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From: Xiaoguang Wang <[email protected]>
To: io-uring <[email protected]>
Cc: "[email protected]" <[email protected]>,
	joseph qi <[email protected]>
Subject: Does need memory barrier to synchronize req->result with req->iopoll_completed
Date: Sun, 14 Jun 2020 22:10:39 +0800	[thread overview]
Message-ID: <[email protected]> (raw)

hi,

I have taken some further thoughts about previous IPOLL race fix patch,
if io_complete_rw_iopoll() is called in interrupt context, "req->result = res"
and "WRITE_ONCE(req->iopoll_completed, 1);" are independent store operations.
So in io_do_iopoll(), if iopoll_completed is ture, can we make sure that
req->result has already been perceived by the cpu executing io_do_iopoll()?

Regards,
Xiaoguang Wang

             reply	other threads:[~2020-06-14 14:10 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-14 14:10 Xiaoguang Wang [this message]
2020-06-14 15:36 ` Does need memory barrier to synchronize req->result with req->iopoll_completed Jens Axboe
2020-06-15  2:10   ` Xiaoguang Wang
2020-06-16 17:31   ` Bijan Mottahedeh
2020-06-16 19:35     ` Jens Axboe

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