From: Matteo Croce <teknora...@meta.com>
Under Linux, add a --memory flag which allows to show cache memory usage
of files:
$ truncate -s100M file
$ du file
0 file
$ dd status=none bs=1M count=5 if=file of=/dev/null
$ du --memory --human file
10M file
$ dd status=none bs=1M skip=30 count=5 if=file of=/dev/null
$ du --memory --human file
21M file
$ cat file >/dev/null
$ du --memory --human file
100M file
---
src/du.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 75 insertions(+), 1 deletion(-)
diff --git a/src/du.c b/src/du.c
index 0e5d860a9..de8dfde1e 100644
--- a/src/du.c
+++ b/src/du.c
@@ -43,6 +43,26 @@
#include "xstrtol.h"
#include "xstrtol-error.h"
+#ifdef __linux__
+
+#include <sys/syscall.h>
+
+#ifdef __NR_cachestat
+
+#include <linux/mman.h>
+
+static long page_size;
+
+static int
+cachestat(int fd, struct cachestat_range *cstat_range,
+ struct cachestat *cstat, unsigned int flags)
+{
+ return syscall(__NR_cachestat, fd, cstat_range, cstat, flags);
+}
+
+#endif
+#endif
+
extern bool fts_debug;
/* The official name of this program (e.g., no 'g' prefix). */
@@ -165,6 +185,9 @@ static bool opt_inodes = false;
/* If true, print most recently modified date, using the specified format. */
static bool opt_time = false;
+/* If true, print memory usage. */
+static bool opt_memory = false;
+
/* Type of time to display. controlled by --time. */
enum time_type
@@ -229,6 +252,9 @@ static struct option const long_options[] =
{"inodes", no_argument, nullptr, INODES_OPTION},
{"si", no_argument, nullptr, HUMAN_SI_OPTION},
{"max-depth", required_argument, nullptr, 'd'},
+#ifdef __NR_cachestat
+ {"memory", no_argument, nullptr, 'M'},
+#endif
{"null", no_argument, nullptr, '0'},
{"no-dereference", no_argument, nullptr, 'P'},
{"one-file-system", no_argument, nullptr, 'x'},
@@ -321,6 +347,13 @@ Summarize device usage of the set of FILEs, recursively
for directories.\n\
\n\
--inodes list inode usage information instead of block usage\n\
"), stdout);
+
+#ifdef __NR_cachestat
+ fputs (_("\
+ -M, --memory print cache usage instead of block usage\n\
+"), stdout);
+#endif
+
fputs (_("\
-k like --block-size=1K\n\
-L, --dereference dereference all symbolic links\n\
@@ -465,6 +498,35 @@ mount_point_in_fts_cycle (FTSENT const *ent)
return false;
}
+static long get_cacheinfo (MAYBE_UNUSED const char *file)
+{
+#ifdef __NR_cachestat
+ struct cachestat_range cstat_range = { 0 };
+ struct cachestat cstat;
+ int fd = open (file, O_RDONLY | O_CLOEXEC);
+ int ret;
+
+ if (fd == -1)
+ {
+ error (0, errno, _("cannot open %s"), quoteaf (file));
+ return 0;
+ }
+
+ ret = cachestat(fd, &cstat_range, &cstat, 0);
+ close (fd);
+
+ if (ret == -1)
+ {
+ error (0, errno, _("cannot get memory usage"));
+ return 0;
+ }
+
+ return cstat.nr_cache * page_size;
+#else
+ return 0;
+#endif
+}
+
/* This function is called once for every file system object that fts
encounters. fts does a depth-first traversal. This function knows
that and accumulates per-directory totals based on changes in
@@ -571,6 +633,7 @@ process_file (FTS *fts, FTSENT *ent)
}
duinfo_set (&dui,
+ opt_memory ? get_cacheinfo (file) :
(apparent_size
? (usable_st_size (sb) ? MAX (0, sb->st_size) : 0)
: (uintmax_t) STP_NBLOCKS (sb) * ST_NBLOCKSIZE),
@@ -738,7 +801,11 @@ main (int argc, char **argv)
while (true)
{
int oi = -1;
- int c = getopt_long (argc, argv, "0abd:chHklmst:xB:DLPSX:",
+ int c = getopt_long (argc, argv, "0abd:chHklmst:xB:DLPSX:"
+#ifdef __NR_cachestat
+ "M"
+#endif
+ ,
long_options, &oi);
if (c == -1)
break;
@@ -856,6 +923,13 @@ main (int argc, char **argv)
symlink_deref_bits = FTS_LOGICAL;
break;
+#ifdef __NR_cachestat
+ case 'M':
+ opt_memory = true;
+ page_size = sysconf(_SC_PAGE_SIZE);
+ break;
+#endif
+
case 'P': /* --no-dereference */
symlink_deref_bits = FTS_PHYSICAL;
break;
--
2.49.0
