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Date:   Sun, 19 Jan 2020 10:17:15 +0800
From:   Wei Yang <richardw.yang@linux.intel.com>
To:     Mike Kravetz <mike.kravetz@oracle.com>
Cc:     Wei Yang <richardw.yang@linux.intel.com>,
        Yang Shi <shy828301@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux MM <linux-mm@kvack.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm/migrate.c: also overwrite error when it is bigger
 than zero
Message-ID: <20200119021715.GB9745@richard>
Reply-To: Wei Yang <richardw.yang@linux.intel.com>
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On Fri, Jan 17, 2020 at 05:38:10PM -0800, Mike Kravetz wrote:
>On 1/17/20 3:48 PM, Wei Yang wrote:
>> This is another point I think current code is not working well. And actually,
>> the behavior is not well defined or our kernel is broken for a while.
>> 
>> When you look at the man page, it says:
>> 
>>     RETURN VALUE
>>            On success move_pages() returns zero.  On error, it returns -1, and sets errno to indicate the error
>> 
>
>Is this from your migrate_pages(2) man page?
>

It is from my move_pages(2) man page.

>The latest version of the migrate_pages(2) man page in the git repo has this
>for RETURN VALUE.
>
>RETURN VALUE
>       On  success  migrate_pages() returns the number of pages that could not
>       be moved (i.e., a return of zero means that all pages were successfully
>       moved).  On error, it returns -1, and sets errno to indicate the error.
>
>-- 
>Mike Kravetz

-- 
Wei Yang
Help you, Help me