On Thu, 2 Apr 2015 01:02:46 +0300 "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> wrote: > On Wed, Apr 01, 2015 at 12:57:45PM -0700, Andrew Morton wrote: > > On Wed, 1 Apr 2015 14:50:54 +0300 "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> wrote: > > > > > >From adc384977898173d65c2567fc5eb421da9b272e0 Mon Sep 17 00:00:00 2001 > > > From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> > > > Date: Wed, 1 Apr 2015 14:33:56 +0300 > > > Subject: [PATCH] mm: uninline and cleanup page-mapping related helpers > > > > > > Most-used page->mapping helper -- page_mapping() -- has already > > > uninlined. Let's uninline also page_rmapping() and page_anon_vma(). > > > It saves us depending on configuration around 400 bytes in text: > > > > > > text data bss dec hex filename > > > 660318 99254 410000 1169572 11d8a4 mm/built-in.o-before > > > 659854 99254 410000 1169108 11d6d4 mm/built-in.o > > > > Well, code size isn't the only thing to care about. Some functions > > really should be inlined for performance reasons even if that makes the > > overall code larger. But the changes you're proposing here look OK to > > me. > > > > > As side effect page_anon_vma() now works properly on tail pages. > > > > Let's fix the bug in a separate patch, please. One which can be > > backported to earlier kernels if that should be needed. ie: it should > > precede any uninlining. > > The bug is not triggerable in current upsteam. AFAIK, we don't call > page_anon_vma() on tail pages of THP, since we don't map THP with PTEs > yet. For rest of cases we will get NULL, which is valid answer. argh. It rather helps if you can tell me when this happens (and which patch it fixes). I sometimes spend quite a bit of time runnnig around in circles wondering what the heck tree/patch just got fixed. > Do you still want "page = compound_head(page);" line in separate patch? I think that would be best. That way the offending patch gets fixed and doesn't get bundled up with an unrelated change. -- 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>