From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Hugh Dickins <hughd@google.com>,
William Kucharski <william.kucharski@oracle.com>,
Jani Nikula <jani.nikula@linux.intel.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Chris Wilson <chris@chris-wilson.co.uk>,
Matthew Auld <matthew.auld@intel.com>,
Huang Ying <ying.huang@intel.com>,
intel-gfx@lists.freedesktop.org, cgroups@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/8] mm: Factor find_get_incore_page out of mincore_page
Date: Thu, 10 Sep 2020 19:33:11 +0100 [thread overview]
Message-ID: <20200910183318.20139-2-willy@infradead.org> (raw)
In-Reply-To: <20200910183318.20139-1-willy@infradead.org>
Provide this functionality from the swap cache. It's useful for
more than just mincore().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
include/linux/swap.h | 7 +++++++
mm/mincore.c | 28 ++--------------------------
mm/swap_state.c | 32 ++++++++++++++++++++++++++++++++
3 files changed, 41 insertions(+), 26 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 661046994db4..df87de38dca5 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -427,6 +427,7 @@ extern void free_pages_and_swap_cache(struct page **, int);
extern struct page *lookup_swap_cache(swp_entry_t entry,
struct vm_area_struct *vma,
unsigned long addr);
+struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index);
extern struct page *read_swap_cache_async(swp_entry_t, gfp_t,
struct vm_area_struct *vma, unsigned long addr,
bool do_poll);
@@ -569,6 +570,12 @@ static inline struct page *lookup_swap_cache(swp_entry_t swp,
return NULL;
}
+static inline
+struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
+{
+ return find_get_page(mapping, index);
+}
+
static inline int add_to_swap(struct page *page)
{
return 0;
diff --git a/mm/mincore.c b/mm/mincore.c
index 453ff112470f..02db1a834021 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -48,7 +48,7 @@ static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr,
* and is up to date; i.e. that no page-in operation would be required
* at this time if an application were to map and access this page.
*/
-static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff)
+static unsigned char mincore_page(struct address_space *mapping, pgoff_t index)
{
unsigned char present = 0;
struct page *page;
@@ -59,31 +59,7 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff)
* any other file mapping (ie. marked !present and faulted in with
* tmpfs's .fault). So swapped out tmpfs mappings are tested here.
*/
-#ifdef CONFIG_SWAP
- if (shmem_mapping(mapping)) {
- page = find_get_entry(mapping, pgoff);
- /*
- * shmem/tmpfs may return swap: account for swapcache
- * page too.
- */
- if (xa_is_value(page)) {
- swp_entry_t swp = radix_to_swp_entry(page);
- struct swap_info_struct *si;
-
- /* Prevent swap device to being swapoff under us */
- si = get_swap_device(swp);
- if (si) {
- page = find_get_page(swap_address_space(swp),
- swp_offset(swp));
- put_swap_device(si);
- } else
- page = NULL;
- }
- } else
- page = find_get_page(mapping, pgoff);
-#else
- page = find_get_page(mapping, pgoff);
-#endif
+ page = find_get_incore_page(mapping, index);
if (page) {
present = PageUptodate(page);
put_page(page);
diff --git a/mm/swap_state.c b/mm/swap_state.c
index c16eebb81d8b..c79e2242dd04 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -21,6 +21,7 @@
#include <linux/vmalloc.h>
#include <linux/swap_slots.h>
#include <linux/huge_mm.h>
+#include <linux/shmem_fs.h>
#include "internal.h"
/*
@@ -414,6 +415,37 @@ struct page *lookup_swap_cache(swp_entry_t entry, struct vm_area_struct *vma,
return page;
}
+/**
+ * find_get_incore_page - Find and get a page from the page or swap caches.
+ * @mapping: The address_space to search.
+ * @index: The page cache index.
+ *
+ * This differs from find_get_page() in that it will also look for the
+ * page in the swap cache.
+ *
+ * Return: The found page or %NULL.
+ */
+struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
+{
+ swp_entry_t swp;
+ struct swap_info_struct *si;
+ struct page *page = find_get_entry(mapping, index);
+
+ if (!xa_is_value(page))
+ return page;
+ if (!shmem_mapping(mapping))
+ return NULL;
+
+ swp = radix_to_swp_entry(page);
+ /* Prevent swapoff from happening to us */
+ si = get_swap_device(swp);
+ if (!si)
+ return NULL;
+ page = find_get_page(swap_address_space(swp), swp_offset(swp));
+ put_swap_device(si);
+ return page;
+}
+
struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
struct vm_area_struct *vma, unsigned long addr,
bool *new_page_allocated)
--
2.28.0
next prev parent reply other threads:[~2020-09-10 18:33 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 18:33 [PATCH v2 0/8] Return head pages from find_*_entry Matthew Wilcox (Oracle)
2020-09-10 18:33 ` Matthew Wilcox (Oracle) [this message]
2020-09-10 18:33 ` [PATCH v2 2/8] mm: Use find_get_incore_page in memcontrol Matthew Wilcox (Oracle)
2020-09-10 18:33 ` [PATCH v2 3/8] mm: Optimise madvise WILLNEED Matthew Wilcox (Oracle)
2020-09-14 16:17 ` Qian Cai
2020-09-14 16:47 ` Qian Cai
2020-09-14 16:50 ` Matthew Wilcox
2020-09-14 19:44 ` Qian Cai
2020-09-10 18:33 ` [PATCH v2 4/8] proc: Optimise smaps for shmem entries Matthew Wilcox (Oracle)
2020-09-10 18:33 ` [PATCH v2 5/8] i915: Use find_lock_page instead of find_lock_entry Matthew Wilcox (Oracle)
2020-09-10 18:33 ` [PATCH v2 6/8] mm: Convert find_get_entry to return the head page Matthew Wilcox (Oracle)
2020-09-14 8:55 ` [mm] 2037ab69a5: BUG:KASAN:null-ptr-deref_in_t kernel test robot
2020-09-14 11:27 ` Matthew Wilcox
2020-09-10 18:33 ` [PATCH v2 7/8] mm/shmem: Return head page from find_lock_entry Matthew Wilcox (Oracle)
2020-09-12 3:20 ` Matthew Wilcox
2020-09-10 18:33 ` [PATCH v2 8/8] mm: Add find_lock_head Matthew Wilcox (Oracle)
2020-09-15 8:10 ` [PATCH v2 0/8] Return head pages from find_*_entry Hugh Dickins
2020-09-15 12:53 ` Naresh Kamboju
2020-09-15 13:08 ` Matthew Wilcox
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