Re: [PATCHv2 1/8] khugepaged: Add self test

From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Zi Yan <ziy@nvidia.com>
Cc: akpm@linux-foundation.org, Andrea Arcangeli <aarcange@redhat.com>,
	Yang Shi <yang.shi@linux.alibaba.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCHv2 1/8] khugepaged: Add self test
Date: Mon, 6 Apr 2020 18:20:35 +0300	[thread overview]
Message-ID: <20200406152035.ga7hk6jfaqzvlete@box> (raw)
In-Reply-To: <D55D6A3A-47A1-41F5-B939-36EEA740CF72@nvidia.com>

On Mon, Apr 06, 2020 at 10:59:52AM -0400, Zi Yan wrote:
> I ran this test with all patches from this series applied to Linus’s
> tree, but still see several failures. Is it expected?

[Thanks for catching all my typos]

No. It works fine for me.
Well, occasionally, it fails to swap out a page, but nothing like you have
here.

Could you try to trace it? I used script like below after mounting
tracefs. You may want to comment out all tests but a failing one.

#!/bin/sh -efu

echo > /sys/kernel/tracing/trace
echo 1 > /sys/kernel/tracing/events/huge_memory/enable

while ./khugepaged; do
	echo > /sys/kernel/tracing/trace
done

cat /sys/kernel/tracing/trace

-- 
 Kirill A. Shutemov