On Thu, Jul 26, 2012 at 05:55:09PM +0300, Avi Kivity wrote: > On 07/26/2012 05:16 PM, Eduardo Habkost wrote: > >> > > >> > It's possible to replace the atomic read of CountCPUs with the bitmap > >> > weight > >> > calculation on the loop, but: is it really worth it? > >> > > >> Why not? This eliminates one more global state. > > > > Maybe we can simply make it stop being global and be used only by the > > smp.c initialization code? > > > > Even if the variable didn't exist yet, I think I would add it myself: > > it's simpler and more efficient to calculate the bitmap weight once, > > while filling the bitmap, than recalculating it every time on the > > while(cmos_smp_count) loop. > > So you're spinning more efficiently?
No, coding more efficiently. I'm lazy. :-) I don't want to risk breaking that part of the code to save 2 bytes of memory. It's possible to impement it reliably, yes, but it's also very easy to introduce a subtle bug, so why touch something that works perfectly just to save 2 bytes? -- Eduardo