Messages in this thread | | | From | Paul Mackerras <> | Date | Thu, 17 Jan 2002 08:31:51 +1100 (EST) | Subject | Re: [PATCH] I3 sched tweaks... |
| |
Ingo Molnar writes:
> It's > slightly cheaper to pass an already existing (calculated) 'current' > pointer over to another function, instead of calculating it once more in > that function.
On x86 that's true; many other architectures - alpha, ia64, m68k, mips, mips64, parisc, ppc, ppc64, sparc, sparc64 - keep current in a register already and thus it is slightly more expensive to pass it as a parameter instead of just using current in the function.
Either way surely the cost is tiny, and the maintainability considerations should prevail. Having a function which takes a task_struct * parameter which _has_ to be current sounds to me like an invitation for somebody to get it wrong down the track.
Paul. - 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/
| |