This patch introduces a new mode for file scanning, where when page-types
is called with -f <filepath>, it registers a given file to /proc/kpagecache,
and scans pages in the pagecache of the file.
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
---
tools/vm/page-types.c | 117 +++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 101 insertions(+), 16 deletions(-)
diff --git v3.14-rc6.orig/tools/vm/page-types.c v3.14-rc6/tools/vm/page-types.c
index f9be24d9efac..e9f1882378c7 100644
--- v3.14-rc6.orig/tools/vm/page-types.c
+++ v3.14-rc6/tools/vm/page-types.c
@@ -33,6 +33,7 @@
#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/mount.h>
+#include <sys/stat.h>
#include <sys/statfs.h>
#include "../../include/uapi/linux/magic.h"
#include "../../include/uapi/linux/kernel-page-flags.h"
@@ -75,6 +76,7 @@
#define KPF_BYTES 8
#define PROC_KPAGEFLAGS "/proc/kpageflags"
+#define PROC_KPAGECACHE "/proc/kpagecache"
/* [32-] kernel hacking assistances */
#define KPF_RESERVED 32
@@ -158,6 +160,7 @@ static int opt_raw; /* for kernel developers */
static int opt_list; /* list pages (in ranges) */
static int opt_no_summary; /* don't show summary */
static pid_t opt_pid; /* process to walk */
+static int opt_file; /* walk over pagecache of file */
#define MAX_ADDR_RANGES 1024
static int nr_addr_ranges;
@@ -178,6 +181,7 @@ static int page_size;
static int pagemap_fd;
static int kpageflags_fd;
+static int kpagecache_fd;
static int opt_hwpoison;
static int opt_unpoison;
@@ -276,6 +280,13 @@ static unsigned long kpageflags_read(uint64_t *buf,
return do_u64_read(kpageflags_fd, PROC_KPAGEFLAGS, buf, index, pages);
}
+static unsigned long kpagecache_read(uint64_t *buf,
+ unsigned long index,
+ unsigned long pages)
+{
+ return do_u64_read(kpagecache_fd, PROC_KPAGECACHE, buf, index, pages);
+}
+
static unsigned long pagemap_read(uint64_t *buf,
unsigned long index,
unsigned long pages)
@@ -358,7 +369,7 @@ static void show_page_range(unsigned long voffset,
}
if (count) {
- if (opt_pid)
+ if (opt_pid || opt_file)
printf("%lx\t", voff);
printf("%lx\t%lx\t%s\n",
index, count, page_flag_name(flags0));
@@ -378,6 +389,19 @@ static void show_page(unsigned long voffset,
printf("%lx\t%s\n", offset, page_flag_name(flags));
}
+#define __NR_PAGECACHE_TAGS 4
+#define KPC_TAGS_BITS __NR_PAGECACHE_TAGS
+#define KPC_TAGS_OFFSET (64 - KPC_TAGS_BITS)
+#define KPC_TAGS_MASK (((1ULL << KPC_TAGS_BITS) - 1) << KPC_TAGS_OFFSET)
+#define KPC_TAGS(entry) ((entry & KPC_TAGS_MASK) >> KPC_TAGS_OFFSET)
+
+static void show_file_page(unsigned long voffset,
+ unsigned long offset, uint64_t flags, uint64_t entry)
+{
+ printf("%lx\t%lx\t%llx\t%s\n",
+ voffset, offset, KPC_TAGS(entry), page_flag_name(flags));
+}
+
static void show_summary(void)
{
size_t i;
@@ -564,10 +588,15 @@ static void add_page(unsigned long voffset,
if (opt_unpoison)
unpoison_page(offset);
- if (opt_list == 1)
- show_page_range(voffset, offset, flags);
- else if (opt_list == 2)
- show_page(voffset, offset, flags);
+ if (opt_pid || !opt_file) {
+ if (opt_list == 1)
+ show_page_range(voffset, offset, flags);
+ else if (opt_list == 2)
+ show_page(voffset, offset, flags);
+ } else {
+ if (opt_list)
+ show_file_page(voffset, offset, flags, pme);
+ }
nr_pages[hash_slot(flags)]++;
total_pages++;
@@ -646,6 +675,41 @@ static void walk_task(unsigned long index, unsigned long count)
}
}
+char *kpagecache_path;
+struct stat kpagecache_stat;
+
+#define KPAGECACHE_BATCH (64 << 10) /* 64k pages */
+static void walk_file(unsigned long index, unsigned long count)
+{
+ uint64_t buf[KPAGECACHE_BATCH];
+ unsigned long batch;
+ unsigned long pages;
+ unsigned long pfn;
+ unsigned long i;
+ unsigned long end_index = count;
+ unsigned long size;
+
+ stat(kpagecache_path, &kpagecache_stat);
+ size = kpagecache_stat.st_size;
+ if (size > 0)
+ size = (size - 1) / 4096;
+ end_index = min_t(unsigned long, index + count - 1, size);
+ while (index <= end_index) {
+ batch = min_t(unsigned long, count, PAGEMAP_BATCH);
+ pages = kpagecache_read(buf, index, batch);
+ if (pages == 0)
+ break;
+ for (i = 0; i < pages; i++) {
+ pfn = buf[i] & ((1UL << 52) - 1UL);
+ if (pfn)
+ walk_pfn(index + i, pfn, 1, buf[i]);
+ }
+
+ index += pages;
+ count -= pages;
+ }
+}
+
static void add_addr_range(unsigned long offset, unsigned long size)
{
if (nr_addr_ranges >= MAX_ADDR_RANGES)
@@ -666,10 +730,12 @@ static void walk_addr_ranges(void)
add_addr_range(0, ULONG_MAX);
for (i = 0; i < nr_addr_ranges; i++)
- if (!opt_pid)
- walk_pfn(0, opt_offset[i], opt_size[i], 0);
- else
+ if (opt_pid)
walk_task(opt_offset[i], opt_size[i]);
+ else if (opt_file)
+ walk_file(opt_offset[i], opt_size[i]);
+ else
+ walk_pfn(0, opt_offset[i], opt_size[i], 0);
close(kpageflags_fd);
}
@@ -699,9 +765,7 @@ static void usage(void)
" -a|--addr addr-spec Walk a range of pages\n"
" -b|--bits bits-spec Walk pages with specified bits\n"
" -p|--pid pid Walk process address space\n"
-#if 0 /* planned features */
" -f|--file filename Walk file address space\n"
-#endif
" -l|--list Show page details in ranges\n"
" -L|--list-each Show page details one by one\n"
" -N|--no-summary Don't show summary info\n"
@@ -801,6 +865,18 @@ static void parse_pid(const char *str)
static void parse_file(const char *name)
{
+ int ret;
+ kpagecache_path = (char *)name;
+ kpagecache_fd = checked_open(PROC_KPAGECACHE, O_RDWR);
+ ret = write(kpagecache_fd, name, strlen(name));
+ if (ret != (int)strlen(name))
+ fatal("Failed to set file on %s\n", PROC_KPAGECACHE);
+}
+
+static void close_kpagecache(void)
+{
+ write(kpagecache_fd, NULL, 1);
+ close(kpagecache_fd);
}
static void parse_addr_range(const char *optarg)
@@ -953,6 +1029,7 @@ int main(int argc, char *argv[])
break;
case 'f':
parse_file(optarg);
+ opt_file = 1;
break;
case 'a':
parse_addr_range(optarg);
@@ -989,18 +1066,26 @@ int main(int argc, char *argv[])
}
}
- if (opt_list && opt_pid)
- printf("voffset\t");
- if (opt_list == 1)
- printf("offset\tlen\tflags\n");
- if (opt_list == 2)
- printf("offset\tflags\n");
+ if (opt_pid || !opt_file) {
+ if (opt_pid)
+ printf("voffset\t");
+ if (opt_list == 1)
+ printf("offset\tlen\tflags\n");
+ if (opt_list == 2)
+ printf("offset\tflags\n");
+ } else {
+ if (opt_list)
+ printf("pgoff\tpfn\ttags\tflags\n");
+ }
walk_addr_ranges();
if (opt_list == 1)
show_page_range(0, 0, 0); /* drain the buffer */
+ if (opt_file == 1)
+ close_kpagecache();
+
if (opt_no_summary)
return 0;
--
1.8.5.3
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