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 257D7C636D4 for ; Mon, 13 Feb 2023 18:21:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231295AbjBMSVs (ORCPT ); Mon, 13 Feb 2023 13:21:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229834AbjBMSVm (ORCPT ); Mon, 13 Feb 2023 13:21:42 -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 5F4D01ABD9 for ; Mon, 13 Feb 2023 10:21:39 -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 D98C5B8163A for ; Mon, 13 Feb 2023 18:21:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81CBFC433EF; Mon, 13 Feb 2023 18:21:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1676312496; bh=488/B8eNncEp4d0PU3FXJqGjfQ0swfDWR8Wx7qy6Unk=; h=Date:To:From:Subject:From; b=NZHmEAOKgnYGmr4VEe7bG95oBpnggK1kIjToreQCQ3xH6I+4PZZ+LmwEWNOqDpUMr GAS36kPanRgjfiVNPqX6id+aJwubMq1aRXJ/qUZjf5a4ZdsW6wMdA/6Q2V0iR4FZay 5ao2cLPX8weEE5+7cULA1YWGJ3Cys5SxPJH/FT1Y= Date: Mon, 13 Feb 2023 10:21:35 -0800 To: mm-commits@vger.kernel.org, ziy@nvidia.com, xhao@linux.alibaba.com, willy@infradead.org, shy828301@gmail.com, osalvador@suse.de, minchan@kernel.org, mike.kravetz@oracle.com, bharata@amd.com, baolin.wang@linux.alibaba.com, apopple@nvidia.com, 42.hyeyoo@gmail.com, ying.huang@intel.com, akpm@linux-foundation.org From: Andrew Morton Subject: + migrate_pages-separate-hugetlb-folios-migration.patch added to mm-unstable branch Message-Id: <20230213182136.81CBFC433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: migrate_pages: separate hugetlb folios migration has been added to the -mm mm-unstable branch. Its filename is migrate_pages-separate-hugetlb-folios-migration.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/migrate_pages-separate-hugetlb-folios-migration.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Huang Ying Subject: migrate_pages: separate hugetlb folios migration Date: Mon, 13 Feb 2023 20:34:37 +0800 This is a preparation patch to batch the folio unmapping and moving for the non-hugetlb folios. Based on that we can batch the TLB shootdown during the folio migration and make it possible to use some hardware accelerator for the folio copying. In this patch the hugetlb folios and non-hugetlb folios migration is separated in migrate_pages() to make it easy to change the non-hugetlb folios migration implementation. Link: https://lkml.kernel.org/r/20230213123444.155149-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" Reviewed-by: Baolin Wang Reviewed-by: Xin Hao Cc: Zi Yan Cc: Yang Shi Cc: Oscar Salvador Cc: Matthew Wilcox Cc: Bharata B Rao Cc: Alistair Popple Cc: Minchan Kim Cc: Mike Kravetz Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Andrew Morton --- --- a/mm/migrate.c~migrate_pages-separate-hugetlb-folios-migration +++ a/mm/migrate.c @@ -1414,6 +1414,8 @@ static inline int try_split_folio(struct return rc; } +#define NR_MAX_MIGRATE_PAGES_RETRY 10 + struct migrate_pages_stats { int nr_succeeded; /* Normal and large folios migrated successfully, in units of base pages */ @@ -1425,6 +1427,95 @@ struct migrate_pages_stats { }; /* + * Returns the number of hugetlb folios that were not migrated, or an error code + * after NR_MAX_MIGRATE_PAGES_RETRY attempts or if no hugetlb folios are movable + * any more because the list has become empty or no retryable hugetlb folios + * exist any more. It is caller's responsibility to call putback_movable_pages() + * only if ret != 0. + */ +static int migrate_hugetlbs(struct list_head *from, new_page_t get_new_page, + free_page_t put_new_page, unsigned long private, + enum migrate_mode mode, int reason, + struct migrate_pages_stats *stats, + struct list_head *ret_folios) +{ + int retry = 1; + int nr_failed = 0; + int nr_retry_pages = 0; + int pass = 0; + struct folio *folio, *folio2; + int rc, nr_pages; + + for (pass = 0; pass < NR_MAX_MIGRATE_PAGES_RETRY && retry; pass++) { + retry = 0; + nr_retry_pages = 0; + + list_for_each_entry_safe(folio, folio2, from, lru) { + if (!folio_test_hugetlb(folio)) + continue; + + nr_pages = folio_nr_pages(folio); + + cond_resched(); + + rc = unmap_and_move_huge_page(get_new_page, + put_new_page, private, + &folio->page, pass > 2, mode, + reason, ret_folios); + /* + * The rules are: + * Success: hugetlb folio will be put back + * -EAGAIN: stay on the from list + * -ENOMEM: stay on the from list + * -ENOSYS: stay on the from list + * Other errno: put on ret_folios list + */ + switch(rc) { + case -ENOSYS: + /* Hugetlb migration is unsupported */ + nr_failed++; + stats->nr_failed_pages += nr_pages; + list_move_tail(&folio->lru, ret_folios); + break; + case -ENOMEM: + /* + * When memory is low, don't bother to try to migrate + * other folios, just exit. + */ + stats->nr_failed_pages += nr_pages + nr_retry_pages; + return -ENOMEM; + case -EAGAIN: + retry++; + nr_retry_pages += nr_pages; + break; + case MIGRATEPAGE_SUCCESS: + stats->nr_succeeded += nr_pages; + break; + default: + /* + * Permanent failure (-EBUSY, etc.): + * unlike -EAGAIN case, the failed folio is + * removed from migration folio list and not + * retried in the next outer loop. + */ + nr_failed++; + stats->nr_failed_pages += nr_pages; + break; + } + } + } + /* + * nr_failed is number of hugetlb folios failed to be migrated. After + * NR_MAX_MIGRATE_PAGES_RETRY attempts, give up and count retried hugetlb + * folios as failed. + */ + nr_failed += retry; + stats->nr_failed_pages += nr_retry_pages; + + return nr_failed; +} + +/* * migrate_pages - migrate the folios specified in a list, to the free folios * supplied as the target for the page migration * @@ -1440,10 +1531,10 @@ struct migrate_pages_stats { * @ret_succeeded: Set to the number of folios migrated successfully if * the caller passes a non-NULL pointer. * - * The function returns after 10 attempts or if no folios are movable any more - * because the list has become empty or no retryable folios exist any more. - * It is caller's responsibility to call putback_movable_pages() to return folios - * to the LRU or free list only if ret != 0. + * The function returns after NR_MAX_MIGRATE_PAGES_RETRY attempts or if no folios + * are movable any more because the list has become empty or no retryable folios + * exist any more. It is caller's responsibility to call putback_movable_pages() + * only if ret != 0. * * Returns the number of {normal folio, large folio, hugetlb} that were not * migrated, or an error code. The number of large folio splits will be @@ -1457,7 +1548,7 @@ int migrate_pages(struct list_head *from int retry = 1; int large_retry = 1; int thp_retry = 1; - int nr_failed = 0; + int nr_failed; int nr_retry_pages = 0; int nr_large_failed = 0; int pass = 0; @@ -1474,38 +1565,45 @@ int migrate_pages(struct list_head *from trace_mm_migrate_pages_start(mode, reason); memset(&stats, 0, sizeof(stats)); + rc = migrate_hugetlbs(from, get_new_page, put_new_page, private, mode, reason, + &stats, &ret_folios); + if (rc < 0) + goto out; + nr_failed = rc; + split_folio_migration: - for (pass = 0; pass < 10 && (retry || large_retry); pass++) { + for (pass = 0; + pass < NR_MAX_MIGRATE_PAGES_RETRY && (retry || large_retry); + pass++) { retry = 0; large_retry = 0; thp_retry = 0; nr_retry_pages = 0; list_for_each_entry_safe(folio, folio2, from, lru) { + /* Retried hugetlb folios will be kept in list */ + if (folio_test_hugetlb(folio)) { + list_move_tail(&folio->lru, &ret_folios); + continue; + } + /* * Large folio statistics is based on the source large * folio. Capture required information that might get * lost during migration. */ - is_large = folio_test_large(folio) && !folio_test_hugetlb(folio); + is_large = folio_test_large(folio); is_thp = is_large && folio_test_pmd_mappable(folio); nr_pages = folio_nr_pages(folio); + cond_resched(); - if (folio_test_hugetlb(folio)) - rc = unmap_and_move_huge_page(get_new_page, - put_new_page, private, - &folio->page, pass > 2, mode, - reason, - &ret_folios); - else - rc = unmap_and_move(get_new_page, put_new_page, - private, folio, pass > 2, mode, - reason, &ret_folios); + rc = unmap_and_move(get_new_page, put_new_page, + private, folio, pass > 2, mode, + reason, &ret_folios); /* * The rules are: - * Success: non hugetlb folio will be freed, hugetlb - * folio will be put back + * Success: folio will be freed * -EAGAIN: stay on the from list * -ENOMEM: stay on the from list * -ENOSYS: stay on the from list @@ -1532,7 +1630,6 @@ split_folio_migration: stats.nr_thp_split += is_thp; break; } - /* Hugetlb migration is unsupported */ } else if (!no_split_folio_counting) { nr_failed++; } @@ -1626,8 +1723,8 @@ split_folio_migration: */ if (!list_empty(&split_folios)) { /* - * Move non-migrated folios (after 10 retries) to ret_folios - * to avoid migrating them again. + * Move non-migrated folios (after NR_MAX_MIGRATE_PAGES_RETRY + * retries) to ret_folios to avoid migrating them again. */ list_splice_init(from, &ret_folios); list_splice_init(&split_folios, from); _ Patches currently in -mm which might be from ying.huang@intel.com are migrate_pages-organize-stats-with-struct-migrate_pages_stats.patch migrate_pages-separate-hugetlb-folios-migration.patch migrate_pages-restrict-number-of-pages-to-migrate-in-batch.patch migrate_pages-split-unmap_and_move-to-_unmap-and-_move.patch migrate_pages-batch-_unmap-and-_move.patch migrate_pages-move-migrate_folio_unmap.patch migrate_pages-share-more-code-between-_unmap-and-_move.patch migrate_pages-batch-flushing-tlb.patch migrate_pages-move-thp-hugetlb-migration-support-check-to-simplify-code.patch