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 A2841C5475B for ; Mon, 11 Mar 2024 19:53:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3A4806B0117; Mon, 11 Mar 2024 15:53:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 354496B0118; Mon, 11 Mar 2024 15:53:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2434A6B0119; Mon, 11 Mar 2024 15:53:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 144E06B0117 for ; Mon, 11 Mar 2024 15:53:14 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id CF629809BD for ; Mon, 11 Mar 2024 19:53:13 +0000 (UTC) X-FDA: 81885807066.01.62E362E Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf06.hostedemail.com (Postfix) with ESMTP id B38EC180004 for ; Mon, 11 Mar 2024 19:53:11 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1710186792; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=r+6JeOFAMnBkSHGhfjueWZzcsWOuFKUzSrqXT1WUWho=; b=YLj4nieHhr9oU5ai1t0e79EDAmtpJi02yx9LrZ7Rd+KCvley8oaGt7sgze/RXj6S76VrU5 W+J/7K9HUc0K9uB3V0OiGmjfYBHSWctJ8sAyZsCOvfZOtZBepDUvT/EU6xv7XV4SJhKBqF OZ2MQMkZ7X218/qg4/zr46ZL5akVeiw= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1710186792; a=rsa-sha256; cv=none; b=ngPxDMs680c4YQNdnWY0H6gTa1OhObssPkQypq21+PDYy7uKWAjQCcC3g0UQJNcFMULG/f 6OMC9Xrau371Cs9esIFr8vuDdDH4LhB8LtenYYu0KBT7TJN9ECsAQ+WVz2gokAf6cDVM2i s7C4QRapcqlxleRBYv9epVAmu9+DCfo= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=none; spf=pass (imf06.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7414DFEC; Mon, 11 Mar 2024 12:53:47 -0700 (PDT) Received: from [10.57.68.246] (unknown [10.57.68.246]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 016063F73F; Mon, 11 Mar 2024 12:53:08 -0700 (PDT) Message-ID: <93f05080-1a31-4f59-828e-f5294561a99f@arm.com> Date: Mon, 11 Mar 2024 19:53:07 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/migrate: put dest folio on deferred split list if source was there. Content-Language: en-GB To: Zi Yan , linux-mm@kvack.org Cc: Andrew Morton , "Matthew Wilcox (Oracle)" , Yang Shi , Huang Ying , "Kirill A . Shutemov" , linux-kernel@vger.kernel.org References: <20240311193641.133981-1-zi.yan@sent.com> From: Ryan Roberts In-Reply-To: <20240311193641.133981-1-zi.yan@sent.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: B38EC180004 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: wc4e19gbohhr54g7ott1i3i4jjdkokb8 X-HE-Tag: 1710186791-397438 X-HE-Meta: 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 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: List-Subscribe: List-Unsubscribe: On 11/03/2024 19:36, Zi Yan wrote: > From: Zi Yan > > Commit 616b8371539a6 ("mm: thp: enable thp migration in generic path") > did not check if a THP is on deferred split list before migration, thus, > the destination THP is never put on deferred split list even if the source > THP might be. The opportunity of reclaiming free pages in a partially > mapped THP during deferred list scanning is lost, but no other harmful > consequence is present[1]. Checking source folio deferred split list > status before page unmapped and add destination folio to the list if > source was after migration. > > [1]: https://lore.kernel.org/linux-mm/03CE3A00-917C-48CC-8E1C-6A98713C817C@nvidia.com/ > > Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path") > Signed-off-by: Zi Yan > --- > mm/huge_memory.c | 22 ---------------------- > mm/internal.h | 23 +++++++++++++++++++++++ > mm/migrate.c | 26 +++++++++++++++++++++++++- > 3 files changed, 48 insertions(+), 23 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 9859aa4f7553..c6d4d0cdf4b3 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -766,28 +766,6 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) > return pmd; > } > > -#ifdef CONFIG_MEMCG > -static inline > -struct deferred_split *get_deferred_split_queue(struct folio *folio) > -{ > - struct mem_cgroup *memcg = folio_memcg(folio); > - struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); > - > - if (memcg) > - return &memcg->deferred_split_queue; > - else > - return &pgdat->deferred_split_queue; > -} > -#else > -static inline > -struct deferred_split *get_deferred_split_queue(struct folio *folio) > -{ > - struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); > - > - return &pgdat->deferred_split_queue; > -} > -#endif > - > void folio_prep_large_rmappable(struct folio *folio) > { > if (!folio || !folio_test_large(folio)) > diff --git a/mm/internal.h b/mm/internal.h > index d1c69119b24f..8fa36e84463a 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -1107,6 +1107,29 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, > unsigned long addr, pmd_t *pmd, > unsigned int flags); > > +#ifdef CONFIG_MEMCG > +static inline > +struct deferred_split *get_deferred_split_queue(struct folio *folio) > +{ > + struct mem_cgroup *memcg = folio_memcg(folio); > + struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); > + > + if (memcg) > + return &memcg->deferred_split_queue; > + else > + return &pgdat->deferred_split_queue; > +} > +#else > +static inline > +struct deferred_split *get_deferred_split_queue(struct folio *folio) > +{ > + struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); > + > + return &pgdat->deferred_split_queue; > +} > +#endif > + > + > /* > * mm/mmap.c > */ > diff --git a/mm/migrate.c b/mm/migrate.c > index 73a052a382f1..84ba1c65d20d 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -20,6 +20,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -1037,7 +1038,10 @@ static int move_to_new_folio(struct folio *dst, struct folio *src, > enum { > PAGE_WAS_MAPPED = BIT(0), > PAGE_WAS_MLOCKED = BIT(1), > - PAGE_OLD_STATES = PAGE_WAS_MAPPED | PAGE_WAS_MLOCKED, > + PAGE_WAS_ON_DEFERRED_LIST = BIT(2), > + PAGE_OLD_STATES = PAGE_WAS_MAPPED | > + PAGE_WAS_MLOCKED | > + PAGE_WAS_ON_DEFERRED_LIST, > }; > > static void __migrate_folio_record(struct folio *dst, > @@ -1168,6 +1172,17 @@ static int migrate_folio_unmap(new_folio_t get_new_folio, > folio_lock(src); > } > locked = true; > + if (folio_test_large_rmappable(src) && > + !list_empty(&src->_deferred_list)) { > + struct deferred_split *ds_queue = get_deferred_split_queue(src); > + > + spin_lock(&ds_queue->split_queue_lock); > + ds_queue->split_queue_len--; > + list_del_init(&src->_deferred_list); > + spin_unlock(&ds_queue->split_queue_lock); > + old_page_state |= PAGE_WAS_ON_DEFERRED_LIST; > + } > + > if (folio_test_mlocked(src)) > old_page_state |= PAGE_WAS_MLOCKED; > > @@ -1307,6 +1322,15 @@ static int migrate_folio_move(free_folio_t put_new_folio, unsigned long private, > if (old_page_state & PAGE_WAS_MAPPED) > remove_migration_ptes(src, dst, false); > > + if (old_page_state & PAGE_WAS_ON_DEFERRED_LIST) { > + struct deferred_split *ds_queue = get_deferred_split_queue(src); do you mean dst here? > + > + spin_lock(&ds_queue->split_queue_lock); > + ds_queue->split_queue_len++; > + list_add(&dst->_deferred_list, &ds_queue->split_queue); > + spin_unlock(&ds_queue->split_queue_lock); > + } > + > out_unlock_both: > folio_unlock(dst); > set_page_owner_migrate_reason(&dst->page, reason);