Hi, I have a few comments on this. a. I reported it very early and should have been Cc-ed. b. A patch that applies to mmotm or linux-next would have been better than a full replacement patch. c. I tried replacing what I believe is the correct/same patch file in mmotm and still have build errors. (more below) On 7/9/20 2:39 AM, Anshuman Khandual wrote: > --- > Applies on 5.8-rc4. > > Changes in V4: > > - 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 > > Changes in V3: (https://patchwork.kernel.org/patch/11647237/) > > - Formatted new events documentation with 'fmt' tool per Matthew > - Made events universally available i.e dropped ARCH_ENABLE_THP_MIGRATION > - Added THP_MIGRATION_SPLIT > - Updated trace_mm_migrate_pages() with THP events > - Made THP events update normal page migration events as well > > Changes in V2: (https://patchwork.kernel.org/patch/11586893/) > > - Dropped PMD reference both from code and commit message per Matthew > - Added documentation and updated the commit message per Daniel > > Changes in V1: (https://patchwork.kernel.org/patch/11564497/) > > - Changed function name as thp_pmd_migration_success() per John > - Folded in a fix (https://patchwork.kernel.org/patch/11563009/) from Hugh > > Changes in RFC V2: (https://patchwork.kernel.org/patch/11554861/) > > - Decopupled and renamed VM events from their implementation per Zi and John > - Added THP_PMD_MIGRATION_FAILURE VM event upon allocation failure and split > > Changes in RFC V1: (https://patchwork.kernel.org/patch/11542055/) > > Documentation/vm/page_migration.rst | 27 +++++++++++++++ > include/linux/vm_event_item.h | 3 ++ > include/trace/events/migrate.h | 17 ++++++++-- > mm/migrate.c | 52 ++++++++++++++++++++++++----- > mm/vmstat.c | 3 ++ > 5 files changed, 91 insertions(+), 11 deletions(-) > > diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h > index 24fc7c3ae7d6..2e6ca53b9bbd 100644 > --- a/include/linux/vm_event_item.h > +++ b/include/linux/vm_event_item.h > @@ -56,6 +56,9 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT, > #endif > #ifdef CONFIG_MIGRATION > PGMIGRATE_SUCCESS, PGMIGRATE_FAIL, > + THP_MIGRATION_SUCCESS, > + THP_MIGRATION_FAIL, > + THP_MIGRATION_SPLIT, These 3 new symbols are still only present if CONFIG_MIGRATION=y, but the build errors are using these symbols even when CONFIG_MIGRATION is not set. > #endif > #ifdef CONFIG_COMPACTION > COMPACTMIGRATE_SCANNED, COMPACTFREE_SCANNED, > diff --git a/mm/migrate.c b/mm/migrate.c > index f37729673558..c706e3576cfc 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1429,22 +1429,35 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > enum migrate_mode mode, int reason) > { > int retry = 1; > + int thp_retry = 1; > int nr_failed = 0; > int nr_succeeded = 0; > + int nr_thp_succeeded = 0; > + int nr_thp_failed = 0; > + int nr_thp_split = 0; > int pass = 0; > + bool is_thp = false; > struct page *page; > struct page *page2; > int swapwrite = current->flags & PF_SWAPWRITE; > - int rc; > + int rc, nr_subpages; > > if (!swapwrite) > current->flags |= PF_SWAPWRITE; > > - for(pass = 0; pass < 10 && retry; pass++) { > + for (pass = 0; pass < 10 && (retry || thp_retry); pass++) { > retry = 0; > + thp_retry = 0; > > list_for_each_entry_safe(page, page2, from, lru) { > retry: > + /* > + * THP statistics is based on the source huge page. > + * Capture required information that might get lost > + * during migration. > + */ > + is_thp = PageTransHuge(page); > + nr_subpages = hpage_nr_pages(page); > cond_resched(); > > if (PageHuge(page)) > @@ -1475,15 +1488,30 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > unlock_page(page); > if (!rc) { > list_safe_reset_next(page, page2, lru); > + nr_thp_split++; > goto retry; > } > } > + if (is_thp) { > + nr_thp_failed++; > + nr_failed += nr_subpages; > + goto out; > + } > nr_failed++; > goto out; > case -EAGAIN: > + if (is_thp) { > + thp_retry++; > + break; > + } > retry++; > break; > case MIGRATEPAGE_SUCCESS: > + if (is_thp) { > + nr_thp_succeeded++; > + nr_succeeded += nr_subpages; > + break; > + } > nr_succeeded++; > break; > default: > @@ -1493,19 +1521,27 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > * removed from migration page list and not > * retried in the next outer loop. > */ > + if (is_thp) { > + nr_thp_failed++; > + nr_failed += nr_subpages; > + break; > + } > nr_failed++; > break; > } > } > } > - nr_failed += retry; > + nr_failed += retry + thp_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); > - trace_mm_migrate_pages(nr_succeeded, nr_failed, mode, reason); > + 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); These references still cause build errors. > + trace_mm_migrate_pages(nr_succeeded, nr_failed, nr_thp_succeeded, > + nr_thp_failed, nr_thp_split, mode, reason); > > if (!swapwrite) > current->flags &= ~PF_SWAPWRITE; > diff --git a/mm/vmstat.c b/mm/vmstat.c > index 3fb23a21f6dd..09914a4bfee4 100644 > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -1234,6 +1234,9 @@ 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", > -- ~Randy
