [<c12d343c>] ? put_page+0x2c/0x40 > [ 4356.532634] [<c12f4a7d>] ? kfree+0xcd/0x160 [ 4356.532655] > [<c18656cd>] ? mutex_unlock+0xd/0x10 [ 4356.532675] [<c131d109>] > seq_read+0x149/0x390 [ 4356.532697] [<c130062c>] vfs_read+0x8c/0x160 > [ 4356.532716] [<c131cfc0>] ? seq_lseek+0x180/0x180 [ 4356.532735] > [<c130073d>] sys_read+0x3d/0x70 [ 4356.532755] [<c1866e91>] > syscall_call+0x7/0xb [ 4356.532777] [<c1860000>] ? > log_dir_items+0x33d/0x40c > Signed-off-by: xiaobing tu <[email protected]> > Signed-off-by: linX z chen <[email protected]> > Signed-off-by: guifang tang <[email protected]> > 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); I thought m->size was already shifted. Your patch is severely mangled, please check out Documentation/SubmittingPatches and Documentation/email-clients.txt. > + > + > 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; > } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
