core: Add I/O pressure support

src/basic/psi-util.c

@@ -116,11 +116,17 @@ const PressureResourceInfo pressure_resource_info[_PRESSURE_RESOURCE_MAX] = {
                 .env_watch = "CPU_PRESSURE_WATCH",
                 .env_write = "CPU_PRESSURE_WRITE",
         },
+        [PRESSURE_IO] = {
+                .name      = "io",
+                .env_watch = "IO_PRESSURE_WATCH",
+                .env_write = "IO_PRESSURE_WRITE",
+        },
 };
 
 static const char* const pressure_resource_table[_PRESSURE_RESOURCE_MAX] = {
         [PRESSURE_MEMORY] = "memory",
         [PRESSURE_CPU]    = "cpu",
+        [PRESSURE_IO]     = "io",
 };
 
 DEFINE_STRING_TABLE_LOOKUP(pressure_resource, PressureResource);

src/basic/psi-util.h

@@ -12,6 +12,7 @@ typedef enum PressureType {
 typedef enum PressureResource {
         PRESSURE_MEMORY,
         PRESSURE_CPU,
+        PRESSURE_IO,
         _PRESSURE_RESOURCE_MAX,
         _PRESSURE_RESOURCE_INVALID = -EINVAL,
 } PressureResource;