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Date: Mon, 5 Sep 2011 23:20:09 +0400
From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        "Kirill A. Shutemov" <kirill@shutemov.name>, containers@lists.osdl.org,
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        Daniel Lezcano <dlezcano@fr.ibm.com>,
        Glauber Costa <glommer@parallels.com>,
        James Bottomley <jbottomley@parallels.com>, Tejun Heo <tj@kernel.org>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        Al Viro <viro@ZenIV.linux.org.uk>,
        Pavel Emelyanov <xemul@parallels.com>
Subject: Re: [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/
 directory v6
Message-ID: <20110905192009.GJ761@sun>
References: <20110831075814.003575573@openvz.org>
 <20110831080229.100652529@openvz.org>
 <20110831090612.GA3253@albatros>
 <20110831112642.GI25465@sun>
 <20110831140416.GA17626@shutemov.name>
 <20110831142622.GB30615@sun>
 <20110831151023.5b7e12da.akpm@linux-foundation.org>
 <20110901080508.GF30615@sun>
 <20110902163711.GA3124@albatros>
 <20110905185358.GA2103@albatros>
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On Mon, Sep 05, 2011 at 10:53:58PM +0400, Vasiliy Kulikov wrote:
...
>  
> +static int pid_no_revalidate(struct dentry *dentry, struct nameidata *nd)
> +{
> +	if (nd && nd->flags & LOOKUP_RCU)
> +		return -ECHILD;
> +
> +	d_drop(dentry);
> +	return 0;
> +}
> +

Thanks Vasiliy! So every lookup will cause dcache to drop previous cached
entry and alloc and hash new one instead, pretty dramatic, espec in case
of huge number of files mapped ;) Still since it's not time critical operation
(at least for now) I tend to agree.

	Cyrill