linux-kernel - Re: [PATCH v2 0/3] symlink length caching

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Message-ID: <CAGudoHFnwtetYnypHWhS8sODnmcjnRy8VkR-YbV0MP9St3g89g@mail.gmail.com>
Date: Tue, 19 Nov 2024 19:07:33 +0100
From: Mateusz Guzik <mjguzik@...il.com>
To: "Theodore Ts'o" <tytso@....edu>
Cc: brauner@...nel.org, viro@...iv.linux.org.uk, jack@...e.cz, 
	linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org, hughd@...gle.com, 
	linux-ext4@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH v2 0/3] symlink length caching

On Tue, Nov 19, 2024 at 6:53 PM Theodore Ts'o <tytso@....edu> wrote:
>
> On Tue, Nov 19, 2024 at 10:45:52AM +0100, Mateusz Guzik wrote:
> >
> > On my v1 Jan remarked 1.5% is not a particularly high win questioning
> > whether doing this makes sense. I noted the value is only this small
> > because of other slowdowns.
>
> Do you have a workload in mind which calls readlink() at sufficiently
> high numbers such that this would be noticeable in
> non-micro-benchmarks?  What motiviated you to do this work?
>

I'm just messing about here. Given the triviality of the patch I'm not
sure where the objection is coming from. I can point a finger at
changes made by other people for supposed perf gains which are
virtually guaranteed to be invisible in isolation, just like this one.

Anyhow, I landed here from strlen -- the sucker is operating one byte
at a time which I was looking to sort out, but then I noticed that one
of the more commonly executing consumers does not even need to call
it.
-- 
Mateusz Guzik <mjguzik gmail.com>