Re: [RFC][PATCH] sard changes for 2.5.34

Randy.Dunlap (rddunlap@osdl.org)
Wed, 18 Sep 2002 10:54:39 -0700 (PDT)


On Sat, 14 Sep 2002, Lev Makhlis wrote:

| > +#define MSEC(x) ((x) * 1000 / HZ)
|
| Perhaps it would be better to report the times in ticks using
| jiffies_to_clock_t(), and let the userland do further conversions?
| The macro above has an overflow problem, it creates a counter
| that wraps at 2^32 / HZ (instead of 2^32), and theoretically, the
| userland doesn't even know what the internal HZ is. The overflow
| can be avoided with something like
| #define MSEC(x) (((x) / HZ) * 1000 + ((x) % HZ) * 1000 / HZ)
| but I think it would be cleaner just to change the units to ticks,
| especially if we're moving it to a different file and procps will
| need to be changed anyway.

Thanks for pointing this out.

I'd rather not expose more ticks in /proc, so for now
I'll ask Rick to use this #define for MSEC, which does
indeed work nicely.

-- 
~Randy
"Linux is not a research project. Never was, never will be."
  -- Linus, 2002-09-02

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