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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44264C433EF for ; Sat, 19 Mar 2022 03:01:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A83848D0002; Fri, 18 Mar 2022 23:01:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A32AE8D0001; Fri, 18 Mar 2022 23:01:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8AD6E8D0002; Fri, 18 Mar 2022 23:01:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id 7702D8D0001 for ; Fri, 18 Mar 2022 23:01:25 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 3B80C20475 for ; Sat, 19 Mar 2022 03:01:25 +0000 (UTC) X-FDA: 79259634930.01.A2D950C Received: from mail-yb1-f174.google.com (mail-yb1-f174.google.com [209.85.219.174]) by imf27.hostedemail.com (Postfix) with ESMTP id B4F7140023 for ; Sat, 19 Mar 2022 03:01:24 +0000 (UTC) Received: by mail-yb1-f174.google.com with SMTP id j2so19063490ybu.0 for ; Fri, 18 Mar 2022 20:01:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=reWmP4Yyv0Mmo6tNnGsk6in1wc+xPjfMEBmvAdgMoDc=; b=QUlxX+ZAOMShNBy+QnsJ90r1OQ2VOtNFYnHa00oELbHAs+M54BOXEIoxDVlOVm/s8+ avht463rTX2aoWPIV+BF3uceUVZhaAzjTpjizML6oKG8iMMqogbfibpNdUf98CWNccr4 C+fxRZgXq2MlqUAHZxYCiVIfvISSh3lQLoo40Q4yzat43Ymskbt10DuKHxzG5udvK0od qL6a0umXrn4MC3BVDm/TzRjtG4++Mld7fHrAEWnXA+4pxW5VBLG7HLO5pfqIxcyR3WLd bxsuv20v9YTz/bGw93sfTvaPzQRSLLFu3tGQENkL00hciLjvIN/mZKLB9RuoDtYCfAig 1O4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=reWmP4Yyv0Mmo6tNnGsk6in1wc+xPjfMEBmvAdgMoDc=; b=bbwHvxZhmpUvGry6vGTN1Mk6h6nOvtrqZYOqgw1SLRBr0qsF2wkUzyRDamExdqM6Jk acTM7vw+4CstLVu5hUzEqJU4KdJAhh4n3HCeTtmtl8DEXg7TEynOnk0Yln4+MtZxpQa/ Myvoh1wVkbpCJUQR6l32qrCSDVIlotQ4guJl8bn2Zc7TvWaIjQ4ag5KGuJfqp3wh6Lpn YUrjJUy4yp8eD9X54gznlV7MIK68j+krO93MY3P1mxglm31xrhX1b7ZuOU42au+BKlob BmsZrti1fJXgZCYdXEKFT2sam2OCMrvdFP03+ESKVd4FJQ7Swnl44LEQ/B1FGnajT9Uj 2WLA== X-Gm-Message-State: AOAM533Fp50K8KZVKQLxoHbQGZGX5EnnaN1CKjpbgP0b/NuLBuAL3n2Z 5nhgvxU7DLp4b0uy9V+E1On2JeOg8G5zjWg1myk= X-Google-Smtp-Source: ABdhPJy0KTsGLEMJSC7xXZIBl4jfjABsDmKySWeDy3fUv2e8cUQp/c8hnHRCm9bEJfcTFciPSvLiI0NwgGoMEQ7JcNk= X-Received: by 2002:a25:fe04:0:b0:628:af01:f734 with SMTP id k4-20020a25fe04000000b00628af01f734mr13139432ybe.441.1647658883838; Fri, 18 Mar 2022 20:01:23 -0700 (PDT) MIME-Version: 1.0 References: <20220309021230.721028-1-yuzhao@google.com> <20220309021230.721028-7-yuzhao@google.com> In-Reply-To: <20220309021230.721028-7-yuzhao@google.com> From: Barry Song <21cnbao@gmail.com> Date: Sat, 19 Mar 2022 16:01:13 +1300 Message-ID: Subject: Re: [PATCH v9 06/14] mm: multi-gen LRU: minimal implementation To: Yu Zhao Cc: Andrew Morton , Linus Torvalds , Andi Kleen , Aneesh Kumar , Catalin Marinas , Dave Hansen , Hillf Danton , Jens Axboe , Jesse Barnes , Johannes Weiner , Jonathan Corbet , Matthew Wilcox , Mel Gorman , Michael Larabel , Michal Hocko , Mike Rapoport , Rik van Riel , Vlastimil Babka , Will Deacon , Ying Huang , LAK , Linux Doc Mailing List , LKML , Linux-MM , Kernel Page Reclaim v2 , x86 , Brian Geffon , Jan Alexander Steffens , Oleksandr Natalenko , Steven Barrett , Suleiman Souhlal , Daniel Byrne , Donald Carr , =?UTF-8?Q?Holger_Hoffst=C3=A4tte?= , Konstantin Kharlamov , Shuang Zhai , Sofia Trinh , Vaibhav Jain Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: B4F7140023 X-Rspam-User: Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=QUlxX+ZA; spf=pass (imf27.hostedemail.com: domain of 21cnbao@gmail.com designates 209.85.219.174 as permitted sender) smtp.mailfrom=21cnbao@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Stat-Signature: 81jcxnpie6oyyw4sbfxfz5nac7zepog3 X-Rspamd-Server: rspam07 X-HE-Tag: 1647658884-449472 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > +static int folio_inc_gen(struct lruvec *lruvec, struct folio *folio, bool reclaiming) > +{ > + unsigned long old_flags, new_flags; > + int type = folio_is_file_lru(folio); > + struct lru_gen_struct *lrugen = &lruvec->lrugen; > + int new_gen, old_gen = lru_gen_from_seq(lrugen->min_seq[type]); > + > + do { > + new_flags = old_flags = READ_ONCE(folio->flags); > + VM_BUG_ON_FOLIO(!(new_flags & LRU_GEN_MASK), folio); > + > + new_gen = ((new_flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1; > + new_gen = (old_gen + 1) % MAX_NR_GENS; new_gen is assigned twice, i assume you mean old_gen = ((new_flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1; new_gen = (old_gen + 1) % MAX_NR_GENS; or do you always mean new_gen = lru_gen_from_seq(min_seq) + 1? > + > + new_flags &= ~LRU_GEN_MASK; > + new_flags |= (new_gen + 1UL) << LRU_GEN_PGOFF; > + new_flags &= ~(LRU_REFS_MASK | LRU_REFS_FLAGS); > + /* for folio_end_writeback() */ > + if (reclaiming) > + new_flags |= BIT(PG_reclaim); > + } while (cmpxchg(&folio->flags, old_flags, new_flags) != old_flags); > + > + lru_gen_update_size(lruvec, folio, old_gen, new_gen); > + > + return new_gen; > +} > + Thanks Barry