linux-kernel - Re: [PATCH 0/4] De-couple sysfs memory directories from memory sections

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Date:	Mon, 10 Jan 2011 13:11:22 -0600
From:	Robin Holt <holt@....com>
To:	Nathan Fontenot <nfont@...tin.ibm.com>
Cc:	Greg KH <greg@...ah.com>, linux-kernel@...r.kernel.org,
	linuxppc-dev@...ts.ozlabs.org, linux-mm@...ck.org,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Robin Holt <holt@....com>
Subject: Re: [PATCH 0/4] De-couple sysfs memory directories from memory
 sections

> >> The root of this issue is in sysfs directory creation. Every time
> >> a directory is created a string compare is done against all sibling
> >> directories 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.
> > 
> > Are you sure this is still an issue?  I thought we solved this last
> > kernel or so with a simple patch?
> 
> I'll go back and look at this again.

What I recall fixing is the symbolic linking from the node* to the
memory section.  In that case, we cached the most recent mem section
and since they always were added sequentially, the cache saved a rescan.

Of course, I could be remembering something completely unrelated.

Robin
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