From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
John Hubbard <jhubbard@nvidia.com>,
Jason Gunthorpe <jgg@nvidia.com>,
William Kucharski <william.kucharski@oracle.com>
Subject: [PATCH 15/75] mm/gup: Add try_get_folio() and try_grab_folio()
Date: Fri, 4 Feb 2022 19:57:52 +0000 [thread overview]
Message-ID: <20220204195852.1751729-16-willy@infradead.org> (raw)
In-Reply-To: <20220204195852.1751729-1-willy@infradead.org>
Convert try_get_compound_head() into try_get_folio() and convert
try_grab_compound_head() into try_grab_folio(). Add a temporary
try_grab_compound_head() wrapper around try_grab_folio() to let us
convert callers individually.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
---
mm/gup.c | 99 +++++++++++++++++++++++++--------------------------
mm/internal.h | 5 +++
2 files changed, 54 insertions(+), 50 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c
index a444b94c96fd..4f1669db92f5 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -47,75 +47,70 @@ static void put_page_refs(struct page *page, int refs)
}
/*
- * Return the compound head page with ref appropriately incremented,
+ * Return the folio with ref appropriately incremented,
* or NULL if that failed.
*/
-static inline struct page *try_get_compound_head(struct page *page, int refs)
+static inline struct folio *try_get_folio(struct page *page, int refs)
{
- struct page *head;
+ struct folio *folio;
retry:
- head = compound_head(page);
-
- if (WARN_ON_ONCE(page_ref_count(head) < 0))
+ folio = page_folio(page);
+ if (WARN_ON_ONCE(folio_ref_count(folio) < 0))
return NULL;
- if (unlikely(!page_cache_add_speculative(head, refs)))
+ if (unlikely(!folio_ref_try_add_rcu(folio, refs)))
return NULL;
/*
- * At this point we have a stable reference to the head page; but it
- * could be that between the compound_head() lookup and the refcount
- * increment, the compound page was split, in which case we'd end up
- * holding a reference on a page that has nothing to do with the page
+ * At this point we have a stable reference to the folio; but it
+ * could be that between calling page_folio() and the refcount
+ * increment, the folio was split, in which case we'd end up
+ * holding a reference on a folio that has nothing to do with the page
* we were given anymore.
- * So now that the head page is stable, recheck that the pages still
- * belong together.
+ * So now that the folio is stable, recheck that the page still
+ * belongs to this folio.
*/
- if (unlikely(compound_head(page) != head)) {
- put_page_refs(head, refs);
+ if (unlikely(page_folio(page) != folio)) {
+ folio_put_refs(folio, refs);
goto retry;
}
- return head;
+ return folio;
}
/**
- * try_grab_compound_head() - attempt to elevate a page's refcount, by a
- * flags-dependent amount.
- *
- * Even though the name includes "compound_head", this function is still
- * appropriate for callers that have a non-compound @page to get.
- *
+ * try_grab_folio() - Attempt to get or pin a folio.
* @page: pointer to page to be grabbed
- * @refs: the value to (effectively) add to the page's refcount
+ * @refs: the value to (effectively) add to the folio's refcount
* @flags: gup flags: these are the FOLL_* flag values.
*
* "grab" names in this file mean, "look at flags to decide whether to use
- * FOLL_PIN or FOLL_GET behavior, when incrementing the page's refcount.
+ * FOLL_PIN or FOLL_GET behavior, when incrementing the folio's refcount.
*
* Either FOLL_PIN or FOLL_GET (or neither) must be set, but not both at the
* same time. (That's true throughout the get_user_pages*() and
* pin_user_pages*() APIs.) Cases:
*
- * FOLL_GET: page's refcount will be incremented by @refs.
+ * FOLL_GET: folio's refcount will be incremented by @refs.
*
- * FOLL_PIN on compound pages: page's refcount will be incremented by
- * @refs, and page[1].compound_pincount will be incremented by @refs.
+ * FOLL_PIN on large folios: folio's refcount will be incremented by
+ * @refs, and its compound_pincount will be incremented by @refs.
*
- * FOLL_PIN on normal pages: page's refcount will be incremented by
+ * FOLL_PIN on single-page folios: folio's refcount will be incremented by
* @refs * GUP_PIN_COUNTING_BIAS.
*
- * Return: head page (with refcount appropriately incremented) for success, or
- * NULL upon failure. If neither FOLL_GET nor FOLL_PIN was set, that's
- * considered failure, and furthermore, a likely bug in the caller, so a warning
- * is also emitted.
+ * Return: The folio containing @page (with refcount appropriately
+ * incremented) for success, or NULL upon failure. If neither FOLL_GET
+ * nor FOLL_PIN was set, that's considered failure, and furthermore,
+ * a likely bug in the caller, so a warning is also emitted.
*/
-__maybe_unused struct page *try_grab_compound_head(struct page *page,
- int refs, unsigned int flags)
+struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags)
{
if (flags & FOLL_GET)
- return try_get_compound_head(page, refs);
+ return try_get_folio(page, refs);
else if (flags & FOLL_PIN) {
+ struct folio *folio;
+
/*
* 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
@@ -129,34 +124,38 @@ __maybe_unused struct page *try_grab_compound_head(struct page *page,
* CAUTION: Don't use compound_head() on the page before this
* point, the result won't be stable.
*/
- page = try_get_compound_head(page, refs);
- if (!page)
+ folio = try_get_folio(page, refs);
+ if (!folio)
return NULL;
/*
- * When pinning a compound page, use an exact count to
- * track it.
+ * When pinning a large folio, use an exact count to track it.
*
- * However, be sure to *also* increment the normal page
- * refcount field at least once, so that the page really
+ * However, be sure to *also* increment the normal folio
+ * refcount field at least once, so that the folio really
* is pinned. That's why the refcount from the earlier
- * try_get_compound_head() is left intact.
+ * try_get_folio() is left intact.
*/
- if (PageHead(page))
- atomic_add(refs, compound_pincount_ptr(page));
+ if (folio_test_large(folio))
+ atomic_add(refs, folio_pincount_ptr(folio));
else
- page_ref_add(page, refs * (GUP_PIN_COUNTING_BIAS - 1));
+ folio_ref_add(folio,
+ refs * (GUP_PIN_COUNTING_BIAS - 1));
+ node_stat_mod_folio(folio, NR_FOLL_PIN_ACQUIRED, refs);
- mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_ACQUIRED,
- refs);
-
- return page;
+ return folio;
}
WARN_ON_ONCE(1);
return NULL;
}
+struct page *try_grab_compound_head(struct page *page,
+ int refs, unsigned int flags)
+{
+ return &try_grab_folio(page, refs, flags)->page;
+}
+
static void put_compound_head(struct page *page, int refs, unsigned int flags)
{
VM_BUG_ON_PAGE(PageTail(page), page);
@@ -185,7 +184,7 @@ static void put_compound_head(struct page *page, int refs, unsigned int flags)
* @flags: gup flags: these are the FOLL_* flag values.
*
* Either FOLL_PIN or FOLL_GET (or neither) may be set, but not both at the same
- * time. Cases: please see the try_grab_compound_head() documentation, with
+ * time. Cases: please see the try_grab_folio() documentation, with
* "refs=1".
*
* Return: true for success, or if no action was required (if neither FOLL_PIN
diff --git a/mm/internal.h b/mm/internal.h
index d80300392a19..08a44802c80e 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -718,4 +718,9 @@ void vunmap_range_noflush(unsigned long start, unsigned long end);
int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
unsigned long addr, int page_nid, int *flags);
+/*
+ * mm/gup.c
+ */
+struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
+
#endif /* __MM_INTERNAL_H */
--
2.34.1
next prev parent reply other threads:[~2022-02-04 20:21 UTC|newest]
Thread overview: 115+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-04 19:57 [PATCH 00/75] MM folio patches for 5.18 Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 01/75] mm/gup: Increment the page refcount before the pincount Matthew Wilcox (Oracle)
2022-02-04 21:13 ` John Hubbard
2022-02-04 21:28 ` Matthew Wilcox
2022-02-07 7:45 ` Christoph Hellwig
2022-02-04 19:57 ` [PATCH 02/75] mm/gup: Remove for_each_compound_range() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 03/75] mm/gup: Remove for_each_compound_head() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 04/75] mm/gup: Change the calling convention for compound_range_next() Matthew Wilcox (Oracle)
2022-02-07 7:45 ` Christoph Hellwig
2022-02-04 19:57 ` [PATCH 05/75] mm/gup: Optimise compound_range_next() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 06/75] mm/gup: Change the calling convention for compound_next() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 07/75] mm/gup: Fix some contiguous memmap assumptions Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 08/75] mm/gup: Remove an assumption of a contiguous memmap Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 09/75] mm/gup: Handle page split race more efficiently Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 10/75] mm/gup: Remove hpage_pincount_add() Matthew Wilcox (Oracle)
2022-02-04 21:29 ` John Hubbard
2022-02-07 7:46 ` Christoph Hellwig
2022-02-04 19:57 ` [PATCH 11/75] mm/gup: Remove hpage_pincount_sub() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 12/75] mm: Make compound_pincount always available Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 13/75] mm: Add folio_pincount_ptr() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 14/75] mm: Turn page_maybe_dma_pinned() into folio_maybe_dma_pinned() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` Matthew Wilcox (Oracle) [this message]
2022-02-04 19:57 ` [PATCH 16/75] mm/gup: Convert try_grab_page() to use a folio Matthew Wilcox (Oracle)
2022-02-06 2:12 ` John Hubbard
2022-02-07 7:47 ` Christoph Hellwig
2022-02-04 19:57 ` [PATCH 17/75] mm: Remove page_cache_add_speculative() and page_cache_get_speculative() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 18/75] mm/gup: Add gup_put_folio() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 19/75] mm/hugetlb: Use try_grab_folio() instead of try_grab_compound_head() Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 20/75] mm/gup: Convert gup_pte_range() to use a folio Matthew Wilcox (Oracle)
2022-02-06 14:52 ` Mark Hemment
2022-02-11 20:20 ` Matthew Wilcox
2022-02-04 19:57 ` [PATCH 21/75] mm/gup: Convert gup_hugepte() " Matthew Wilcox (Oracle)
2022-02-04 19:57 ` [PATCH 22/75] mm/gup: Convert gup_huge_pmd() " Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 23/75] mm/gup: Convert gup_huge_pud() " Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 24/75] mm/gup: Convert gup_huge_pgd() " Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 25/75] mm/gup: Turn compound_next() into gup_folio_next() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 26/75] mm/gup: Turn compound_range_next() into gup_folio_range_next() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 27/75] mm: Turn isolate_lru_page() into folio_isolate_lru() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 28/75] mm/gup: Convert check_and_migrate_movable_pages() to use a folio Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 29/75] mm/workingset: Convert workingset_eviction() to take " Matthew Wilcox (Oracle)
2022-02-07 7:49 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 30/75] mm/memcg: Convert mem_cgroup_swapout() " Matthew Wilcox (Oracle)
2022-02-07 7:49 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 31/75] mm: Add lru_to_folio() Matthew Wilcox (Oracle)
2022-02-07 7:50 ` Christoph Hellwig
2022-02-11 20:24 ` Matthew Wilcox
2022-02-04 19:58 ` [PATCH 32/75] mm: Turn putback_lru_page() into folio_putback_lru() Matthew Wilcox (Oracle)
2022-02-07 7:50 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 33/75] mm/vmscan: Convert __remove_mapping() to take a folio Matthew Wilcox (Oracle)
2022-02-07 7:51 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 34/75] mm/vmscan: Turn page_check_dirty_writeback() into folio_check_dirty_writeback() Matthew Wilcox (Oracle)
2022-02-07 7:51 ` Christoph Hellwig
2022-02-12 1:49 ` Matthew Wilcox
2022-02-04 19:58 ` [PATCH 35/75] mm: Turn head_compound_mapcount() into folio_entire_mapcount() Matthew Wilcox (Oracle)
2022-02-07 7:52 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 36/75] mm: Add folio_mapcount() Matthew Wilcox (Oracle)
2022-02-07 7:53 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 37/75] mm: Add split_folio_to_list() Matthew Wilcox (Oracle)
2022-02-07 7:54 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 38/75] mm: Add folio_is_zone_device() and folio_is_device_private() Matthew Wilcox (Oracle)
2022-02-07 7:54 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 39/75] mm: Add folio_pgoff() Matthew Wilcox (Oracle)
2022-02-07 7:55 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 40/75] mm: Add pvmw_set_page() and pvmw_set_folio() Matthew Wilcox (Oracle)
2022-02-07 7:55 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 41/75] hexagon: Add pmd_pfn() Matthew Wilcox (Oracle)
2022-02-06 18:13 ` Mike Rapoport
2022-02-06 20:46 ` Matthew Wilcox
2022-02-06 21:33 ` Mike Rapoport
2022-02-06 22:05 ` Matthew Wilcox
2022-02-07 14:24 ` Mike Rapoport
2022-02-04 19:58 ` [PATCH 42/75] mm: Convert page_vma_mapped_walk to work on PFNs Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 43/75] mm/page_idle: Convert page_idle_clear_pte_refs() to use a folio Matthew Wilcox (Oracle)
2022-02-07 7:57 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 44/75] mm/rmap: Use a folio in page_mkclean_one() Matthew Wilcox (Oracle)
2022-02-07 7:57 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 45/75] mm/rmap: Turn page_referenced() into folio_referenced() Matthew Wilcox (Oracle)
2022-02-07 7:58 ` Christoph Hellwig
2022-02-04 19:58 ` [PATCH 46/75] mm/mlock: Turn clear_page_mlock() into folio_end_mlock() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 47/75] mm/mlock: Turn mlock_vma_page() into mlock_vma_folio() Matthew Wilcox (Oracle)
2022-02-07 10:46 ` Mike Rapoport
2022-02-04 19:58 ` [PATCH 48/75] mm/rmap: Turn page_mlock() into folio_mlock() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 49/75] mm/mlock: Turn munlock_vma_page() into munlock_vma_folio() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 50/75] mm/huge_memory: Convert __split_huge_pmd() to take a folio Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 51/75] mm/rmap: Convert try_to_unmap() " Matthew Wilcox (Oracle)
2022-02-09 14:24 ` Mauricio Faria de Oliveira
2022-02-09 14:29 ` Matthew Wilcox
2022-02-04 19:58 ` [PATCH 52/75] mm/rmap: Convert try_to_migrate() to folios Matthew Wilcox (Oracle)
2022-02-09 15:27 ` Zi Yan
2022-02-04 19:58 ` [PATCH 53/75] mm/rmap: Convert make_device_exclusive_range() to use folios Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 54/75] mm/migrate: Convert remove_migration_ptes() to folios Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 55/75] mm/damon: Convert damon_pa_mkold() to use a folio Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 56/75] mm/damon: Convert damon_pa_young() " Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 57/75] mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 58/75] mm: Turn page_anon_vma() into folio_anon_vma() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 59/75] mm/rmap: Convert rmap_walk() to take a folio Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 60/75] mm/rmap: Constify the rmap_walk_control argument Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 61/75] mm/vmscan: Free non-shmem folios without splitting them Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 62/75] mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 63/75] mm/vmscan: Account large folios correctly Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 64/75] mm/vmscan: Turn page_check_references() into folio_check_references() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 65/75] mm/vmscan: Convert pageout() to take a folio Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 66/75] mm: Turn can_split_huge_page() into can_split_folio() Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 67/75] mm/filemap: Allow large folios to be added to the page cache Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 68/75] mm: Fix READ_ONLY_THP warning Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 69/75] mm: Make large folios depend on THP Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 70/75] mm: Support arbitrary THP sizes Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 71/75] mm/readahead: Add large folio readahead Matthew Wilcox (Oracle)
2022-02-06 13:10 ` Mark Hemment
2022-02-04 19:58 ` [PATCH 72/75] mm/readahead: Align file mappings for non-DAX Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 73/75] mm/readahead: Switch to page_cache_ra_order Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 74/75] mm/filemap: Support VM_HUGEPAGE for file mappings Matthew Wilcox (Oracle)
2022-02-04 19:58 ` [PATCH 75/75] selftests/vm/transhuge-stress: Support file-backed PMD folios Matthew Wilcox (Oracle)
2022-02-13 22:31 ` [PATCH 00/75] MM folio patches for 5.18 John Hubbard
2022-02-14 4:33 ` Matthew Wilcox
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