From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A889FC4332F for ; Tue, 13 Dec 2022 19:15:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236711AbiLMTPD (ORCPT ); Tue, 13 Dec 2022 14:15:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236330AbiLMTO3 (ORCPT ); Tue, 13 Dec 2022 14:14:29 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3B211028 for ; Tue, 13 Dec 2022 11:14:27 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 61D27B815B8 for ; Tue, 13 Dec 2022 19:14:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33585C433EF; Tue, 13 Dec 2022 19:14:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670958865; bh=+A016sYxaSG/q1QGBoJdS9q5imi3Rt/lWMe4htZ9ico=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=amY2ykOojrQ4Jx8/+f2rWFfU1kM8bAQ0G2oCuTiZZm3NYNh8y4h7/aSo/lYlxfmNo 1ApivF2IWFWlPLlSBb5Zsl3yF0ePB0SPdIqM5f/ScGaoSwzz3PQ81HuTPdI9n1oINi jxi+c13+rg2O9Zp5hgJTgt+vJez04N1+3ycjA2+31veH5L/TUuLWcVuFR6vTqHADzw hN4ohCP1dbKZC/xo0TXWopoN/Ex7SEDKjeOzSc4Q7ezaf5tuF8bDCryduRRFHYmZiE 8p3KWT0/ggmALc2HIClROyatr9C9ehvCrzCibhLC9+8k2zl4VzBB2EKlk/biPzwWon P90JhLcN53DTA== From: SeongJae Park To: Kefeng Wang Cc: Andrew Morton , David Hildenbrand , Oscar Salvador , SeongJae Park , linux-mm@kvack.org, linux-kernel@vger.kernel.org, damon@lists.linux.dev, vishal.moola@gmail.com, willy@infradead.org Subject: Re: [PATCH -next 2/8] mm: page_idle: Convert page idle to use folios Date: Tue, 13 Dec 2022 19:14:22 +0000 Message-Id: <20221213191422.138595-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221213092735.187924-3-wangkefeng.wang@huawei.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 13 Dec 2022 17:27:29 +0800 Kefeng Wang wrote: > This change and rename all page related function to use folio, > which save many compound_head() calls and kernel text. > > Signed-off-by: Kefeng Wang > --- > mm/page_idle.c | 91 ++++++++++++++++++++++++-------------------------- > 1 file changed, 44 insertions(+), 47 deletions(-) > > diff --git a/mm/page_idle.c b/mm/page_idle.c > index bc08332a609c..38641f94cf49 100644 > --- a/mm/page_idle.c > +++ b/mm/page_idle.c > @@ -19,34 +19,33 @@ > #define BITMAP_CHUNK_BITS (BITMAP_CHUNK_SIZE * BITS_PER_BYTE) > > /* > - * Idle page tracking only considers user memory pages, for other types of > - * pages the idle flag is always unset and an attempt to set it is silently > + * Idle folio tracking only considers user memory folios, for other types of > + * folios the idle flag is always unset and an attempt to set it is silently > * ignored. I think this might make future readers confused, as the code and comments will call this subsystem as Idle _folio_ tracking while the user interface and the document calls it as Idle _page_ tracking. > * > - * We treat a page as a user memory page if it is on an LRU list, because it is > - * always safe to pass such a page to rmap_walk(), which is essential for idle > - * page tracking. With such an indicator of user pages we can skip isolated > - * pages, but since there are not usually many of them, it will hardly affect > + * We treat a folio as a user memory folio if it is on an LRU list, because it is > + * always safe to pass such a folio to rmap_walk(), which is essential for idle > + * folio tracking. With such an indicator of user folios we can skip isolated > + * folios, but since there are not usually many of them, it will hardly affect > * the overall result. > * > - * This function tries to get a user memory page by pfn as described above. > + * This function tries to get a user memory folio by pfn as described above. > */ > -static struct page *page_idle_get_page(unsigned long pfn) > +static struct folio *folio_idle_get_folio(unsigned long pfn) > { > - struct page *page = pfn_to_online_page(pfn); > + struct folio *folio = pfn_to_online_folio(pfn); > > - if (!page || !PageLRU(page) || > - !get_page_unless_zero(page)) > + if (!folio || !folio_test_lru(folio) || !folio_try_get(folio)) > return NULL; As Matthew also mentioned, you changed the behavior. It looks like a right behavior if we call this function folio_idle_get_folio(), but it shouldn't. page_idle_get_folio() would be a better name in my humble opinion. So, unless we're gonna change the behavior of this subsystem (which wouldn't be the case as it would break users), I think it would be better to keep the name of this subsystem as Idle page tracking and avoid unnecessary renaming changes. Thanks, SJ