On 02/18/2010 11:48 AM, Christoph Lameter wrote: >> >> Yes, and I have repeatedly requested that we allocate the memory on the >> first up of a disabled CPU rather than eagerly, but in *most* >> configurations the amount is relatively small. > > The size of the static per cpu segment is likely around 30k and you will > likely add another 30k in dynamic allocations. > > As I have also repeatedly stated: Dynamic percpu data allocation when > onlining / offlining processors will complicate locking (cannot rely on > percpu be present anymore) and introduce numerous additional > hotplug notifiers into subsystems. I did state explicitly "on first up". Trying to free it would be insane. There are a couple of subsystems which are percpu memory pigs... so far it's not clear any of them actually matters in a production kernel. 60K * 16 phantom processors is still ~ 1 MB, which probably isn't enough to worry about but isn't great. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
