On Mon, Dec 09, 2013 at 04:40:06PM +0000, Christoph Lameter wrote: >On Mon, 9 Dec 2013, Joonsoo Kim wrote: > >> First, we don't use error number in fail case. Call-path related to >> new_page_node() is shown in the following. >> >> do_move_page_to_node_array() -> migrate_pages() -> unmap_and_move() >> -> new_page_node() >> >> If unmap_and_move() failed, migrate_pages() also returns err, and then >> do_move_page_to_node_array() skips to set page's status to user buffer. >> So we don't need to set error number to each pages on failure case. > >I dont get this. new_page_node() sets the error condition in the >page_to_node array before this patch. There is no post processing in >do_move_page_to_node_array(). The function simply returns and relies on >new_page_node() to have set the page status. do_move_pages() then returns >the page status back to userspace. How does the change preserve these >diagnostics? > Agreed. >> Next, we don't need to set node id of the new page in unmap_and_move(), >> since it cannot be different with pm->node. In new_page_node(), we always >> try to allocate the page in exact node by referencing pm->node. So it is >> sufficient to set node id of the new page in new_page_node(), instead of >> unmap_and_move(). > >Thats a good thought. Agreed. > > >-- >To unsubscribe, send a message with 'unsubscribe linux-mm' in >the body to majordomo@xxxxxxxxx. For more info on Linux MM, >see: http://www.linux-mm.org/ . >Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>