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From: "Robert P. J. Day" <rpjday@crashcourse.ca>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: backwards busy wait using "time_before()"??
Date: Thu, 31 Dec 2009 11:40:42 -0500 (EST)	[thread overview]
Message-ID: <alpine.LFD.2.00.0912311136560.3596@localhost> (raw)


  if this is an idiotic question, i'll blame it on the fact that
there's only decaf left in the house.

  from drivers/spi/spi_stmp.c:

   #define busy_wait(cond)                                              \
        ({                                                              \
        unsigned long end_jiffies = jiffies + STMP_SPI_TIMEOUT;         \
        bool succeeded = false;                                         \
        do {                                                            \
                if (cond) {                                             \
                        succeeded = true;                               \
                        break;                                          \
                }                                                       \
                cpu_relax();                                            \
        } while (time_before(end_jiffies, jiffies));                    \
        succeeded;                                                      \
        })


  is it just me, or do those arguments to time_before() look
backwards?

rday
--

========================================================================
Robert P. J. Day                               Waterloo, Ontario, CANADA

            Linux Consulting, Training and Kernel Pedantry.

Web page:                                          http://crashcourse.ca
Twitter:                                       http://twitter.com/rpjday
========================================================================

             reply	other threads:[~2009-12-31 16:41 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-31 16:40 Robert P. J. Day [this message]
2009-12-31 19:23 ` backwards busy wait using "time_before()"?? Robert P. J. Day
2010-01-01 15:17 ` Andi Kleen

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