On 16.09.2013, at 22:29, Benjamin Herrenschmidt wrote: > On Fri, 2013-09-06 at 13:22 +1000, Paul Mackerras wrote: >> POWER7 and later IBM server processors have a register called the >> Program Priority Register (PPR), which controls the priority of >> each hardware CPU SMT thread, and affects how fast it runs compared >> to other SMT threads. This priority can be controlled by writing to >> the PPR or by use of a set of instructions of the form or rN,rN,rN >> which are otherwise no-ops but have been defined to set the priority >> to particular levels. >> >> This adds code to context switch the PPR when entering and exiting >> guests and to make the PPR value accessible through the SET/GET_ONE_REG >> interface. When entering the guest, we set the PPR as late as >> possible, because if we are setting a low thread priority it will >> make the code run slowly from that point on. Similarly, the >> first-level interrupt handlers save the PPR value in the PACA very >> early on, and set the thread priority to the medium level, so that >> the interrupt handling code runs at a reasonable speed. >> >> Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx> > > Acked-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> > > Alex, can you take this via your tree ? Yes, on the next respin :). Or is this one urgent? Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
