linux-kernel - Re: [PATCHSET v5 0/12] Add support for async buffered reads

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Message-ID: <20200605223635.6xesl7u4lxszvico@alap3.anarazel.de>
Date:   Fri, 5 Jun 2020 15:36:35 -0700
From:   Andres Freund <andres@...razel.de>
To:     Jens Axboe <axboe@...nel.dk>
Cc:     io-uring@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        akpm@...ux-foundation.org
Subject: Re: [PATCHSET v5 0/12] Add support for async buffered reads

Hi,

On 2020-06-05 15:30:44 -0700, Andres Freund wrote:
> On 2020-06-05 15:21:34 -0600, Jens Axboe wrote:
> > >> I can reproduce this, and I see what it is. I'll send out a patch soonish.
> > > 
> > > Thinko, can you try with this on top?
> > 
> > Sorry that was incomplete, please use this one!
> 
> That seems to fix it! Yay.
> 
> 
> Bulk buffered reads somehow don't quite seem to be performing that well
> though, looking into it. Could be on the pg side too.

While looking into that, I played with setting
/sys/<dev>/queue/read_ahead_kb to 0 and noticed that seems to result in
all/most IO done in workers. Is that to be expected?

Greetings,

Andres Freund