I/O priority support with cfq scheduler (needs new kernel patch)

[vuplus_dvbapp] / lib / base / ioprio.cpp

diff --git a/lib/base/ioprio.cpp b/lib/base/ioprio.cpp
new file mode 100644 (file)
index 0000000..2ada736
--- /dev/null
+++ b/lib/base/ioprio.cpp
@@ -0,0 +1,78 @@
+#include <lib/base/ioprio.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <getopt.h>
+#include <unistd.h>
+#include <sys/ptrace.h>
+#include <asm/unistd.h>
+
+#include <lib/base/eerror.h>
+
+extern "C" int sys_ioprio_set(int, int, int);
+extern "C" int sys_ioprio_get(int, int);
+
+#if defined(__i386__)
+#define __NR_ioprio_set                289
+#define __NR_ioprio_get                290
+#elif defined(__ppc__)
+#define __NR_ioprio_set                273
+#define __NR_ioprio_get                274
+#elif defined(__x86_64__)
+#define __NR_ioprio_set                251
+#define __NR_ioprio_get                252
+#elif defined(__ia64__)
+#define __NR_ioprio_set                1274
+#define __NR_ioprio_get                1275
+#elif defined(__mips__)
+#define __NR_ioprio_set                4284
+#define __NR_ioprio_get                4285
+#else
+#error "Unsupported arch"
+#endif
+
+_syscall3(int, ioprio_set, int, which, int, who, int, ioprio);
+_syscall2(int, ioprio_get, int, which, int, who);
+
+#define IOPRIO_CLASS_SHIFT     13
+
+enum {
+       IOPRIO_WHO_PROCESS = 1,
+       IOPRIO_WHO_PGRP,
+       IOPRIO_WHO_USER,
+};
+
+const char *to_prio[] = { "none", "realtime", "best-effort", "idle", };
+
+void setIoPrio(int prio_class, int prio)
+{
+       if (prio_class < 0 || prio_class > 3)
+       {
+               eDebug("prio class(%d) out of valid range (0..3)", prio_class);
+               return;
+       }
+       if (prio < 0 || prio > 7)
+       {
+               eDebug("prio level(%d) out of range (0..7)", prio);
+               return;
+       }
+       if (ioprio_set(IOPRIO_WHO_PROCESS, 0 /*pid 0 .. current process*/, prio | prio_class << IOPRIO_CLASS_SHIFT) == -1)
+               eDebug("setIoPrio failed (%m) !");
+       else
+               eDebug("setIoPrio %s level %d ok", to_prio[prio_class], prio);
+}
+
+void printIoPrio()
+{
+       int pid = 0, ioprio = ioprio_get(IOPRIO_WHO_PROCESS, pid);
+
+       eDebug("pid=%d, %d", pid, ioprio);
+
+       if (ioprio == -1)
+               eDebug("ioprio_get(%m)");
+       else {
+               int ioprio_class = ioprio >> IOPRIO_CLASS_SHIFT;
+               ioprio = ioprio & 0xff;
+               eDebug("%s: prio %d", to_prio[ioprio_class], ioprio);
+       }
+}