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From: Stephen Hemminger <stephen@networkplumber.org>
To: Wen-Chi Yang <wolkayang@gmail.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] rte_alarm: modify it to make it not to be affected by discontinuous jumps in the system time
Date: Tue, 13 Oct 2015 17:33:20 -0700	[thread overview]
Message-ID: <20151013173320.46e07232@xeon-e3> (raw)
In-Reply-To: <1433472396-18852-1-git-send-email-wolkayang@gmail.com>

On Fri,  5 Jun 2015 10:46:36 +0800
Wen-Chi Yang <wolkayang@gmail.com> wrote:

> Due to eal_alarm_callback() and rte_eal_alarm_set() use gettimeofday()
> to get the current time, and gettimeofday() is affected by jumps.
> 
> For example, set up a rte_alarm which will be triggerd next second (
> current time + 1 second) by rte_eal_alarm_set(). And the callback
> function of this rte_alarm sets up another rte_alarm which will be
> triggered next second (current time + 2 second).
> Once we change the system time when the callback function is triggered,
> it is possiblb that rte alarm functionalities work out of expectation.
> 
> Replace gettimeofday() with clock_gettime(CLOCK_MONOTONIC_RAW, &now)
> could avoid this phenomenon.
> 
> Signed-off-by: Wen-Chi Yang <wolkayang@gmail.com>

Agreed, this should be applied.
Does BSD version have same problem?

Acked-by: Stephen Hemminger <stephen@networkplumber.org>

  reply	other threads:[~2015-10-14  0:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-05  2:46 Wen-Chi Yang
2015-10-14  0:33 ` Stephen Hemminger [this message]
2015-10-14 12:09   ` Jay Rolette
2015-10-21 15:00     ` Thomas Monjalon
2015-10-21 14:57   ` Thomas Monjalon
2015-10-21 15:10   ` Thomas Monjalon

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