![]() | |||||||||||||
Messages in this thread |
On Tue, 2008-02-26 at 16:29 +0100, Miklos Szeredi wrote: > > > mm-page_file_methods.patch > > > > > > This makes page_offset and others more expensive by adding a > > > conditional jump to a function call that is not usually made. > > > > > > Why do swap pages have a different index to everyone else? > > > > Because the page->index of an anonymous page is related to its (anon)vma > > so that it satisfies the constraints for vm_normal_page(). > > > > The index in the swap file it totally unrelated and quite random. Hence > > the swap-cache uses page->private to store it in. > > Yeah, and putting the condition into page_offset() will confuse code > which uses it for finding the offset in the VMA or in a tmpfs file. > > So why not just have a separate page_swap_offset() function, used > exclusively by swap_in/out()? Ah, we can do the page_file_offset() to match page_file_index() and page_file_mapping(). And convert NFS to use page_file_offset() where appropriate, as I already did for these others. That would sort out the mess, right? | ||||||||||||
| Last update: 2008-02-26 16:47 [W:0.911 / U:0.010 seconds] ©2003-2008 Jasper Spaans | |||||||||||||