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Subject: Re: [iov_iter] 9bd0e337c6: will-it-scale.per_process_ops -4.8% regression
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Date:   Fri, 04 Dec 2020 11:50:36 +0000
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Linus Torvalds <torvalds@linux-foundation.org> wrote:

> > FYI, we noticed a -4.8% regression of will-it-scale.per_process_ops du=
e to commit:
> =

> Ok, I guess that's bigger than expected, =


Note that it appears to be testing just the first patch and not the whole
series:

| commit: 9bd0e337c633aed3e8ec3c7397b7ae0b8436f163 ("[PATCH 01/29] iov_ite=
r: Switch to using a table of operations")

that just adds an indirection table without taking away any of the conditi=
onal
branching.  It seems quite likely, though, that even if you add all the ot=
her
patches, you won't get back enough to make it worth it.

David