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Date:   Fri, 27 May 2022 12:36:35 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Ingo Molnar <mingo@kernel.org>
Cc:     "Jason A. Donenfeld" <Jason@zx2c4.com>,
        Samuel Neves <sneves@dei.uc.pt>, Jens Axboe <axboe@kernel.dk>,
        Matthew Wilcox <willy@infradead.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@lst.de>, linux-fsdevel@vger.kernel.org,
        x86@kernel.org
Subject: Re: [RFC] what to do with IOCB_DSYNC?
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On Fri, May 27, 2022 at 12:25:53PM +0200, Ingo Molnar wrote:
> Turns out Boris just sent a competing optimization to clear_user() 3 days ago:
> 
>   https://lore.kernel.org/r/YozQZMyQ0NDdD8cH@zn.tnic

Yes, and that one needs to be properly measured and verified it doesn't
impact any workload. I have been working on this for a while now so
let's all relax ourselves - it'll get fixed properly eventually.

What you could do in the meantime is, run it and see if your
microbenchmarks are happy with it.

Because clear_user() doesn't matter one whit in real workloads, as we
realized upthread.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette