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Date:   Tue, 24 Aug 2021 20:29:08 -0400
From:   Dave Jones <davej@codemonkey.org.uk>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: 5.14-rc breaks iotop swap io monitoring.
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On Tue, Aug 24, 2021 at 04:26:59PM -0700, Linus Torvalds wrote:
 > >  > What happens if you boot with the 'delayacct' kernel parameter.
 > >  >
 > > Yeah that boot option does make iotop work again.
 > 
 > Ok, so it's that delay allocation thing is it.
 > 
 > I'm inclined to let it be and see if somebody else notices, and how
 > big of a deal it is.
 >
 > The 'delayacct' kernel command line is an acceptable workaround if
 > this is something only a few people will even notice or care about.
 > 
 > I wonder how much people care about some statistics and iotop these days.
 > 
 > I also assume the swap stats still show up in "vmstat" etc, and that
 > it's just that iotop ended up using fancier interfaces?

afaict, vmstat is fine (though none of my machines are using swap, so
they're just reporting 0)

	Dave