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mm/gup: migrate pinned pages out of movable zone

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We should not pin pages in ZONE_MOVABLE.  Currently, we do not pin only
movable CMA pages.  Generalize the function that migrates CMA pages to
migrate all movable pages.  Use is_pinnable_page() to check which pages
need to be migrated

Link: https://lkml.kernel.org/r/20210215161349.246722-10-pasha.tatashin@soleen.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: John Hubbard <jhubbard@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@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
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>
This commit is contained in:
Pavel Tatashin 2021-05-04 18:39:08 -07:00 committed by Linus Torvalds
parent 9afaf30f7a
commit d1e153fea2
4 changed files with 44 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/migrate.h
View File

@ -27,6 +27,7 @@ enum migrate_reason {
MR_MEMPOLICY_MBIND,
MR_NUMA_MISPLACED,
MR_CONTIG_RANGE,
MR_LONGTERM_PIN,
MR_TYPES
};

9
include/linux/mmzone.h
View File

@ -407,8 +407,13 @@ enum zone_type {
* to increase the number of THP/huge pages. Notable special cases are:
*
* 1. Pinned pages: (long-term) pinning of movable pages might
* essentially turn such pages unmovable. Memory offlining might
* retry a long time.
* essentially turn such pages unmovable. Therefore, we do not allow
* pinning long-term pages in ZONE_MOVABLE. When pages are pinned and
* faulted, they come from the right zone right away. However, it is
* still possible that address space already has pages in
* ZONE_MOVABLE at the time when pages are pinned (i.e. user has
* touches that memory before pinning). In such case we migrate them
* to a different zone. When migration fails - pinning fails.
* 2. memblock allocations: kernelcore/movablecore setups might create
* situations where ZONE_MOVABLE contains unmovable allocations
* after boot. Memory offlining and allocations fail early.

3
include/trace/events/migrate.h
View File

@ -20,7 +20,8 @@
EM( MR_SYSCALL, "syscall_or_cpuset") \
EM( MR_MEMPOLICY_MBIND, "mempolicy_mbind") \
EM( MR_NUMA_MISPLACED, "numa_misplaced") \
EMe(MR_CONTIG_RANGE, "contig_range")
EM( MR_CONTIG_RANGE, "contig_range") \
EMe(MR_LONGTERM_PIN, "longterm_pin")
/*
* First define the enums in the above macros to be exported to userspace

47
mm/gup.c
View File

@ -87,11 +87,12 @@ __maybe_unused struct page *try_grab_compound_head(struct page *page,
int orig_refs = refs;
/*
* Can't do FOLL_LONGTERM + FOLL_PIN with CMA in the gup fast
* path, so fail and let the caller fall back to the slow path.
* Can't do FOLL_LONGTERM + FOLL_PIN gup fast path if not in a
* right zone, so fail and let the caller fall back to the slow
* path.
*/
if (unlikely(flags & FOLL_LONGTERM) &&
is_migrate_cma_page(page))
if (unlikely((flags & FOLL_LONGTERM) &&
!is_pinnable_page(page)))
return NULL;
/*
@ -1600,8 +1601,8 @@ struct page *get_dump_page(unsigned long addr)
}
#endif /* CONFIG_ELF_CORE */
#ifdef CONFIG_CMA
static long check_and_migrate_cma_pages(struct mm_struct *mm,
#ifdef CONFIG_MIGRATION
static long check_and_migrate_movable_pages(struct mm_struct *mm,
unsigned long start,
unsigned long nr_pages,
struct page **pages,
@ -1610,7 +1611,7 @@ static long check_and_migrate_cma_pages(struct mm_struct *mm,
{
unsigned long i, isolation_error_count;
bool drain_allow;
LIST_HEAD(cma_page_list);
LIST_HEAD(movable_page_list);
long ret = nr_pages;
struct page *prev_head, *head;
struct migration_target_control mtc = {
@ -1628,13 +1629,12 @@ check_again:
continue;
prev_head = head;
/*
* If we get a page from the CMA zone, since we are going to
* be pinning these entries, we might as well move them out
* of the CMA zone if possible.
* If we get a movable page, since we are going to be pinning
* these entries, try to move them out if possible.
*/
if (is_migrate_cma_page(head)) {
if (!is_pinnable_page(head)) {
if (PageHuge(head)) {
if (!isolate_huge_page(head, &cma_page_list))
if (!isolate_huge_page(head, &movable_page_list))
isolation_error_count++;
} else {
if (!PageLRU(head) && drain_allow) {
@ -1646,7 +1646,7 @@ check_again:
isolation_error_count++;
continue;
}
list_add_tail(&head->lru, &cma_page_list);
list_add_tail(&head->lru, &movable_page_list);
mod_node_page_state(page_pgdat(head),
NR_ISOLATED_ANON +
page_is_file_lru(head),
@ -1659,10 +1659,10 @@ check_again:
* If list is empty, and no isolation errors, means that all pages are
* in the correct zone.
*/
if (list_empty(&cma_page_list) && !isolation_error_count)
if (list_empty(&movable_page_list) && !isolation_error_count)
return ret;
if (!list_empty(&cma_page_list)) {
if (!list_empty(&movable_page_list)) {
/*
* drop the above get_user_pages reference.
*/
@ -1672,12 +1672,12 @@ check_again:
for (i = 0; i < nr_pages; i++)
put_page(pages[i]);
ret = migrate_pages(&cma_page_list, alloc_migration_target,
ret = migrate_pages(&movable_page_list, alloc_migration_target,
NULL, (unsigned long)&mtc, MIGRATE_SYNC,
MR_CONTIG_RANGE);
MR_LONGTERM_PIN);
if (ret) {
if (!list_empty(&cma_page_list))
putback_movable_pages(&cma_page_list);
if (!list_empty(&movable_page_list))
putback_movable_pages(&movable_page_list);
return ret > 0 ? -ENOMEM : ret;
}
@ -1696,7 +1696,7 @@ check_again:
goto check_again;
}
#else
static long check_and_migrate_cma_pages(struct mm_struct *mm,
static long check_and_migrate_movable_pages(struct mm_struct *mm,
unsigned long start,
unsigned long nr_pages,
struct page **pages,
@ -1705,7 +1705,7 @@ static long check_and_migrate_cma_pages(struct mm_struct *mm,
{
return nr_pages;
}
#endif /* CONFIG_CMA */
#endif /* CONFIG_MIGRATION */
/*
* __gup_longterm_locked() is a wrapper for __get_user_pages_locked which
@ -1729,8 +1729,9 @@ static long __gup_longterm_locked(struct mm_struct *mm,
if (gup_flags & FOLL_LONGTERM) {
if (rc > 0)
rc = check_and_migrate_cma_pages(mm, start, rc, pages,
vmas, gup_flags);
rc = check_and_migrate_movable_pages(mm, start, rc,
pages, vmas,
gup_flags);
memalloc_pin_restore(flags);
}
return rc;