From: Andrew Morton <akpm@linux-foundation.org>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: LKML <linux-kernel@vger.kernel.org>, linux-mm <linux-mm@kvack.org>
Subject: Re: [PATCH] reduce stack usage of node_read_meminfo()
Date: Thu, 8 Jul 2010 13:58:05 -0700 [thread overview]
Message-ID: <20100708135805.b4411965.akpm@linux-foundation.org> (raw)
In-Reply-To: <20100708181629.CD3C.A69D9226@jp.fujitsu.com>
On Thu, 8 Jul 2010 18:20:14 +0900 (JST)
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote:
>
> Now, cmpilation node_read_meminfo() output following warning. Because
> it has very large sprintf() argument.
>
> drivers/base/node.c: In function 'node_read_meminfo':
> drivers/base/node.c:139: warning: the frame size of 848 bytes is
> larger than 512 bytes
hm, I'm surprised it's that much.
> --- a/drivers/base/node.c
> +++ b/drivers/base/node.c
> @@ -66,8 +66,7 @@ static ssize_t node_read_meminfo(struct sys_device * dev,
> struct sysinfo i;
>
> si_meminfo_node(&i, nid);
> -
> - n = sprintf(buf, "\n"
> + n = sprintf(buf,
> "Node %d MemTotal: %8lu kB\n"
> "Node %d MemFree: %8lu kB\n"
> "Node %d MemUsed: %8lu kB\n"
> @@ -78,13 +77,33 @@ static ssize_t node_read_meminfo(struct sys_device * dev,
> "Node %d Active(file): %8lu kB\n"
> "Node %d Inactive(file): %8lu kB\n"
> "Node %d Unevictable: %8lu kB\n"
> - "Node %d Mlocked: %8lu kB\n"
> + "Node %d Mlocked: %8lu kB\n",
> + nid, K(i.totalram),
> + nid, K(i.freeram),
> + nid, K(i.totalram - i.freeram),
> + nid, K(node_page_state(nid, NR_ACTIVE_ANON) +
> + node_page_state(nid, NR_ACTIVE_FILE)),
Why the heck did we decide to print the same node-id 10000 times?
> + n += sprintf(buf,
You just got caught sending untested patches.
--- a/drivers/base/node.c~drivers-base-nodec-reduce-stack-usage-of-node_read_meminfo-fix
+++ a/drivers/base/node.c
@@ -93,7 +93,7 @@ static ssize_t node_read_meminfo(struct
nid, K(node_page_state(nid, NR_MLOCK)));
#ifdef CONFIG_HIGHMEM
- n += sprintf(buf,
+ n += sprintf(buf + n,
"Node %d HighTotal: %8lu kB\n"
"Node %d HighFree: %8lu kB\n"
"Node %d LowTotal: %8lu kB\n"
@@ -103,7 +103,7 @@ static ssize_t node_read_meminfo(struct
nid, K(i.totalram - i.totalhigh),
nid, K(i.freeram - i.freehigh));
#endif
- n += sprintf(buf,
+ n += sprintf(buf + n,
"Node %d Dirty: %8lu kB\n"
"Node %d Writeback: %8lu kB\n"
"Node %d FilePages: %8lu kB\n"
_
Please, run the code and check that we didn't muck up the output.
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next prev parent reply other threads:[~2010-07-08 20:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-08 9:20 KOSAKI Motohiro
2010-07-08 10:41 ` KOSAKI Motohiro
2010-07-08 20:59 ` Andrew Morton
2010-07-08 20:58 ` Andrew Morton [this message]
2010-07-09 0:14 ` KOSAKI Motohiro
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