Re: [RFC] /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_overcommit_hugepages

On Wed 05-01-11 11:42:01, CAI Qian wrote:

----- Original Message -----

quoted

On Wed 05-01-11 10:36:47, CAI Qian wrote:

quoted

From f90b54f9f5607128e375bd78d21e751c433b3cf6 Mon Sep 17 00:00:00
2001
From: CAI Qian <redacted>
Date: Wed, 5 Jan 2011 23:26:57 +0800
Subject: [PATCH] hugetlbfs: check invalid nr_hugepages and
nr_overcommit_hugepages

First, nr_*hugepages* in procfs and sysfs do not check for invalid
input like "". Second, when using oversize pages, nr_*hugepages* are
expected to be allocated during boot time. Therefore, return -EINVAL
for those cases.

I think that the two things should be split into two patches - one for
the proper input data handling and the other one for the size check.
Albeit, I am not sure about the size check because this is a thing
that is just a current implementation limitation and can be change later.

OK, will do two patches.

Then you can use the patch I sent earlier and make just a size check
patch on top of it, right?

quoted

quoted

Signed-off-by: CAI Qian <redacted>
---
 fs/sysfs/file.c | 2 ++
 mm/hugetlb.c | 18 ++++++++++++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index da3fefe..9f4ea67 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c

@@ -207,6 +207,8 @@ flush_write_buffer(struct dentry * dentry,

struct sysfs_buffer * buffer, size_t
 		return -ENODEV;

 	rc = ops->store(kobj, attr_sd->s_attr.attr, buffer->page, count);
+ if (!rc)
+ return -EINVAL;

This doesn't look correct, you would imbalance sysfs_{get,put}_active.

Right, I'll fix this up.

Thanks.

CAI Qian

-- 
Michal Hocko
L3 team 
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic

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