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-rw-r--r--src/vlib/linux/sysfs.c250
1 files changed, 250 insertions, 0 deletions
diff --git a/src/vlib/linux/sysfs.c b/src/vlib/linux/sysfs.c
new file mode 100644
index 00000000000..f92f9ef564e
--- /dev/null
+++ b/src/vlib/linux/sysfs.c
@@ -0,0 +1,250 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+
+clib_error_t *
+vlib_sysfs_write (char *file_name, char *fmt, ...)
+{
+ u8 *s;
+ int fd;
+ clib_error_t *error = 0;
+
+ fd = open (file_name, O_WRONLY);
+ if (fd < 0)
+ return clib_error_return_unix (0, "open `%s'", file_name);
+
+ va_list va;
+ va_start (va, fmt);
+ s = va_format (0, fmt, &va);
+ va_end (va);
+
+ if (write (fd, s, vec_len (s)) < 0)
+ error = clib_error_return_unix (0, "write `%s'", file_name);
+
+ vec_free (s);
+ close (fd);
+ return error;
+}
+
+clib_error_t *
+vlib_sysfs_read (char *file_name, char *fmt, ...)
+{
+ unformat_input_t input;
+ u8 *s = 0;
+ int fd;
+ ssize_t sz;
+ uword result;
+
+ fd = open (file_name, O_RDONLY);
+ if (fd < 0)
+ return clib_error_return_unix (0, "open `%s'", file_name);
+
+ vec_validate (s, 4095);
+
+ sz = read (fd, s, vec_len (s));
+ if (sz < 0)
+ {
+ close (fd);
+ vec_free (s);
+ return clib_error_return_unix (0, "read `%s'", file_name);
+ }
+
+ _vec_len (s) = sz;
+ unformat_init_vector (&input, s);
+
+ va_list va;
+ va_start (va, fmt);
+ result = va_unformat (&input, fmt, &va);
+ va_end (va);
+
+ vec_free (s);
+ close (fd);
+
+ if (result == 0)
+ return clib_error_return (0, "unformat error");
+
+ return 0;
+}
+
+u8 *
+vlib_sysfs_link_to_name (char *link)
+{
+ char *p, buffer[64];
+ unformat_input_t in;
+ u8 *s = 0;
+ int r;
+
+ r = readlink (link, buffer, sizeof (buffer) - 1);
+
+ if (r < 0)
+ return 0;
+
+ buffer[r] = 0;
+ p = strrchr (buffer, '/');
+
+ if (!p)
+ return 0;
+
+ unformat_init_string (&in, p + 1, strlen (p + 1));
+ if (unformat (&in, "%s", &s) != 1)
+ clib_unix_warning ("no string?");
+ unformat_free (&in);
+
+ return s;
+}
+
+clib_error_t *
+vlib_sysfs_set_nr_hugepages (unsigned int numa_node, int page_size, int nr)
+{
+ clib_error_t *error = 0;
+ struct stat sb;
+ u8 *p = 0;
+
+ p = format (p, "/sys/devices/system/node/node%u%c", numa_node, 0);
+
+ if (stat ((char *) p, &sb) == 0)
+ {
+ if (S_ISDIR (sb.st_mode) == 0)
+ {
+ error = clib_error_return (0, "'%s' is not directory", p);
+ goto done;
+ }
+ }
+ else if (numa_node == 0)
+ {
+ vec_reset_length (p);
+ p = format (p, "/sys/kernel/mm%c", 0);
+ if (stat ((char *) p, &sb) < 0 || S_ISDIR (sb.st_mode) == 0)
+ {
+ error = clib_error_return (0, "'%s' does not exist or it is not "
+ "directory", p);
+ goto done;
+ }
+ }
+ else
+ {
+ error = clib_error_return (0, "'%s' does not exist", p);
+ goto done;
+ }
+
+ _vec_len (p) -= 1;
+ p = format (p, "/hugepages/hugepages-%ukB/nr_hugepages%c", page_size, 0);
+ vlib_sysfs_write ((char *) p, "%d", nr);
+
+done:
+ vec_free (p);
+ return error;
+}
+
+
+static clib_error_t *
+vlib_sysfs_get_xxx_hugepages (char *type, unsigned int numa_node,
+ int page_size, int *val)
+{
+ clib_error_t *error = 0;
+ struct stat sb;
+ u8 *p = 0;
+
+ p = format (p, "/sys/devices/system/node/node%u%c", numa_node, 0);
+
+ if (stat ((char *) p, &sb) == 0)
+ {
+ if (S_ISDIR (sb.st_mode) == 0)
+ {
+ error = clib_error_return (0, "'%s' is not directory", p);
+ goto done;
+ }
+ }
+ else if (numa_node == 0)
+ {
+ vec_reset_length (p);
+ p = format (p, "/sys/kernel/mm%c", 0);
+ if (stat ((char *) p, &sb) < 0 || S_ISDIR (sb.st_mode) == 0)
+ {
+ error = clib_error_return (0, "'%s' does not exist or it is not "
+ "directory", p);
+ goto done;
+ }
+ }
+ else
+ {
+ error = clib_error_return (0, "'%s' does not exist", p);
+ goto done;
+ }
+
+ _vec_len (p) -= 1;
+ p = format (p, "/hugepages/hugepages-%ukB/%s_hugepages%c", page_size,
+ type, 0);
+ error = vlib_sysfs_read ((char *) p, "%d", val);
+
+done:
+ vec_free (p);
+ return error;
+}
+
+clib_error_t *
+vlib_sysfs_get_free_hugepages (unsigned int numa_node, int page_size, int *v)
+{
+ return vlib_sysfs_get_xxx_hugepages ("free", numa_node, page_size, v);
+}
+
+clib_error_t *
+vlib_sysfs_get_nr_hugepages (unsigned int numa_node, int page_size, int *v)
+{
+ return vlib_sysfs_get_xxx_hugepages ("nr", numa_node, page_size, v);
+}
+
+clib_error_t *
+vlib_sysfs_get_surplus_hugepages (unsigned int numa_node, int page_size,
+ int *v)
+{
+ return vlib_sysfs_get_xxx_hugepages ("surplus", numa_node, page_size, v);
+}
+
+clib_error_t *
+vlib_sysfs_prealloc_hugepages (unsigned int numa_node, int page_size, int nr)
+{
+ clib_error_t *error = 0;
+ int n, needed;
+ error = vlib_sysfs_get_free_hugepages (numa_node, page_size, &n);
+ if (error)
+ return error;
+ needed = nr - n;
+ if (needed <= 0)
+ return 0;
+
+ error = vlib_sysfs_get_nr_hugepages (numa_node, page_size, &n);
+ if (error)
+ return error;
+ clib_warning ("pre-allocating %u additional %uK hugepages on numa node %u",
+ needed, page_size, numa_node);
+ return vlib_sysfs_set_nr_hugepages (numa_node, page_size, n + needed);
+}
+
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */