On Monday 12 November 2012 07:20 PM, Arnd Bergmann wrote: > On Monday 12 November 2012, vineet.gup...@synopsys.com wrote: >> endmenu # "Platform Board Configuration" >> >> +config ARC_CURR_IN_REG >> + bool "Dedicate Register r25 for current_task pointer" >> + default y >> + help >> + This reserved Register R25 to point to Current Task in >> + kernel mode. This saves memory access for each such access >> + > This looks like a useful feature if you have 32 GPRs, but why make it > optional? Are there cases where you would disable it?
Since it touched the low level guts of port, it made sense to start with a config option in initial implementation. But I've kept it that way since it annotates the code nicely and implicitly documents how to do this for any other register + data structure. > Another alternative to caching "current" would be to cache the per-cpu > offset, and calculate current from that one. Good tip - I'll add this to my TODO list - > Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
