On Wed, 29 Apr 2015 01:28:28 +0300 "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> wrote: > On Tue, Apr 28, 2015 at 03:14:20PM -0700, Andrew Morton wrote: > > On Mon, 27 Apr 2015 14:26:46 +0300 "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> wrote: > > > > > PageTrans* helpers are always-false if THP is disabled compile-time. > > > It means the fucntion will fail to detect hugetlb pages in this case. > > > > > > Let's use PageCompound() instead. With small tweak to how we calculate > > > next low_pfn it will make function ready to see tail pages. > > > > <scratches head> > > > > So this patch has no runtime effects at present? It is preparation for > > something else? > > I wrote this to fix bug I originally attributed to refcounting patchset, > but Sasha triggered the same bug on -next without the patchset applied: > > http://lkml.kernel.org/g/553EB993.7030401@xxxxxxxxxx Well why the heck didn't the changelog tell us this?!?!? > Now I think it's related to changing of PageLRU() behaviour on tail page > by my page flags patchset. So this patch is a bugfix against one of page-flags-trivial-cleanup-for-pagetrans-helpers.patch page-flags-introduce-page-flags-policies-wrt-compound-pages.patch page-flags-define-pg_locked-behavior-on-compound-pages.patch page-flags-define-behavior-of-fs-io-related-flags-on-compound-pages.patch page-flags-define-behavior-of-lru-related-flags-on-compound-pages.patch page-flags-define-behavior-slb-related-flags-on-compound-pages.patch page-flags-define-behavior-of-xen-related-flags-on-compound-pages.patch page-flags-define-pg_reserved-behavior-on-compound-pages.patch page-flags-define-pg_swapbacked-behavior-on-compound-pages.patch page-flags-define-pg_swapcache-behavior-on-compound-pages.patch page-flags-define-pg_mlocked-behavior-on-compound-pages.patch page-flags-define-pg_uncached-behavior-on-compound-pages.patch page-flags-define-pg_uptodate-behavior-on-compound-pages.patch page-flags-look-on-head-page-if-the-flag-is-encoded-in-page-mapping.patch mm-sanitize-page-mapping-for-tail-pages.patch include-linux-page-flagsh-rename-macros-to-avoid-collisions.patch Which one was the faulty patch? > PageLRU() on tail pages now reports true if > head page is on LRU. It means no we can go futher insede > isolate_migratepages_block() with tail page. -- 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>