| Message ID | 20220105214756.91065-3-zi.yan@sent.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Use pageblock_order for cma and alloc_contig_range alignment. | expand |
On 05.01.22 22:47, Zi Yan wrote: > From: Zi Yan <ziy@nvidia.com> > > In isolate_migratepages_block(), a !PageLRU tail page can be encountered > when the page is larger than a pageblock. Use compound head page for the > checks inside and skip the entire compound page when isolation succeeds. > This will currently never happen, due to the way we always isolate MAX_ORDER -1 ranges, correct? Better note that in the patch description, because currently it reads like it's an actual fix "can be encountered". > Signed-off-by: Zi Yan <ziy@nvidia.com> > --- > mm/compaction.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index b4e94cda3019..ad9053fbbe06 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -979,19 +979,23 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, > * Skip any other type of page > */ > if (!PageLRU(page)) { > + struct page *head = compound_head(page); > /* > * __PageMovable can return false positive so we need > * to verify it under page_lock. > */ > - if (unlikely(__PageMovable(page)) && > - !PageIsolated(page)) { > + if (unlikely(__PageMovable(head)) && > + !PageIsolated(head)) { > if (locked) { > unlock_page_lruvec_irqrestore(locked, flags); > locked = NULL; > } > > - if (!isolate_movable_page(page, isolate_mode)) > + if (!isolate_movable_page(head, isolate_mode)) { > + low_pfn += (1 << compound_order(head)) - 1 - (page - head); > + page = head; > goto isolate_success; > + } > } > > goto isolate_fail;
On 12 Jan 2022, at 6:01, David Hildenbrand wrote: > On 05.01.22 22:47, Zi Yan wrote: >> From: Zi Yan <ziy@nvidia.com> >> >> In isolate_migratepages_block(), a !PageLRU tail page can be encountered >> when the page is larger than a pageblock. Use compound head page for the >> checks inside and skip the entire compound page when isolation succeeds. >> > > This will currently never happen, due to the way we always isolate > MAX_ORDER -1 ranges, correct? You are right. > > Better note that in the patch description, because currently it reads > like it's an actual fix "can be encountered". > Will do. This is a preparation patch for the upcoming commits. >> Signed-off-by: Zi Yan <ziy@nvidia.com> >> --- >> mm/compaction.c | 10 +++++++--- >> 1 file changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/mm/compaction.c b/mm/compaction.c >> index b4e94cda3019..ad9053fbbe06 100644 >> --- a/mm/compaction.c >> +++ b/mm/compaction.c >> @@ -979,19 +979,23 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, >> * Skip any other type of page >> */ >> if (!PageLRU(page)) { >> + struct page *head = compound_head(page); >> /* >> * __PageMovable can return false positive so we need >> * to verify it under page_lock. >> */ >> - if (unlikely(__PageMovable(page)) && >> - !PageIsolated(page)) { >> + if (unlikely(__PageMovable(head)) && >> + !PageIsolated(head)) { >> if (locked) { >> unlock_page_lruvec_irqrestore(locked, flags); >> locked = NULL; >> } >> >> - if (!isolate_movable_page(page, isolate_mode)) >> + if (!isolate_movable_page(head, isolate_mode)) { >> + low_pfn += (1 << compound_order(head)) - 1 - (page - head); >> + page = head; >> goto isolate_success; >> + } >> } >> >> goto isolate_fail; > > > -- > Thanks, > > David / dhildenb -- Best Regards, Yan, Zi
On 13 Jan 2022, at 9:57, Zi Yan wrote: > On 12 Jan 2022, at 6:01, David Hildenbrand wrote: > >> On 05.01.22 22:47, Zi Yan wrote: >>> From: Zi Yan <ziy@nvidia.com> >>> >>> In isolate_migratepages_block(), a !PageLRU tail page can be encountered >>> when the page is larger than a pageblock. Use compound head page for the >>> checks inside and skip the entire compound page when isolation succeeds. >>> >> >> This will currently never happen, due to the way we always isolate >> MAX_ORDER -1 ranges, correct? > > You are right. > >> >> Better note that in the patch description, because currently it reads >> like it's an actual fix "can be encountered". >> > > Will do. This is a preparation patch for the upcoming commits. I will drop this one too. Like you mentioned in [1], there are no non-lru migratable compound pages. This is only used by my local test code. [1] https://lore.kernel.org/linux-mm/970ca2a4-416d-7e8f-37c7-510c5b050f4b@redhat.com/ > >>> Signed-off-by: Zi Yan <ziy@nvidia.com> >>> --- >>> mm/compaction.c | 10 +++++++--- >>> 1 file changed, 7 insertions(+), 3 deletions(-) >>> >>> diff --git a/mm/compaction.c b/mm/compaction.c >>> index b4e94cda3019..ad9053fbbe06 100644 >>> --- a/mm/compaction.c >>> +++ b/mm/compaction.c >>> @@ -979,19 +979,23 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, >>> * Skip any other type of page >>> */ >>> if (!PageLRU(page)) { >>> + struct page *head = compound_head(page); >>> /* >>> * __PageMovable can return false positive so we need >>> * to verify it under page_lock. >>> */ >>> - if (unlikely(__PageMovable(page)) && >>> - !PageIsolated(page)) { >>> + if (unlikely(__PageMovable(head)) && >>> + !PageIsolated(head)) { >>> if (locked) { >>> unlock_page_lruvec_irqrestore(locked, flags); >>> locked = NULL; >>> } >>> >>> - if (!isolate_movable_page(page, isolate_mode)) >>> + if (!isolate_movable_page(head, isolate_mode)) { >>> + low_pfn += (1 << compound_order(head)) - 1 - (page - head); >>> + page = head; >>> goto isolate_success; >>> + } >>> } >>> >>> goto isolate_fail; >> >> >> -- >> Thanks, >> >> David / dhildenb > > > -- > Best Regards, > Yan, Zi -- Best Regards, Yan, Zi
diff --git a/mm/compaction.c b/mm/compaction.c index b4e94cda3019..ad9053fbbe06 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -979,19 +979,23 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, * Skip any other type of page */ if (!PageLRU(page)) { + struct page *head = compound_head(page); /* * __PageMovable can return false positive so we need * to verify it under page_lock. */ - if (unlikely(__PageMovable(page)) && - !PageIsolated(page)) { + if (unlikely(__PageMovable(head)) && + !PageIsolated(head)) { if (locked) { unlock_page_lruvec_irqrestore(locked, flags); locked = NULL; } - if (!isolate_movable_page(page, isolate_mode)) + if (!isolate_movable_page(head, isolate_mode)) { + low_pfn += (1 << compound_order(head)) - 1 - (page - head); + page = head; goto isolate_success; + } } goto isolate_fail;