From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: + mm-vmstat-add-events-for-thp-migration-without-split-fix-2.patch added to -mm tree Date: Thu, 09 Jul 2020 17:27:09 -0700 Message-ID: <20200710002709.j0TcbIj7X%akpm@linux-foundation.org> References: <20200703151445.b6a0cfee402c7c5c4651f1b1@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:60288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726311AbgGJA1L (ORCPT ); Thu, 9 Jul 2020 20:27:11 -0400 In-Reply-To: <20200703151445.b6a0cfee402c7c5c4651f1b1@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: anshuman.khandual@arm.com, daniel.m.jordan@oracle.com, hughd@google.com, jhubbard@nvidia.com, mm-commits@vger.kernel.org, n-horiguchi@ah.jp.nec.com, rdunlap@infradead.org, willy@infradead.org, ziy@nvidia.com The patch titled Subject: mm-vmstat-add-events-for-thp-migration-without-split-fix-2 has been added to the -mm tree. Its filename is mm-vmstat-add-events-for-thp-migration-without-split-fix-2.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-vmstat-add-events-for-thp-migration-without-split-fix-2.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-vmstat-add-events-for-thp-migration-without-split-fix-2.patch 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 and is updated there every 3-4 working days ------------------------------------------------------ From: Zi Yan Subject: mm-vmstat-add-events-for-thp-migration-without-split-fix-2 - Changed THP_MIGRATION_FAILURE as THP_MIGRATION_FAIL per John - Dropped all conditional 'if' blocks in migrate_pages() per Andrew and John - Updated migration events documentation per John - Updated thp_nr_pages variable as nr_subpages for an expected merge conflict - Moved all new THP vmstat events into CONFIG_MIGRATION - Updated Cc list with Documentation/ and tracing related addresses Link: http://lkml.kernel.org/r/C5E3C65C-8253-4638-9D3C-71A61858BB8B@nvidia.com Signed-off-by: Anshuman Khandual Cc: Zi Yan Cc: Daniel Jordan Cc: Hugh Dickins Cc: Matthew Wilcox Cc: Zi Yan Cc: John Hubbard Cc: Naoya Horiguchi Cc: Randy Dunlap Signed-off-by: Andrew Morton --- Documentation/vm/page_migration.rst | 40 +++++++++++++++----------- include/linux/vm_event_item.h | 6 +-- mm/migrate.c | 25 ++++++---------- mm/vmstat.c | 6 +-- 4 files changed, 40 insertions(+), 37 deletions(-) --- a/Documentation/vm/page_migration.rst~mm-vmstat-add-events-for-thp-migration-without-split-fix-2 +++ a/Documentation/vm/page_migration.rst @@ -253,24 +253,32 @@ which are function pointers of struct ad PG_isolated is alias with PG_reclaim flag so driver shouldn't use the flag for own purpose. -Quantifying Migration +Monitoring Migration ===================== -Following events can be used to quantify page migration. -1. PGMIGRATE_SUCCESS /* Normal page migration success */ -2. PGMIGRATE_FAIL /* Normal page migration failure */ -3. THP_MIGRATION_SUCCESS /* Transparent huge page migration success */ -4. THP_MIGRATION_FAILURE /* Transparent huge page migration failure */ -5. THP_MIGRATION_SPLIT /* Transparent huge page got split, retried */ - -THP_MIGRATION_SUCCESS is when THP is migrated successfully without getting -split into it's subpages. THP_MIGRATION_FAILURE is when THP could neither -be migrated nor be split. THP_MIGRATION_SPLIT is when THP could not -just be migrated as is but instead get split into it's subpages and later -retried as normal pages. THP events would also update normal page migration -statistics PGMIGRATE_SUCCESS and PGMIGRATE_FAILURE. These events will help -in quantifying and analyzing various THP migration events including both -success and failure cases. +The following events (counters) can be used to monitor page migration. + +1. PGMIGRATE_SUCCESS: Normal page migration success. Each count means that a + page was migrated. If the page was a non-THP page, then this counter is + increased by one. If the page was a THP, then this counter is increased by + the number of THP subpages. For example, migration of a single 2MB THP that + has 4KB-size base pages (subpages) will cause this counter to increase by + 512. + +2. PGMIGRATE_FAIL: Normal page migration failure. Same counting rules as for + _SUCCESS, above: this will be increased by the number of subpages, if it was + a THP. + +3. THP_MIGRATION_SUCCESS: A THP was migrated without being split. + +4. THP_MIGRATION_FAIL: A THP could not be migrated nor it could be split. + +5. THP_MIGRATION_SPLIT: A THP was migrated, but not as such: first, the THP had + to be split. After splitting, a migration retry was used for it's sub-pages. + +THP_MIGRATION_* events also update the appropriate PGMIGRATE_SUCCESS or +PGMIGRATE_FAIL events. For example, a THP migration failure will cause both +THP_MIGRATION_FAIL and PGMIGRATE_FAIL to increase. Christoph Lameter, May 8, 2006. Minchan Kim, Mar 28, 2016. --- a/include/linux/vm_event_item.h~mm-vmstat-add-events-for-thp-migration-without-split-fix-2 +++ a/include/linux/vm_event_item.h @@ -56,6 +56,9 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS #endif #ifdef CONFIG_MIGRATION PGMIGRATE_SUCCESS, PGMIGRATE_FAIL, + THP_MIGRATION_SUCCESS, + THP_MIGRATION_FAIL, + THP_MIGRATION_SPLIT, #endif #ifdef CONFIG_COMPACTION COMPACTMIGRATE_SCANNED, COMPACTFREE_SCANNED, @@ -95,9 +98,6 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS THP_ZERO_PAGE_ALLOC_FAILED, THP_SWPOUT, THP_SWPOUT_FALLBACK, - THP_MIGRATION_SUCCESS, - THP_MIGRATION_FAILURE, - THP_MIGRATION_SPLIT, #endif #ifdef CONFIG_MEMORY_BALLOON BALLOON_INFLATE, --- a/mm/migrate.c~mm-vmstat-add-events-for-thp-migration-without-split-fix-2 +++ a/mm/migrate.c @@ -1429,7 +1429,7 @@ int migrate_pages(struct list_head *from struct page *page; struct page *page2; int swapwrite = current->flags & PF_SWAPWRITE; - int rc, thp_n_pages; + int rc, nr_subpages; if (!swapwrite) current->flags |= PF_SWAPWRITE; @@ -1446,7 +1446,7 @@ retry: * during migration. */ is_thp = PageTransHuge(page); - thp_n_pages = thp_nr_pages(page); + nr_subpages = thp_nr_pages(page); cond_resched(); if (PageHuge(page)) @@ -1483,7 +1483,7 @@ retry: } if (is_thp) { nr_thp_failed++; - nr_failed += thp_n_pages; + nr_failed += nr_subpages; goto out; } nr_failed++; @@ -1498,7 +1498,7 @@ retry: case MIGRATEPAGE_SUCCESS: if (is_thp) { nr_thp_succeeded++; - nr_succeeded += thp_n_pages; + nr_succeeded += nr_subpages; break; } nr_succeeded++; @@ -1512,7 +1512,7 @@ retry: */ if (is_thp) { nr_thp_failed++; - nr_failed += thp_n_pages; + nr_failed += nr_subpages; break; } nr_failed++; @@ -1524,16 +1524,11 @@ retry: nr_thp_failed += thp_retry; rc = nr_failed; out: - if (nr_succeeded) - count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded); - if (nr_failed) - count_vm_events(PGMIGRATE_FAIL, nr_failed); - if (nr_thp_succeeded) - count_vm_events(THP_MIGRATION_SUCCESS, nr_thp_succeeded); - if (nr_thp_failed) - count_vm_events(THP_MIGRATION_FAILURE, nr_thp_failed); - if (nr_thp_split) - count_vm_events(THP_MIGRATION_SPLIT, nr_thp_split); + count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded); + count_vm_events(PGMIGRATE_FAIL, nr_failed); + 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, nr_thp_succeeded, nr_thp_failed, nr_thp_split, mode, reason); --- a/mm/vmstat.c~mm-vmstat-add-events-for-thp-migration-without-split-fix-2 +++ a/mm/vmstat.c @@ -1274,6 +1274,9 @@ const char * const vmstat_text[] = { #ifdef CONFIG_MIGRATION "pgmigrate_success", "pgmigrate_fail", + "thp_migration_success", + "thp_migration_fail", + "thp_migration_split", #endif #ifdef CONFIG_COMPACTION "compact_migrate_scanned", @@ -1320,9 +1323,6 @@ const char * const vmstat_text[] = { "thp_zero_page_alloc_failed", "thp_swpout", "thp_swpout_fallback", - "thp_migration_success", - "thp_migration_failure", - "thp_migration_split", #endif #ifdef CONFIG_MEMORY_BALLOON "balloon_inflate", _ Patches currently in -mm which might be from ziy@nvidia.com are mm-vmstat-add-events-for-thp-migration-without-split-fix-2.patch