| From 47467db20a4031d08692c2cb8faf012920a1eca2 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 4 May 2021 18:38:46 -0700 |
| Subject: mm/gup: return an error on migration failure |
| |
| From: Pavel Tatashin <pasha.tatashin@soleen.com> |
| |
| [ Upstream commit f0f4463837da17a89d965dcbe4e411629dbcf308 ] |
| |
| When migration failure occurs, we still pin pages, which means that we |
| may pin CMA movable pages which should never be the case. |
| |
| Instead return an error without pinning pages when migration failure |
| happens. |
| |
| No need to retry migrating, because migrate_pages() already retries 10 |
| times. |
| |
| Link: https://lkml.kernel.org/r/20210215161349.246722-4-pasha.tatashin@soleen.com |
| Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> |
| Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> |
| Cc: Dan Williams <dan.j.williams@intel.com> |
| Cc: David Hildenbrand <david@redhat.com> |
| Cc: David Rientjes <rientjes@google.com> |
| Cc: Ingo Molnar <mingo@redhat.com> |
| Cc: Ira Weiny <ira.weiny@intel.com> |
| Cc: James Morris <jmorris@namei.org> |
| Cc: Jason Gunthorpe <jgg@ziepe.ca> |
| Cc: John Hubbard <jhubbard@nvidia.com> |
| Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> |
| Cc: Matthew Wilcox <willy@infradead.org> |
| Cc: Mel Gorman <mgorman@suse.de> |
| Cc: Michal Hocko <mhocko@kernel.org> |
| Cc: Michal Hocko <mhocko@suse.com> |
| Cc: Mike Kravetz <mike.kravetz@oracle.com> |
| Cc: Oscar Salvador <osalvador@suse.de> |
| Cc: Peter Zijlstra <peterz@infradead.org> |
| Cc: Sasha Levin <sashal@kernel.org> |
| Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> |
| Cc: Tyler Hicks <tyhicks@linux.microsoft.com> |
| Cc: Vlastimil Babka <vbabka@suse.cz> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| mm/gup.c | 17 +++++++---------- |
| 1 file changed, 7 insertions(+), 10 deletions(-) |
| |
| diff --git a/mm/gup.c b/mm/gup.c |
| index e10807c4c46b..0fa8d88eb7ba 100644 |
| --- a/mm/gup.c |
| +++ b/mm/gup.c |
| @@ -1563,7 +1563,6 @@ static long check_and_migrate_cma_pages(struct mm_struct *mm, |
| { |
| unsigned long i; |
| bool drain_allow = true; |
| - bool migrate_allow = true; |
| LIST_HEAD(cma_page_list); |
| long ret = nr_pages; |
| struct page *prev_head, *head; |
| @@ -1614,17 +1613,15 @@ check_again: |
| for (i = 0; i < nr_pages; i++) |
| put_page(pages[i]); |
| |
| - if (migrate_pages(&cma_page_list, alloc_migration_target, NULL, |
| - (unsigned long)&mtc, MIGRATE_SYNC, MR_CONTIG_RANGE)) { |
| - /* |
| - * some of the pages failed migration. Do get_user_pages |
| - * without migration. |
| - */ |
| - migrate_allow = false; |
| - |
| + ret = migrate_pages(&cma_page_list, alloc_migration_target, |
| + NULL, (unsigned long)&mtc, MIGRATE_SYNC, |
| + MR_CONTIG_RANGE); |
| + if (ret) { |
| if (!list_empty(&cma_page_list)) |
| putback_movable_pages(&cma_page_list); |
| + return ret > 0 ? -ENOMEM : ret; |
| } |
| + |
| /* |
| * We did migrate all the pages, Try to get the page references |
| * again migrating any new CMA pages which we failed to isolate |
| @@ -1634,7 +1631,7 @@ check_again: |
| pages, vmas, NULL, |
| gup_flags); |
| |
| - if ((ret > 0) && migrate_allow) { |
| + if (ret > 0) { |
| nr_pages = ret; |
| drain_allow = true; |
| goto check_again; |
| -- |
| 2.30.2 |
| |