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From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Christophe Leroy <christophe.leroy@csgroup.eu>
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Subject: Re: remove the last set_fs() in common code, and remove it for x86
 and powerpc v2
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On Tue, Sep 01, 2020 at 07:13:00PM +0200, Christophe Leroy wrote:

>     10.92%  dd       [kernel.kallsyms]  [k] iov_iter_zero

Interesting...  Could you get an instruction-level profile inside iov_iter_zero(),
along with the disassembly of that sucker?