From: Nathan Fontenot <nfont@austin.ibm.com>
To: Greg KH <greg@kroah.com>
Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Robin Holt <holt@sgi.com>
Subject: Re: [PATCH 0/4] De-couple sysfs memory directories from memory sections
Date: Thu, 20 Jan 2011 10:51:44 -0600 [thread overview]
Message-ID: <4D386820.5080902@austin.ibm.com> (raw)
In-Reply-To: <20110120164555.GA30922@kroah.com>
On 01/20/2011 10:45 AM, Greg KH wrote:
> On Thu, Jan 20, 2011 at 10:36:40AM -0600, Nathan Fontenot wrote:
>> The root of this issue is in sysfs directory creation. Every time
>> a directory is created a string compare is done against sibling
>> directories ( see sysfs_find_dirent() ) to ensure we do not create
>> duplicates. The list of directory nodes in sysfs is kept as an
>> unsorted list which results in this being an exponentially longer
>> operation as the number of directories are created.
>
> Again, are you sure about this? I thought we resolved this issue in the
> past, but you were going to check it. Did you?
>
Yes, the string compare is still present in the sysfs code. There was
discussion around this sometime last year when I sent a patch out that
stored the directory entries in something other than a linked list.
That patch was rejected but it was agreed that something should be done.
-Nathan
WARNING: multiple messages have this Message-ID (diff)
From: Nathan Fontenot <nfont@austin.ibm.com>
To: Greg KH <greg@kroah.com>
Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Robin Holt <holt@sgi.com>
Subject: Re: [PATCH 0/4] De-couple sysfs memory directories from memory sections
Date: Thu, 20 Jan 2011 10:51:44 -0600 [thread overview]
Message-ID: <4D386820.5080902@austin.ibm.com> (raw)
In-Reply-To: <20110120164555.GA30922@kroah.com>
On 01/20/2011 10:45 AM, Greg KH wrote:
> On Thu, Jan 20, 2011 at 10:36:40AM -0600, Nathan Fontenot wrote:
>> The root of this issue is in sysfs directory creation. Every time
>> a directory is created a string compare is done against sibling
>> directories ( see sysfs_find_dirent() ) to ensure we do not create
>> duplicates. The list of directory nodes in sysfs is kept as an
>> unsorted list which results in this being an exponentially longer
>> operation as the number of directories are created.
>
> Again, are you sure about this? I thought we resolved this issue in the
> past, but you were going to check it. Did you?
>
Yes, the string compare is still present in the sysfs code. There was
discussion around this sometime last year when I sent a patch out that
stored the directory entries in something other than a linked list.
That patch was rejected but it was agreed that something should be done.
-Nathan
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next prev parent reply other threads:[~2011-01-20 16:51 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-20 16:36 [PATCH 0/4] De-couple sysfs memory directories from memory sections Nathan Fontenot
2011-01-20 16:36 ` Nathan Fontenot
2011-01-20 16:43 ` [PATCH 1/4] Allow memory blocks to span multiple " Nathan Fontenot
2011-01-20 16:43 ` Nathan Fontenot
2011-01-20 16:44 ` [PATCH 2/4] Update phys_index to [start|end]_section_nr Nathan Fontenot
2011-01-20 16:44 ` Nathan Fontenot
2011-01-20 16:45 ` [PATCH 3/4]Define memory_block_size_bytes for powerpc/pseries Nathan Fontenot
2011-01-20 16:45 ` Nathan Fontenot
2011-02-06 23:39 ` Benjamin Herrenschmidt
2011-02-06 23:39 ` Benjamin Herrenschmidt
2011-02-06 23:39 ` Benjamin Herrenschmidt
2011-02-07 1:42 ` Greg KH
2011-02-07 1:42 ` Greg KH
2011-02-07 1:42 ` Greg KH
2011-01-20 16:45 ` [PATCH 0/4] De-couple sysfs memory directories from memory sections Greg KH
2011-01-20 16:45 ` Greg KH
2011-01-20 16:51 ` Nathan Fontenot [this message]
2011-01-20 16:51 ` Nathan Fontenot
2011-01-20 17:25 ` Greg KH
2011-01-20 17:25 ` Greg KH
2011-01-20 17:09 ` Dave Hansen
2011-01-20 17:09 ` Dave Hansen
2011-01-20 17:09 ` Dave Hansen
2011-01-20 16:46 ` [PATCH 4/4] Define memory_block_size_bytes for x86_64 with CONFIG_X86_UV Nathan Fontenot
2011-01-20 16:46 ` Nathan Fontenot
-- strict thread matches above, loose matches on Subject: below --
2011-01-10 18:08 [PATCH 0/4] De-couple sysfs memory directories from memory sections Nathan Fontenot
2011-01-10 18:08 ` Nathan Fontenot
2011-01-10 18:08 ` Nathan Fontenot
2011-01-10 18:44 ` Greg KH
2011-01-10 18:44 ` Greg KH
2011-01-10 18:44 ` Greg KH
2011-01-10 18:47 ` Nathan Fontenot
2011-01-10 18:47 ` Nathan Fontenot
2011-01-10 18:47 ` Nathan Fontenot
2011-01-10 19:11 ` Robin Holt
2011-01-10 19:11 ` Robin Holt
2011-01-10 19:11 ` Robin Holt
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