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From: Yang Shi <yang.shi@linux.alibaba.com>
To: "linux-mm@kvack.org" <linux-mm@kvack.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: [Question] Why PageReadahead is not migrated by migration code?
Date: Thu, 13 Feb 2020 09:06:58 -0800	[thread overview]
Message-ID: <7691ab12-2e84-2531-f27d-2fae9045576d@linux.alibaba.com> (raw)

Hi folks,


Recently we saw some PageReadahead related bugs, so I did a quick check 
about the use of PageReadahead. I just found the state is *not* migrated 
by migrate_page_states().


Since migrate_page() won't migrate writeback page, so if PageReadahead 
is set it should just mean PG_readahead rather than PG_reclaim. So, I 
didn't think of why it is not migrated.


I dig into the history a little bit, but the change in migration code is 
too overwhelming. But, it looks PG_readahead was added after migration 
was introduced. Is it just a simple omission?


Thanks,

Yang



             reply	other threads:[~2020-02-13 17:11 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-13 17:06 Yang Shi [this message]
2020-02-13 17:33 ` Matthew Wilcox
2020-02-13 18:04   ` Yang Shi

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