Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH] I3 sched tweaks... | Date | Thu, 17 Jan 2002 14:37:09 +1100 |
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In message <Pine.LNX.4.33.0201162343290.18971-100000@localhost.localdomain> you write: > > On Wed, 16 Jan 2002, Rusty Russell wrote: > > > > > 4) scheduler_tick needs no args (p is always equal to current). > > > > > > i have not taken this part. We have 'current' calculated in > > > update_process_times(), so why not pass it along to the scheduler_tick() > > > function? > > > > Because it's redundant. It's *always* p == current (and the code > > assumes this!), but I had to grep the callers to find out. > > we pass pointers across functions regularly, even if the pointer could be > calculated within the function. We do this in the timer code too.
Look at it semantically: scheduler_tick() is just a function called regularly for scheduler maintenance. It might need the CPU number, the runqueue length, or phase of the moon: the caller shouldn't care.
If it was a static fn, maybe this optimization makes sense. But it's an interface wart, and the "optimization" is utterly marginal anyway.
That said, I never would have sent such a trivial patch by itself: I can't believe how many keystrokes were wasted over this issue!
Rusty. -- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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