Jeremy Higdon wrote:
We don't actually have that problem on the Altix. All writes issued by CPU X will be ordered with respect to each other. But writes by CPU X and CPU Y will not be, unless an mmiowb() is done by the original CPU before the second CPU writes. I.e.CPU X writel CPU X writel CPU X mmiowb CPU Y writel ... Note that this implies some sort of locking. Also note that if in the above, CPU Y did the mmiowb, that would not work.
Hmmm, Then it's less bad than I thought - my apologies for the confusion. Would we be able to use Ben's trick of setting a per cpu flag in writel() then and checking that in spin unlock issuing the mmiowb() there if needed? Cheers, Jes _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
