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From: Richard Cochran <richardcochran@gmail.com>
To: Hadar Hen Zion <hadarh@mellanox.com>
Cc: Shawn Bohrer <shawn.bohrer@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Or Gerlitz <ogerlitz@mellanox.com>,
	Amir Vadai <amirv@mellanox.com>,
	netdev@vger.kernel.org, tomk@rgmadvisors.com,
	Shawn Bohrer <sbohrer@rgmadvisors.com>
Subject: Re: [PATCH net-next 1/2] mlx4_en: Add PTP hardware clock
Date: Mon, 23 Dec 2013 19:48:46 +0100	[thread overview]
Message-ID: <20131223184845.GA4922@netboy> (raw)
In-Reply-To: <52B6E568.4030400@mellanox.com>

On Sun, Dec 22, 2013 at 03:13:12PM +0200, Hadar Hen Zion wrote:

> 2. Adding spin lock in the data path reduce performance by 15% when
> HW timestamping is enabled. I did some testing and replacing
> spin_lock_irqsave with read/write_lock_irqsave prevents the
> performance decrease.

Why do the spin locks cause such a bottleneck?

Is there really that much lock contention in your test?

Your figure of 15% seems awfully high. How did you arrive at that
figure?

Thanks,
Richard

  parent reply	other threads:[~2013-12-23 18:49 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-17 20:32 [PATCH net-next 0/2] mlx4_en: Add PTP support Shawn Bohrer
2013-12-17 20:32 ` [PATCH net-next 1/2] mlx4_en: Add PTP hardware clock Shawn Bohrer
2013-12-17 21:04   ` Or Gerlitz
2013-12-17 21:46     ` Shawn Bohrer
2013-12-18  7:59       ` Or Gerlitz
2013-12-18 15:03         ` Shawn Bohrer
2013-12-22 13:13   ` Hadar Hen Zion
2013-12-23 16:29     ` Shawn Bohrer
2013-12-23 16:59       ` Shawn Bohrer
2013-12-24 15:38         ` Hadar Hen Zion
2013-12-25 11:49           ` Richard Cochran
2013-12-23 18:48     ` Richard Cochran [this message]
2013-12-24 13:58       ` Hadar Hen Zion
2013-12-25 11:53         ` Richard Cochran
     [not found]           ` <CAKBbMu33zXkG4+S1kP6zB+4iKMNNoy=XVBtoqZZEkqurRsgvQw@mail.gmail.com>
2013-12-25 17:02             ` Richard Cochran
2013-12-26  8:26           ` Hadar Hen Zion
2013-12-26  8:33             ` Hadar Hen Zion
2013-12-26  9:17               ` Richard Cochran
2013-12-26 14:41                 ` Hadar Hen-Zion
2013-12-26 14:49                   ` Richard Cochran
2013-12-17 20:32 ` [PATCH net-next 2/2] mlx4_en: Only cycle port if HW timestamp config changes Shawn Bohrer

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