On 11/07/2017 03:54 PM, Christopher Lameter wrote: > On Tue, 7 Nov 2017, Yisheng Xie wrote: > >> On 2017/11/6 23:29, Christopher Lameter wrote: >>> On Mon, 6 Nov 2017, Vlastimil Babka wrote: >>> >>>> I'm not sure what exactly is the EPERM intention. Should really the >>>> capability of THIS process override the cpuset restriction of the TARGET >>>> process? Maybe yes. Then, does "insufficient privilege (CAP_SYS_NICE) to >>> >>> CAP_SYS_NICE never overrides cpuset restrictions. The cap can be used to >>> migrate pages that are *also* mapped by other processes (and thus move >>> pages of another process which may have different cpu set restrictions!). >> >> So you means the specified nodes should be a subset of target cpu set, right? > > The specified nodes need to be part of the *current* cpu set. > > Migrate pages moves the pages of a single process there is no TARGET > process. migrate_pages(2) takes a pid argument "migrate_pages() attempts to move all pages of the process pid that are in memory nodes old_nodes to the memory nodes in new_nodes. " > Thus thehe *target* nodes need to be a subset of the current cpu set. > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-api" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
