Message-ID: <2899c7841c8afc23b329230bd940692ffd586f63.camel@gmx.de>
Subject: Re: [PATCH 1/1] mm: vmscan: Reduce throttling due to a failure to
 make progress
From:   Mike Galbraith <efault@gmx.de>
To:     Mel Gorman <mgorman@techsingularity.net>
Cc:     Alexey Avramov <hakavlad@inbox.lv>,
        Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@suse.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Rik van Riel <riel@surriel.com>,
        Darrick Wong <djwong@kernel.org>, regressions@lists.linux.dev,
        Linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux-MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
Date:   Wed, 01 Dec 2021 14:52:01 +0100
In-Reply-To: <20211201130155.GT3366@techsingularity.net>
References: <20211125151853.8540-1-mgorman@techsingularity.net>
         <20211127011246.7a8ac7b8@mail.inbox.lv>
         <20211129150117.GO3366@techsingularity.net>
         <20211201010348.31e99637@mail.inbox.lv>
         <20211130172754.GS3366@techsingularity.net>
         <c2aee7e6b9096556aab9b47156e91082c9345a90.camel@gmx.de>
         <20211201130155.GT3366@techsingularity.net>
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On Wed, 2021-12-01 at 13:01 +0000, Mel Gorman wrote:
> On Tue, Nov 30, 2021 at 06:59:58PM +0100, Mike Galbraith wrote:
> > On Tue, 2021-11-30 at 17:27 +0000, Mel Gorman wrote:
> > >
> > > Obviously a fairly different experience and most likely due to
> > > the
> > > underlying storage.
> >
> > I bet a virtual nickle this is the sore spot.
> >
>
> You win a virtual nickle!

I'm rich I'm rich... oh dang, virtual.

I went back to 5.15, and confirmed that wait_iff_congested() did not
ever sleep with the try to eat /dev/zero load.  Nor did it with insane
overcommit swap storm from hell with as much IO going on as my little
box is capable of generating, making the surrounding congestion bits
look.. down right expendable.

	-Mike