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 49AD1C4332F for ; Wed, 28 Dec 2022 23:23:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231584AbiL1XXb (ORCPT ); Wed, 28 Dec 2022 18:23:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230050AbiL1XXR (ORCPT ); Wed, 28 Dec 2022 18:23:17 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A91C13E91 for ; Wed, 28 Dec 2022 15:23:16 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 351DC615FF for ; Wed, 28 Dec 2022 23:23:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A2CCC433D2; Wed, 28 Dec 2022 23:23:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1672269795; bh=N/3hFgLefXvsMIIuZU4ddFkL8KHt1QOQLe7r/WgHYVU=; h=Date:To:From:Subject:From; b=DoZA6kJkgPJXdbmXI13S9u9Q1GJ0F6kufQ7Y3WLWzLb+Uvc/rNOj6Ynumnxpz5GFl 23Q82y4LOwvK80x49bgEBKz2VLuFG8WkonhkvSKhHagTS9XUqJD6KmO20+j5wJMVlv 4SjblEjbUkYMK/cZYj6/rAhKJub/iUJCHRPuj2hA= Date: Wed, 28 Dec 2022 15:23:14 -0800 To: mm-commits@vger.kernel.org, ziy@nvidia.com, xhao@linux.alibaba.com, willy@infradead.org, shy828301@gmail.com, osalvador@suse.de, mgorman@techsingularity.net, bharata@amd.com, baolin.wang@linux.alibaba.com, apopple@nvidia.com, ying.huang@intel.com, akpm@linux-foundation.org From: Andrew Morton Subject: + migrate_pages-organize-stats-with-struct-migrate_pages_stats.patch added to mm-unstable branch Message-Id: <20221228232315.8A2CCC433D2@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: organize stats with struct migrate_pages_stats has been added to the -mm mm-unstable branch. Its filename is migrate_pages-organize-stats-with-struct-migrate_pages_stats.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/migrate_pages-organize-stats-with-struct-migrate_pages_stats.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: organize stats with struct migrate_pages_stats Date: Tue, 27 Dec 2022 08:28:52 +0800 Patch series "migrate_pages(): batch TLB flushing". Now, migrate_pages() migrate folios one by one, like the fake code as follows, for each folio unmap flush TLB copy restore map If multiple folios are passed to migrate_pages(), there are opportunities to batch the TLB flushing and copying. That is, we can change the code to something as follows, for each folio unmap for each folio flush TLB for each folio copy for each folio restore map The total number of TLB flushing IPI can be reduced considerably. And we may use some hardware accelerator such as DSA to accelerate the folio copying. So in this patch, we refactor the migrate_pages() implementation and implement the TLB flushing batching. Base on this, hardware accelerated folio copying can be implemented. If too many folios are passed to migrate_pages(), in the naive batched implementation, we may unmap too many folios at the same time. The possibility for a task to wait for the migrated folios to be mapped again increases. So the latency may be hurt. To deal with this issue, the max number of folios be unmapped in batch is restricted to no more than HPAGE_PMD_NR in the unit of page. That is, the influence is at the same level of THP migration. We use the following test to measure the performance impact of the patchset, On a 2-socket Intel server, - Run pmbench memory accessing benchmark - Run `migratepages` to migrate pages of pmbench between node 0 and node 1 back and forth. With the patch, the TLB flushing IPI reduces 99.1% during the test and the number of pages migrated successfully per second increases 291.7%. This patch (of 8): Define struct migrate_pages_stats to organize the various statistics in migrate_pages(). This makes it easier to collect and consume the statistics in multiple functions. This will be needed in the following patches in the series. Link: https://lkml.kernel.org/r/20221227002859.27740-1-ying.huang@intel.com Link: https://lkml.kernel.org/r/20221227002859.27740-2-ying.huang@intel.com Signed-off-by: "Huang, Ying" Cc: Zi Yan Cc: Yang Shi Cc: Baolin Wang Cc: Oscar Salvador Cc: Matthew Wilcox Cc: Bharata B Rao Cc: Alistair Popple Cc: Xin Hao Cc: Mel Gorman Signed-off-by: Andrew Morton --- --- a/mm/migrate.c~migrate_pages-organize-stats-with-struct-migrate_pages_stats +++ a/mm/migrate.c @@ -1413,6 +1413,14 @@ static inline int try_split_folio(struct return rc; } +struct migrate_pages_stats { + int nr_succeeded; + int nr_failed_pages; + int nr_thp_succeeded; + int nr_thp_failed; + int nr_thp_split; +}; + /* * migrate_pages - migrate the folios specified in a list, to the free folios * supplied as the target for the page migration @@ -1447,13 +1455,8 @@ int migrate_pages(struct list_head *from int large_retry = 1; int thp_retry = 1; int nr_failed = 0; - int nr_failed_pages = 0; int nr_retry_pages = 0; - int nr_succeeded = 0; - int nr_thp_succeeded = 0; int nr_large_failed = 0; - int nr_thp_failed = 0; - int nr_thp_split = 0; int pass = 0; bool is_large = false; bool is_thp = false; @@ -1463,9 +1466,11 @@ int migrate_pages(struct list_head *from LIST_HEAD(split_folios); bool nosplit = (reason == MR_NUMA_MISPLACED); bool no_split_folio_counting = false; + struct migrate_pages_stats stats; trace_mm_migrate_pages_start(mode, reason); + memset(&stats, 0, sizeof(stats)); split_folio_migration: for (pass = 0; pass < 10 && (retry || large_retry); pass++) { retry = 0; @@ -1519,9 +1524,9 @@ split_folio_migration: /* Large folio migration is unsupported */ if (is_large) { nr_large_failed++; - nr_thp_failed += is_thp; + stats.nr_thp_failed += is_thp; if (!try_split_folio(folio, &split_folios)) { - nr_thp_split += is_thp; + stats.nr_thp_split += is_thp; break; } /* Hugetlb migration is unsupported */ @@ -1529,7 +1534,7 @@ split_folio_migration: nr_failed++; } - nr_failed_pages += nr_pages; + stats.nr_failed_pages += nr_pages; list_move_tail(&folio->lru, &ret_folios); break; case -ENOMEM: @@ -1539,13 +1544,13 @@ split_folio_migration: */ if (is_large) { nr_large_failed++; - nr_thp_failed += is_thp; + stats.nr_thp_failed += is_thp; /* Large folio NUMA faulting doesn't split to retry. */ if (!nosplit) { int ret = try_split_folio(folio, &split_folios); if (!ret) { - nr_thp_split += is_thp; + stats.nr_thp_split += is_thp; break; } else if (reason == MR_LONGTERM_PIN && ret == -EAGAIN) { @@ -1563,7 +1568,7 @@ split_folio_migration: nr_failed++; } - nr_failed_pages += nr_pages + nr_retry_pages; + stats.nr_failed_pages += nr_pages + nr_retry_pages; /* * There might be some split folios of fail-to-migrate large * folios left in split_folios list. Move them back to migration @@ -1573,7 +1578,7 @@ split_folio_migration: list_splice_init(&split_folios, from); /* nr_failed isn't updated for not used */ nr_large_failed += large_retry; - nr_thp_failed += thp_retry; + stats.nr_thp_failed += thp_retry; goto out; case -EAGAIN: if (is_large) { @@ -1585,8 +1590,8 @@ split_folio_migration: nr_retry_pages += nr_pages; break; case MIGRATEPAGE_SUCCESS: - nr_succeeded += nr_pages; - nr_thp_succeeded += is_thp; + stats.nr_succeeded += nr_pages; + stats.nr_thp_succeeded += is_thp; break; default: /* @@ -1597,20 +1602,20 @@ split_folio_migration: */ if (is_large) { nr_large_failed++; - nr_thp_failed += is_thp; + stats.nr_thp_failed += is_thp; } else if (!no_split_folio_counting) { nr_failed++; } - nr_failed_pages += nr_pages; + stats.nr_failed_pages += nr_pages; break; } } } nr_failed += retry; nr_large_failed += large_retry; - nr_thp_failed += thp_retry; - nr_failed_pages += nr_retry_pages; + stats.nr_thp_failed += thp_retry; + stats.nr_failed_pages += nr_retry_pages; /* * Try to migrate split folios of fail-to-migrate large folios, no * nr_failed counting in this round, since all split folios of a @@ -1643,16 +1648,17 @@ out: if (list_empty(from)) rc = 0; - count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded); - count_vm_events(PGMIGRATE_FAIL, nr_failed_pages); - count_vm_events(THP_MIGRATION_SUCCESS, nr_thp_succeeded); - count_vm_events(THP_MIGRATION_FAIL, nr_thp_failed); - count_vm_events(THP_MIGRATION_SPLIT, nr_thp_split); - trace_mm_migrate_pages(nr_succeeded, nr_failed_pages, nr_thp_succeeded, - nr_thp_failed, nr_thp_split, mode, reason); + count_vm_events(PGMIGRATE_SUCCESS, stats.nr_succeeded); + count_vm_events(PGMIGRATE_FAIL, stats.nr_failed_pages); + count_vm_events(THP_MIGRATION_SUCCESS, stats.nr_thp_succeeded); + count_vm_events(THP_MIGRATION_FAIL, stats.nr_thp_failed); + count_vm_events(THP_MIGRATION_SPLIT, stats.nr_thp_split); + trace_mm_migrate_pages(stats.nr_succeeded, stats.nr_failed_pages, + stats.nr_thp_succeeded, stats.nr_thp_failed, + stats.nr_thp_split, mode, reason); if (ret_succeeded) - *ret_succeeded = nr_succeeded; + *ret_succeeded = stats.nr_succeeded; return rc; } _ 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_done-and-migrate_folio_unmap.patch migrate_pages-share-more-code-between-_unmap-and-_move.patch migrate_pages-batch-flushing-tlb.patch