Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757611Ab0GIAOg (ORCPT ); Thu, 8 Jul 2010 20:14:36 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:33832 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755311Ab0GIAOf (ORCPT ); Thu, 8 Jul 2010 20:14:35 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Andrew Morton Subject: Re: [PATCH] reduce stack usage of node_read_meminfo() Cc: kosaki.motohiro@jp.fujitsu.com, LKML , linux-mm In-Reply-To: <20100708135805.b4411965.akpm@linux-foundation.org> References: <20100708181629.CD3C.A69D9226@jp.fujitsu.com> <20100708135805.b4411965.akpm@linux-foundation.org> Message-Id: <20100709091138.CD57.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Fri, 9 Jul 2010 09:14:31 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2829 Lines: 85 > On Thu, 8 Jul 2010 18:20:14 +0900 (JST) > KOSAKI Motohiro 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. me too. > > > --- 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? dunno. but I don't want to make behavior change for only stack reducing. > > > + 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. 100% my fault. I ran it, but I forgot to merge two patches ;) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/