From mboxrd@z Thu Jan  1 00:00:00 1970
From: Richard Cochran <richardcochran@gmail.com>
Subject: Re: [PATCH net-next V2 3/4] net/mlx5e: Add HW timestamping (TS)
 support
Date: Mon, 21 Dec 2015 19:35:08 +0100
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Cc: Saeed Mahameed <saeedm@mellanox.com>,
	"David S. Miller" <davem@davemloft.net>, netdev@vger.kernel.org,
	Or Gerlitz <ogerlitz@mellanox.com>,
	Eran Ben Elisha <eranbe@mellanox.com>,
	Tal Alon <talal@mellanox.com>,
	Majd Dibbiny <majd@mellanox.com>,
	Achiad Shochat <achiad@mellanox.com>
To: Saeed Mahameed <saeedm@dev.mellanox.co.il>
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On Mon, Dec 21, 2015 at 04:35:23PM +0200, Saeed Mahameed wrote:
> think of a case where:
> CPU1: is just about to call
> "schedule_delayed_work(&tstamp->overflow_work,
> tstamp->overflow_period);"
> CPU2: cancel_delayed_work
> 
> In this case cancel_dalyed_work_sync (CPU2) will wait for CPU1 to
> complete but CPU1 will re-arm the work, and we will
> be left with tstamp->overflow_work running forever.

This is my understanding:  Once the work becomes re-queued, it will be
canceled before running again.

Thanks,
Richard