On Tue, Jul 01, 2014 at 02:00:32PM -0700, Dave Hansen wrote: > On 07/01/2014 10:07 AM, Naoya Horiguchi wrote: > > queue_pages_range() does page table walking in its own way now, but there > > is some code duplicate. This patch applies page table walker to reduce > > lines of code. > > > > queue_pages_range() has to do some precheck to determine whether we really > > walk over the vma or just skip it. Now we have test_walk() callback in > > mm_walk for this purpose, so we can do this replacement cleanly. > > queue_pages_test_walk() depends on not only the current vma but also the > > previous one, so queue_pages->prev is introduced to remember it. > > Hi Naoya, > > The previous version of this patch caused a performance regression which > was reported to you: > > http://marc.info/?l=linux-kernel&m=140375975525069&w=2 > > Has that been dealt with in this version somehow?
I believe so, in previous version we called ->pte_entry() callback for each pte entries, but in this version I stop doing this and most of works are done in ->pmd_entry() callback, so the number of function calls are reduced by about 1/512. And rather than that, I just cleaned up queue_pages_* without major behavioral changes, so the visible regression should be solved. Thanks, Naoya Horiguchi -- 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/
