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Date: Thu, 4 Jan 2018 23:11:37 +0000
From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>,
        Pavel Machek <pavel@ucw.cz>,
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        Elena Reshetova <elena.reshetova@intel.com>,
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        Dan Carpenter <dan.carpenter@oracle.com>
Subject: Re: [RFC PATCH] asm/generic: introduce if_nospec and nospec_barrier
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> It's also possible that x86 'lfence' really is so fast that it doesn't
> make sense to try to do this.

If you've got a lot going on it's not 1 cycle.

Alan