On Wed, Nov 04, 2015 at 04:00:57PM +0100, Vlastimil Babka wrote: > The information in /sys/kernel/debug/page_owner includes the migratetype > declared during the page allocation via gfp_flags. This is also checked against > the pageblock's migratetype, and reported as Fallback allocation if these two > differ (although in fact fallback allocation is not the only reason why they > can differ). > > However, the migratetype actually printed is the one of the pageblock, not of > the page itself, so it's the same for all pages in the pageblock. This is > apparently a bug, noticed when working on other page_owner improvements. Fixed. We can guess page migratetype through gfp_mask output although it isn't easy task for now. But, there is no way to know pageblock migratetype. I used this to know how memory is fragmented. Thanks. > > Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> > --- > mm/page_owner.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/page_owner.c b/mm/page_owner.c > index 983c3a1..a9f16b8 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -113,7 +113,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, > "PFN %lu Block %lu type %d %s Flags %s%s%s%s%s%s%s%s%s%s%s%s\n", > pfn, > pfn >> pageblock_order, > - pageblock_mt, > + page_mt, > pageblock_mt != page_mt ? "Fallback" : " ", > PageLocked(page) ? "K" : " ", > PageError(page) ? "E" : " ", > -- > 2.6.2 > > -- > 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>