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 A1CE2C54E66 for ; Tue, 12 Mar 2024 07:27:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1B4128D001A; Tue, 12 Mar 2024 03:27:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 165308D0017; Tue, 12 Mar 2024 03:27:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 02B1D8D001A; Tue, 12 Mar 2024 03:27:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id E856A8D0017 for ; Tue, 12 Mar 2024 03:27:23 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 7764C4103A for ; Tue, 12 Mar 2024 07:27:23 +0000 (UTC) X-FDA: 81887556366.15.CF2E2CD Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by imf12.hostedemail.com (Postfix) with ESMTP id DE99B40007 for ; Tue, 12 Mar 2024 07:27:19 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b=l0x0fnUH; dmarc=pass (policy=none) header.from=linux.alibaba.com; spf=pass (imf12.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.132 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1710228441; 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:dkim-signature; bh=kSSt8SHpYapetnfBjwiq6UQNHHnNk1Xqt0pSKtWzsiU=; b=NLYynvtl4BD7v14/AyfPZRBW1RiUhTSUbj/vPw15Zzo2BaZRcW8LSpJG6dgD1Kgf2qvNZ6 nJd7jBcV08i3X1BFCZeAj0f4FBNfw5XvqLCyDZVFEohUPqWQg7VVUDb2SpMquu31XSjtll JbbyCnq81HS5AA/Kr6Q7dRKu+RwHjPM= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b=l0x0fnUH; dmarc=pass (policy=none) header.from=linux.alibaba.com; spf=pass (imf12.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.132 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1710228441; a=rsa-sha256; cv=none; b=urLp/AHIwC+btBSrfaBYls+fcz1Z5r2MP4+9DquL+1Vl+tFR58jR3cJenFjPHOpbj42wfK kmkxWYYvxLD5FGow8Ayqvqdj0+525RYlOTbceOQadQIIUmrRh+gPAmXOgDcKFkatLpt4+i u9y3auqqph/YDNS+NzqvA8iyUmN3WK8= DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1710228436; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=kSSt8SHpYapetnfBjwiq6UQNHHnNk1Xqt0pSKtWzsiU=; b=l0x0fnUHJtFA9/FFuzQPZwjSAB3+iiQqyEpghmM9njFPKgKfnjylkhTCOD5VV+c2qVivE/ZPPpyyOWOehYdC2NTxZImMrKGt1NX09Zm0Nz7jJ3FX+hXHAJ54lL1N5p6F+xtmTolMgILKACC6z3Lm5hvYLqpGLhnJkBweW+B1tl0= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046051;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---0W2KyR9a_1710228432; Received: from 30.97.56.54(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0W2KyR9a_1710228432) by smtp.aliyun-inc.com; Tue, 12 Mar 2024 15:27:14 +0800 Message-ID: <081dc7bb-ae60-4a38-b9c8-560280cf5cf8@linux.alibaba.com> Date: Tue, 12 Mar 2024 15:27:12 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mm/migrate: put dest folio on deferred split list if source was there. To: Zi Yan , linux-mm@kvack.org Cc: Andrew Morton , "Matthew Wilcox (Oracle)" , Yang Shi , Huang Ying , "Kirill A . Shutemov" , Ryan Roberts , linux-kernel@vger.kernel.org References: <20240311195848.135067-1-zi.yan@sent.com> From: Baolin Wang In-Reply-To: <20240311195848.135067-1-zi.yan@sent.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: DE99B40007 X-Stat-Signature: xsoidzu4xq56wco8taaybiqkby5u7t3i X-HE-Tag: 1710228439-736030 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 2024/3/12 03:58, 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/ > > From v1: > 1. Used dst to get correct deferred split list after migration > (per Ryan Roberts). > > 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..591e65658535 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) && IMO, you should check folio_test_large() before calling folio_test_large_rmappable(), since the PG_large_rmappable flag is stored in the first tail page. > + !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(dst); > + > + 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);