On 07/09/2020 11:12 PM, Zi Yan wrote: > On 9 Jul 2020, at 12:39, Randy Dunlap wrote: > >> On 7/9/20 9:34 AM, Zi Yan wrote: >>> On 9 Jul 2020, at 11:34, Randy Dunlap wrote: >>> >>>> 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", >>>>> >>> Which arch are you building? I did not see any error >>> after applying this patch on mmotm (reverting the existing ones) >>> and compiling them on x86_64. I used make x86_64_defconfig and >>> unselected COMPACTION and MIGRATION. >> Hi, >> >> I am trying to build x86_64. >> Maybe I am just having trouble replacing the patch file. >> Like I tried to say, I would prefer to see an incremental patch >> to fix mmotm or linux-next. > I agree. The patch does not apply to mmotm. Can you try the incremental > patch below? It should apply to mmotm. > > > Hi Andrew and Anshuman, > > Should Anshuman resend the incremental patch or Andrew can fold it along > with the two patches in mmotm into one? V3 patch and fixes on it were reverted from linux-next yesterday. The change for V4 patch was not small, hence just went with a fresh one instead. Please do let me know if this is still not settled and needs further action. https://lore.kernel.org/linux-next/20200709182150.7b49e5e8@xxxxxxxxxxxxxxxx/T/#u
