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charset=utf-8 Content-Disposition: inline In-Reply-To: <20200423160546.GA389168@cmpxchg.org> Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000017, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Apr 23, 2020 at 12:05:46PM -0400, Johannes Weiner wrote: > On Thu, Apr 23, 2020 at 12:16:02PM +0900, Jaewon Kim wrote: > >=20 > >=20 > > On 2020=EB=85=84 04=EC=9B=94 22=EC=9D=BC 22:07, Johannes Weiner wrote= : > > > On Wed, Apr 22, 2020 at 05:48:15PM +0900, Jaewon Kim wrote: > > >> @@ -1295,11 +1295,15 @@ static unsigned long shrink_page_list(stru= ct list_head *page_list, > > >> */ > > >> if (page_mapped(page)) { > > >> enum ttu_flags flags =3D ttu_flags | TTU_BATCH_FLUSH; > > >> + bool lazyfree =3D PageAnon(page) && !PageSwapBacked(page); > > >> =20 > > >> if (unlikely(PageTransHuge(page))) > > >> flags |=3D TTU_SPLIT_HUGE_PMD; > > >> + > > >> if (!try_to_unmap(page, flags)) { > > >> stat->nr_unmap_fail +=3D nr_pages; > > >> + if (lazyfree && PageSwapBacked(page)) > > > This looks pretty strange, until you remember that try_to_unmap() > > > could SetPageSwapbacked again. > > > > > > This might be more obvious? > > > > > > was_swapbacked =3D PageSwapBacked(page); > > > if (!try_to_unmap(page, flags)) { > > > stat->nr_unmap_fail +=3D nr_pages; > > > if (!was_swapbacked && PageSwapBacked(page)) > > Hello Johannes, thank you for your comment. > >=20 > > The name can changed from layzyfree to was_swapbacked. > > By the way, did you mean removing PageAnon(page), too? It seems to be= OK, though. >=20 > I can't decide whether PageAnon() makes it clearer or not. But it's > not really needed for correctness. So feel free to keep what you had. Yub, PageAnon is redundant. > I would really just at least change bool lazyfree to was_lazyfree, It's better.