mm: migrate: Do not retry 10 times for the subpages of fail-to-migrate THP
Subsystems (2)
PATCH 1/1 mm: migrate: Do not retry 10 times for the subpages of fail-to-migrate THP
If THP is failed to migrate due to -ENOSYS or -ENOMEM case, the THP will be split, and the subpages of fail-to-migrate THP will be tried to migrate again, so we should not account the retry counter in the second loop, since we already accounted 'nr_thp_failed' in the first loop.
Moreover we also do not need retry 10 times for -EAGAIN case for the subpages of fail-to-migrate THP in the second loop, since we already regarded the THP as migration failure, and save some migration time (for the worst case, will try 512 * 10 times) according to previous discussion [1].
[1] https://lore.kernel.org/linux-mm/[email protected]/
---
Note, this patch is based on the patch set [1] from Huang Ying.
[1] https://lore.kernel.org/linux-mm/[email protected]/
--- mm/migrate.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
mm/migrate.c +2 -3
@@ -1507,7 +1507,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,case -EAGAIN :if (is_thp) thp_retry++; -else +else if (!no_subpage_counting) retry++; nr_retry_pages += nr_subpages;break ;
@@ -1533,8 +1533,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, } } } -if (!no_subpage_counting) - nr_failed += retry; + nr_failed += retry; nr_thp_failed += thp_retry; nr_failed_pages += nr_retry_pages;/*
Signature · 1 line
1.8.3.1
Zi Yan
reviewerQuoted 45 lines · Baolin Wang
If THP is failed to migrate due to
-ENOSYSor-ENOMEMcase, the THP will be split, and the subpages of fail-to-migrate THP will be tried to migrate again, so we should not account the retry counter in the second loop, since we already accounted 'nr_thp_failed' in the first loop.Moreover we also do not need retry 10 times for
-EAGAINcase for the subpages of fail-to-migrate THP in the second loop, since we already regarded the THP as migration failure, and save some migration time (for the worst case, will try 512 * 10 times) according to previous discussion [1].[1] https://lore.kernel.org/linux-mm/[email protected]/
Signed-off-by Baolin Wang <[email protected]>---
Note, this patch is based on the patch set [1] from Huang Ying.
[1] https://lore.kernel.org/linux-mm/[email protected]/--- mm/migrate.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)mm/migrate.c +2
-3@@ -1507,7 +1507,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,case -EAGAIN :if (is_thp) thp_retry++; -else +else if (!no_subpage_counting) retry++; nr_retry_pages += nr_subpages;break ;@@ -1533,8 +1533,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, } } } -if (!no_subpage_counting) - nr_failed += retry; + nr_failed += retry; nr_thp_failed += thp_retry; nr_failed_pages += nr_retry_pages;/* Signature · 1 line
1.8.3.1
LGTM. Thanks. Reviewed-by: Zi Yan <[email protected]>
--
Best Regards,
Yan, Zi
Hi, Baolin,
Quoted 5 lines · Baolin Wang
If THP is failed to migrate due to
-ENOSYSor-ENOMEMcase, the THP will be split, and the subpages of fail-to-migrate THP will be tried to migrate again, so we should not account the retry counter in the second loop, since we already accounted 'nr_thp_failed' in the first loop.
Quoted 8 lines
Moreover we also do not need retry 10 times for
-EAGAINcase for the subpages of fail-to-migrate THP in the second loop, since we already regarded the THP as migration failure, and save some migration time (for the worst case, will try 512 * 10 times) according to previous discussion [1].[1] https://lore.kernel.org/linux-mm/[email protected]/
Signed-off-by Baolin Wang <[email protected]>
I have tested this patch, and it works as expected.
Quoted 3 lines
---
Note, this patch is based on the patch set [1] from Huang Ying.
[1] https://lore.kernel.org/linux-mm/[email protected]/
Please this patch is based on my patchset that hasn't been merged. I can add it as the last patch of my migrate_pages failure path fixing patchset if you don't object.
Best Regards,
Huang, Ying
Quoted 27 lines
--- mm/migrate.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)mm/migrate.c +2
-3@@ -1507,7 +1507,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,case -EAGAIN :if (is_thp) thp_retry++; -else +else if (!no_subpage_counting) retry++; nr_retry_pages += nr_subpages;break ;@@ -1533,8 +1533,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, } } } -if (!no_subpage_counting) - nr_failed += retry; + nr_failed += retry; nr_thp_failed += thp_retry; nr_failed_pages += nr_retry_pages;/*
Quoted 14 lines · Ying
Hi, Baolin,
Quoted 10 lines · Baolin Wang
If THP is failed to migrate due to
-ENOSYSor-ENOMEMcase, the THP will be split, and the subpages of fail-to-migrate THP will be tried to migrate again, so we should not account the retry counter in the second loop, since we already accounted 'nr_thp_failed' in the first loop.Moreover we also do not need retry 10 times for
-EAGAINcase for the subpages of fail-to-migrate THP in the second loop, since we already regarded the THP as migration failure, and save some migration time (for the worst case, will try 512 * 10 times) according to previous discussion [1].
Quoted 7 lines
Quoted 3 lines
[1] https://lore.kernel.org/linux-mm/[email protected]/
Signed-off-by Baolin Wang <[email protected]>I have tested this patch, and it works as expected.
Tested-by "Huang, Ying" <[email protected]>
Thanks.
Quoted 8 lines
Quoted 4 lines
---
Note, this patch is based on the patch set [1] from Huang Ying.
[1] https://lore.kernel.org/linux-mm/[email protected]/Please this patch is based on my patchset that hasn't been merged. I can add it as the last patch of my
migrate_pagesfailure path fixing patchset if you don't object.
Sure, please fold it into your series. Thanks for helping.