On Wed, Nov 24, 2021 at 12:12 PM Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> wrote: > > On Tue, Nov 23, 2021 at 11:09:16AM -0800, Shakeel Butt wrote: > > The deferred THPs are split on memory pressure through shrinker > > callback and splitting of THP during reclaim can fail for several > > reasons like unable to lock the THP, under writeback or unexpected > > number of pins on the THP. Such pages are put back on the deferred split > > list for consideration later. However kernel does not update the > > deferred queue size on putting back the pages whose split was failed. > > This patch fixes that. > > Hm. No. split_huge_page_to_list() updates the queue size on split success. > Right. This is really convoluted. split_huge_page_to_list() is just assuming that if the given page is on a deferred list then it must be on the list returned by get_deferred_split_queue(page). The interaction of move_charge and deferred split seems broken. Andrew, can you please drop this patch?
