On Tue, 31 Mar 2015 17:35:34 +0300 "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> wrote: > On Tue, Mar 31, 2015 at 08:11:02AM -0500, Christoph Lameter wrote: > > On Tue, 31 Mar 2015, Kirill A. Shutemov wrote: > > > > > Let's use PageAnon() and PageKsm() helpers instead. It helps readability > > > and makes page_anon_vma() work correctly on tail pages. > > > > But it adds a branch due to the use of ||. > > Which caller is hot enough to care? > It's a surprisingly expensive patch. text data bss dec hex filename 19984 1153 15192 36329 8de9 mm/ksm.o-before 20028 1153 15216 36397 8e2d mm/ksm.o-after 14728 116 5168 20012 4e2c mm/rmap.o-before 14763 116 5192 20071 4e67 mm/rmap.o-after 25723 1417 9776 36916 9034 mm/swapfile.o-before 25769 1417 9800 36986 907a mm/swapfile.o-after 197 bytes more text+bss, 125 bytes more text. (Why the heck do changes like this allegedly affect bss size?) -- 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>