From: Matthew Wilcox <matthew@wil.cx>
To: David Brownell <david-b@pacbell.net>
Cc: linux-scsi@vger.kernel.org
Subject: Re: fix compile-time divide-by-zero in scsi_ioctl
Date: Wed, 27 Sep 2006 20:40:27 -0600 [thread overview]
Message-ID: <20060928024027.GW5017@parisc-linux.org> (raw)
In-Reply-To: <200609271628.27120.david-b@pacbell.net>
On Wed, Sep 27, 2006 at 04:28:26PM -0700, David Brownell wrote:
> On Wednesday 27 September 2006 1:27 pm, Matthew Wilcox wrote:
> > On Tue, Sep 26, 2006 at 08:48:48AM -0700, David Brownell wrote:
> > > This fixes a compiler-reported divide-by-zero when HZ < 100.
> >
> > Shouldn't we instead be using jiffies_to_clock_t? Thus:
>
> Could be ... the units in that function unclear to me though.
Me too, tbh. But the function looks right.
static inline clock_t jiffies_to_clock_t(long x)
{
#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
return x / (HZ / USER_HZ);
#else
u64 tmp = (u64)x * TICK_NSEC;
do_div(tmp, (NSEC_PER_SEC / USER_HZ));
return (long)tmp;
#endif
}
prev parent reply other threads:[~2006-09-28 2:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-26 15:48 fix compile-time divide-by-zero in scsi_ioctl David Brownell
2006-09-27 20:27 ` Matthew Wilcox
2006-09-27 23:28 ` David Brownell
2006-09-28 2:40 ` Matthew Wilcox [this message]
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