On Wed, Feb 07, 2007 at 03:29:34PM +0900, Paul Mundt wrote: > On Tue, Feb 06, 2007 at 10:15:47PM -0800, David Rientjes wrote: > > Extracts the page table entry walker from the smaps-specific code in > > fs/proc/task_mmu.c. This will be used later for clearing the reference > > bits on pages to measure the number of pages accessed over a time period > > through /proc/pid/smaps. > > > I like the general idea of this patch set, however.. > > > Since the PTE walker is now extracted from the smaps code, > > smaps_pte_func() is invoked for each PTE in the VMA. Its behavior is > > identical to the existing implementation, except it is slightly slower > > because each PTE now invokes a function call. > > > Perhaps this is something that needs to be looked at more closely and > made more generic? There are many ranged page table walkers that aren't > so performance critical that the function call cost would cause too much > pain. ioremap_page_range() comes to mind, and there's bound to be others. > This would also help people to get the pte map/unmap right, which seems > to pop up from time to time as well..
I've been looking at a similar refactoring of other code and I think the way to go is a callback per block-of-PTEs with start and end pointers. That gets rid of most of the call indirection overhead. -- Mathematics is the supreme nostalgia of our time. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
