page-types: make standalone pagemap/kpageflags read routines
Refactor the code to be more modular and easier to reuse.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
index 6bdcc06..18e891a 100644
--- a/Documentation/vm/page-types.c
+++ b/Documentation/vm/page-types.c
@@ -161,8 +161,6 @@
static unsigned long pg_end[MAX_VMAS];
static unsigned long voffset;
-static int pagemap_fd;
-
#define MAX_BIT_FILTERS 64
static int nr_bit_filters;
static uint64_t opt_mask[MAX_BIT_FILTERS];
@@ -170,7 +168,7 @@
static int page_size;
-#define PAGES_BATCH (64 << 10) /* 64k pages */
+static int pagemap_fd;
static int kpageflags_fd;
#define HASH_SHIFT 13
@@ -226,6 +224,62 @@
return fd;
}
+/*
+ * pagemap/kpageflags routines
+ */
+
+static unsigned long do_u64_read(int fd, char *name,
+ uint64_t *buf,
+ unsigned long index,
+ unsigned long count)
+{
+ long bytes;
+
+ if (index > ULONG_MAX / 8)
+ fatal("index overflow: %lu\n", index);
+
+ if (lseek(fd, index * 8, SEEK_SET) < 0) {
+ perror(name);
+ exit(EXIT_FAILURE);
+ }
+
+ bytes = read(fd, buf, count * 8);
+ if (bytes < 0) {
+ perror(name);
+ exit(EXIT_FAILURE);
+ }
+ if (bytes % 8)
+ fatal("partial read: %lu bytes\n", bytes);
+
+ return bytes / 8;
+}
+
+static unsigned long kpageflags_read(uint64_t *buf,
+ unsigned long index,
+ unsigned long pages)
+{
+ return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
+}
+
+static unsigned long pagemap_read(uint64_t *buf,
+ unsigned long index,
+ unsigned long pages)
+{
+ return do_u64_read(pagemap_fd, "/proc/pid/pagemap", buf, index, pages);
+}
+
+static unsigned long pagemap_pfn(uint64_t val)
+{
+ unsigned long pfn;
+
+ if (val & PM_PRESENT)
+ pfn = PM_PFRAME(val);
+ else
+ pfn = 0;
+
+ return pfn;
+}
+
/*
* page flag names
@@ -432,79 +486,53 @@
total_pages++;
}
+#define KPAGEFLAGS_BATCH (64 << 10) /* 64k pages */
static void walk_pfn(unsigned long index, unsigned long count)
{
+ uint64_t buf[KPAGEFLAGS_BATCH];
unsigned long batch;
- unsigned long n;
+ unsigned long pages;
unsigned long i;
- if (index > ULONG_MAX / KPF_BYTES)
- fatal("index overflow: %lu\n", index);
-
- lseek(kpageflags_fd, index * KPF_BYTES, SEEK_SET);
-
while (count) {
- uint64_t kpageflags_buf[KPF_BYTES * PAGES_BATCH];
-
- batch = min_t(unsigned long, count, PAGES_BATCH);
- n = read(kpageflags_fd, kpageflags_buf, batch * KPF_BYTES);
- if (n == 0)
+ batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH);
+ pages = kpageflags_read(buf, index, batch);
+ if (pages == 0)
break;
- if (n < 0) {
- perror(PROC_KPAGEFLAGS);
- exit(EXIT_FAILURE);
- }
- if (n % KPF_BYTES != 0)
- fatal("partial read: %lu bytes\n", n);
- n = n / KPF_BYTES;
+ for (i = 0; i < pages; i++)
+ add_page(index + i, buf[i]);
- for (i = 0; i < n; i++)
- add_page(index + i, kpageflags_buf[i]);
-
- index += batch;
- count -= batch;
+ index += pages;
+ count -= pages;
}
}
-
-#define PAGEMAP_BATCH 4096
-static unsigned long task_pfn(unsigned long pgoff)
+#define PAGEMAP_BATCH (64 << 10)
+static void walk_vma(unsigned long index, unsigned long count)
{
- static uint64_t buf[PAGEMAP_BATCH];
- static unsigned long start;
- static long count;
- uint64_t pfn;
+ uint64_t buf[PAGEMAP_BATCH];
+ unsigned long batch;
+ unsigned long pages;
+ unsigned long pfn;
+ unsigned long i;
- if (pgoff < start || pgoff >= start + count) {
- if (lseek64(pagemap_fd,
- (uint64_t)pgoff * PM_ENTRY_BYTES,
- SEEK_SET) < 0) {
- perror("pagemap seek");
- exit(EXIT_FAILURE);
+ while (count) {
+ batch = min_t(unsigned long, count, PAGEMAP_BATCH);
+ pages = pagemap_read(buf, index, batch);
+ if (pages == 0)
+ break;
+
+ for (i = 0; i < pages; i++) {
+ pfn = pagemap_pfn(buf[i]);
+ voffset = index + i;
+ if (pfn)
+ walk_pfn(pfn, 1);
}
- count = read(pagemap_fd, buf, sizeof(buf));
- if (count == 0)
- return 0;
- if (count < 0) {
- perror("pagemap read");
- exit(EXIT_FAILURE);
- }
- if (count % PM_ENTRY_BYTES) {
- fatal("pagemap read not aligned.\n");
- exit(EXIT_FAILURE);
- }
- count /= PM_ENTRY_BYTES;
- start = pgoff;
+
+ index += pages;
+ count -= pages;
}
-
- pfn = buf[pgoff - start];
- if (pfn & PM_PRESENT)
- pfn = PM_PFRAME(pfn);
- else
- pfn = 0;
-
- return pfn;
}
static void walk_task(unsigned long index, unsigned long count)
@@ -524,11 +552,7 @@
index = min_t(unsigned long, pg_end[i], end);
assert(voffset < index);
- for (; voffset < index; voffset++) {
- unsigned long pfn = task_pfn(voffset);
- if (pfn)
- walk_pfn(pfn, 1);
- }
+ walk_vma(voffset, index - voffset);
}
}