On Fri, Jun 1, 2012 at 9:40 PM, Hugh Dickins <hughd@xxxxxxxxxx> wrote: > > Move the lock after the loop, I think you meant. Well, I wasn't sure if anything inside the loop might need it. I don't *think* so, but at the same time, what protects "page_order(page)" (or, indeed PageBuddy()) from being stable while that loop content uses them? I don't understand that code at all. It does that crazy iteration over page, and changes "page" in random ways, and then finishes up with a totally new "page" value that is some random thing that is *after* the end_page thing. WHAT? The code makes no sense. It tests all those pages within the page-block, but then after it has done all those tests, it does the final set_pageblock_migratetype(..) move_freepages_block(..) using a page that is *beyond* the pageblock (and with the whole page_order() thing, who knows just how far beyond it?) It looks entirely too much like random-monkey code to me. Linus -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>