The patch titled
proc: export more page flags in /proc/kpageflags
has been added to the -mm tree. Its filename is
proc-export-more-page-flags-in-proc-kpageflags.patch
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------------------------------------------------------
Subject: proc: export more page flags in /proc/kpageflags
From: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Export all page flags faithfully in /proc/kpageflags.
11. KPF_MMAP (pseudo flag) memory mapped page
12. KPF_ANON (pseudo flag) memory mapped page (anonymous)
13. KPF_SWAPCACHE page is in swap cache
14. KPF_SWAPBACKED page is swap/RAM backed
15. KPF_COMPOUND_HEAD (*)
16. KPF_COMPOUND_TAIL (*)
17. KPF_HUGE hugeTLB pages
18. KPF_UNEVICTABLE page is in the unevictable LRU list
19. KPF_HWPOISON(TBD) hardware detected corruption
20. KPF_NOPAGE (pseudo flag) no page frame at the address
32-39. more obscure flags for kernel developers
(*) For compound pages, exporting _both_ head/tail info enables
users to tell where a compound page starts/ends, and its order.
The acompanied page-types tool will handle the details like decoupling
overloaded flags and hiding obscure flags to normal users.
Thanks to KOSAKI and Andi for their valuable recommendations!
Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/page.c | 148 +++++++++++++++++++++++++++++++++++++----------
1 file changed, 118 insertions(+), 30 deletions(-)
diff -puN fs/proc/page.c~proc-export-more-page-flags-in-proc-kpageflags fs/proc/page.c
--- a/fs/proc/page.c~proc-export-more-page-flags-in-proc-kpageflags
+++ a/fs/proc/page.c
@@ -71,19 +71,124 @@ static const struct file_operations proc
/* These macros are used to decouple internal flags from exported ones */
-#define KPF_LOCKED 0
-#define KPF_ERROR 1
-#define KPF_REFERENCED 2
-#define KPF_UPTODATE 3
-#define KPF_DIRTY 4
-#define KPF_LRU 5
-#define KPF_ACTIVE 6
-#define KPF_SLAB 7
-#define KPF_WRITEBACK 8
-#define KPF_RECLAIM 9
-#define KPF_BUDDY 10
+#define KPF_LOCKED 0
+#define KPF_ERROR 1
+#define KPF_REFERENCED 2
+#define KPF_UPTODATE 3
+#define KPF_DIRTY 4
+#define KPF_LRU 5
+#define KPF_ACTIVE 6
+#define KPF_SLAB 7
+#define KPF_WRITEBACK 8
+#define KPF_RECLAIM 9
+#define KPF_BUDDY 10
+
+/* 11-20: new additions in 2.6.31 */
+#define KPF_MMAP 11
+#define KPF_ANON 12
+#define KPF_SWAPCACHE 13
+#define KPF_SWAPBACKED 14
+#define KPF_COMPOUND_HEAD 15
+#define KPF_COMPOUND_TAIL 16
+#define KPF_HUGE 17
+#define KPF_UNEVICTABLE 18
+#define KPF_NOPAGE 20
+
+/* kernel hacking assistances
+ * WARNING: subject to change, never rely on them!
+ */
+#define KPF_RESERVED 32
+#define KPF_MLOCKED 33
+#define KPF_MAPPEDTODISK 34
+#define KPF_PRIVATE 35
+#define KPF_PRIVATE_2 36
+#define KPF_OWNER_PRIVATE 37
+#define KPF_ARCH 38
+#define KPF_UNCACHED 39
-#define kpf_copy_bit(flags, dstpos, srcpos) (((flags >> srcpos) & 1) << dstpos)
+static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
+{
+ return ((kflags >> kbit) & 1) << ubit;
+}
+
+static u64 get_uflags(struct page *page)
+{
+ u64 k;
+ u64 u;
+
+ /*
+ * pseudo flag: KPF_NOPAGE
+ * it differentiates a memory hole from a page with no flags
+ */
+ if (!page)
+ return 1 << KPF_NOPAGE;
+
+ k = page->flags;
+ u = 0;
+
+ /*
+ * pseudo flags for the well known (anonymous) memory mapped pages
+ *
+ * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
+ * simple test in page_mapped() is not enough.
+ */
+ if (!PageSlab(page) && page_mapped(page))
+ u |= 1 << KPF_MMAP;
+ if (PageAnon(page))
+ u |= 1 << KPF_ANON;
+
+ /*
+ * compound pages: export both head/tail info
+ * they together define a compound page's start/end pos and order
+ */
+ if (PageHead(page))
+ u |= 1 << KPF_COMPOUND_HEAD;
+ if (PageTail(page))
+ u |= 1 << KPF_COMPOUND_TAIL;
+ if (PageHuge(page))
+ u |= 1 << KPF_HUGE;
+
+ u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked);
+
+ /*
+ * Caveats on high order pages:
+ * PG_buddy will only be set on the head page; SLUB/SLQB do the same
+ * for PG_slab; SLOB won't set PG_slab at all on compound pages.
+ */
+ u |= kpf_copy_bit(k, KPF_SLAB, PG_slab);
+ u |= kpf_copy_bit(k, KPF_BUDDY, PG_buddy);
+
+ u |= kpf_copy_bit(k, KPF_ERROR, PG_error);
+ u |= kpf_copy_bit(k, KPF_DIRTY, PG_dirty);
+ u |= kpf_copy_bit(k, KPF_UPTODATE, PG_uptodate);
+ u |= kpf_copy_bit(k, KPF_WRITEBACK, PG_writeback);
+
+ u |= kpf_copy_bit(k, KPF_LRU, PG_lru);
+ u |= kpf_copy_bit(k, KPF_REFERENCED, PG_referenced);
+ u |= kpf_copy_bit(k, KPF_ACTIVE, PG_active);
+ u |= kpf_copy_bit(k, KPF_RECLAIM, PG_reclaim);
+
+ u |= kpf_copy_bit(k, KPF_SWAPCACHE, PG_swapcache);
+ u |= kpf_copy_bit(k, KPF_SWAPBACKED, PG_swapbacked);
+
+#ifdef CONFIG_UNEVICTABLE_LRU
+ u |= kpf_copy_bit(k, KPF_UNEVICTABLE, PG_unevictable);
+ u |= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
+#endif
+
+#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
+ u |= kpf_copy_bit(k, KPF_UNCACHED, PG_uncached);
+#endif
+
+ u |= kpf_copy_bit(k, KPF_RESERVED, PG_reserved);
+ u |= kpf_copy_bit(k, KPF_MAPPEDTODISK, PG_mappedtodisk);
+ u |= kpf_copy_bit(k, KPF_PRIVATE, PG_private);
+ u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
+ u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
+ u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
+
+ return u;
+};
static ssize_t kpageflags_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
@@ -93,7 +198,6 @@ static ssize_t kpageflags_read(struct fi
unsigned long src = *ppos;
unsigned long pfn;
ssize_t ret = 0;
- u64 kflags, uflags;
pfn = src / KPMSIZE;
count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
@@ -105,24 +209,8 @@ static ssize_t kpageflags_read(struct fi
ppage = pfn_to_page(pfn);
else
ppage = NULL;
- if (!ppage)
- kflags = 0;
- else
- kflags = ppage->flags;
-
- uflags = kpf_copy_bit(kflags, KPF_LOCKED, PG_locked) |
- kpf_copy_bit(kflags, KPF_ERROR, PG_error) |
- kpf_copy_bit(kflags, KPF_REFERENCED, PG_referenced) |
- kpf_copy_bit(kflags, KPF_UPTODATE, PG_uptodate) |
- kpf_copy_bit(kflags, KPF_DIRTY, PG_dirty) |
- kpf_copy_bit(kflags, KPF_LRU, PG_lru) |
- kpf_copy_bit(kflags, KPF_ACTIVE, PG_active) |
- kpf_copy_bit(kflags, KPF_SLAB, PG_slab) |
- kpf_copy_bit(kflags, KPF_WRITEBACK, PG_writeback) |
- kpf_copy_bit(kflags, KPF_RECLAIM, PG_reclaim) |
- kpf_copy_bit(kflags, KPF_BUDDY, PG_buddy);
- if (put_user(uflags, out)) {
+ if (put_user(get_uflags(ppage), out)) {
ret = -EFAULT;
break;
}
_
Patches currently in -mm which might be from fengguang.wu@xxxxxxxxx are
origin.patch
linux-next.patch
readahead-make-mmap_miss-an-unsigned-int.patch
readahead-move-max_sane_readahead-calls-into-force_page_cache_readahead.patch
readahead-apply-max_sane_readahead-limit-in-ondemand_readahead.patch
readahead-remove-one-unnecessary-radix-tree-lookup.patch
readahead-increase-interleaved-readahead-size.patch
readahead-remove-sync-async-readahead-call-dependency.patch
readahead-clean-up-and-simplify-the-code-for-filemap-page-fault-readahead.patch
readahead-sequential-mmap-readahead.patch
readahead-enforce-full-readahead-size-on-async-mmap-readahead.patch
readahead-record-mmap-read-around-states-in-file_ra_state.patch
radix-tree-add-radix_tree_prev_hole.patch
readahead-move-the-random-read-case-to-bottom.patch
readahead-introduce-context-readahead-algorithm.patch
readahead-introduce-context-readahead-algorithm-update.patch
readahead-remove-redundant-test-in-shrink_readahead_size_eio.patch
readahead-enforce-full-sync-mmap-readahead-size.patch
mm-introduce-pagehuge-for-testing-huge-gigantic-pages.patch
slob-use-pg_slab-for-identifying-slob-pages.patch
proc-kpagecount-kpageflags-code-cleanup.patch
proc-export-more-page-flags-in-proc-kpageflags.patch
pagemap-document-clarifications.patch
pagemap-document-9-more-exported-page-flags.patch
pagemap-add-page-types-tool.patch
pagemap-export-pg_hwpoison.patch
vmscan-cleanup-the-scan-batching-code.patch
vmscan-dont-export-nr_saved_scan-in-proc-zoneinfo.patch
vmscan-zvc-updates-in-shrink_active_list-can-be-done-once.patch
inotify-reimplement-inotify-using-fsnotify-report-rounded-up-event-size-to-user-space.patch
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