libudev: allocate udev_device->envp[] dynamically

Measured 2% _user_ cpu time reduction on EeePC coldplug.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>

diff --git a/udev/lib/libudev-device.c b/udev/lib/libudev-device.c
index e4cbd8e6895539c9ba9127124ecb0e3528e599bf..86f7918d49ac2514cdfd54c9eb08885e98f41e58 100644 (file)
--- a/udev/lib/libudev-device.c
+++ b/udev/lib/libudev-device.c
@@ -31,6 +31,8 @@
 #include "libudev.h"
 #include "libudev-private.h"
 
+#define ENVP_SIZE 128
+
 struct udev_device {
        int refcount;
        struct udev *udev;
@@ -46,7 +48,7 @@ struct udev_device {
        struct udev_list_node devlinks_list;
        int devlinks_uptodate;
        struct udev_list_node properties_list;
-       char *envp[128];
+       char **envp;
        int envp_uptodate;
        char *driver;
        int driver_set;
@@ -610,8 +612,11 @@ void udev_device_unref(struct udev_device *udev_device)
        free(udev_device->devpath_old);
        free(udev_device->physdevpath);
        udev_list_cleanup_entries(udev_device->udev, &udev_device->sysattr_list);
-       for (i = 0; i < ARRAY_SIZE(udev_device->envp) && udev_device->envp[i] != NULL; i++)
-               free(udev_device->envp[i]);
+       if (udev_device->envp != NULL) {
+               for (i = 0; i < ENVP_SIZE && udev_device->envp[i] != NULL; i++)
+                       free(udev_device->envp[i]);
+               free(udev_device->envp);
+       }
        info(udev_device->udev, "udev_device: %p released\n", udev_device);
        free(udev_device);
 }
@@ -1013,14 +1018,18 @@ char **udev_device_get_properties_envp(struct udev_device *udev_device)
                unsigned int i;
                struct udev_list_entry *list_entry;
 
-               for (i = 0; i < ARRAY_SIZE(udev_device->envp) && udev_device->envp[i] != NULL; i++)
-                       free(udev_device->envp[i]);
+               if (udev_device->envp) {
+                       for (i = 0; i < 128 && udev_device->envp[i] != NULL; i++)
+                               free(udev_device->envp[i]);
+               } else
+                       udev_device->envp = malloc(sizeof(char *) * ENVP_SIZE);
+
                i = 0;
                udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
                        asprintf(&udev_device->envp[i++], "%s=%s",
                                 udev_list_entry_get_name(list_entry),
                                 udev_list_entry_get_value(list_entry));
-                       if (i+1 >= ARRAY_SIZE(udev_device->envp))
+                       if (i+1 >= ENVP_SIZE)
                                break;
                }
                udev_device->envp[i] = NULL;