sreadahead: Add a patch to set the app to io-idle running status.

This patch sets the sreadahead to io-idle stauts when it is running,
so that sreadahead will not preempt IO with other apps.

2 files changed, 40 insertions, 0 deletions

diff --git a/meta-moblin/packages/sreadahead/sreadahead-0.02/set_to_idle.patch b/meta-moblin/packages/sreadahead/sreadahead-0.02/set_to_idle.patch
new file mode 100644
index 0000000000..b48659048a
--- /dev/null
+++ b/meta-moblin/packages/sreadahead/sreadahead-0.02/set_to_idle.patch
@@ -0,0 +1,39 @@
+diff -Naurp sreadahead-0.02/readahead.c sreadahead-0.02-nice/readahead.c
+--- sreadahead-0.02/readahead.c 2008-11-06 00:57:17.000000000 -0500
++++ sreadahead-0.02-nice/readahead.c    2008-11-06 02:28:29.000000000 -0500
+@@ -26,7 +26,18 @@
+ #include <errno.h>
+ 
+ #include "readahead.h"
++#include <sys/syscall.h>
+ 
++# if defined(__i386__)
++#  define __NR_ioprio_set      289
++# elif defined(__x86_64__)
++#  define __NR_ioprio_set      251
++# else
++#  error "Unsupported arch"
++# endif
++
++#define IOPRIO_WHO_PROCESS     1
++#define IOPRIO_CLASS_SHIFT     13
+ #define MAXR 1024
+ static struct readahead files[MAXR];
+ static unsigned int total_files = 0;
+@@ -68,7 +79,15 @@ void *one_thread(void *ptr)
+ 
+ int main(int argc, char **argv)
+ {
+-       FILE *file = fopen("/etc/readahead.packed", "r");
++       int iopriority = 7; /* hard code for idle */
++       int iopriority_class = 3; /* 3 stands for idle */
++       int pid = 0;
++       FILE *file;
++
++       if (syscall(__NR_ioprio_set, IOPRIO_WHO_PROCESS, pid, iopriority | iopriority_class << IOPRIO_CLASS_SHIFT) == -1)
++               perror("Can not set priority to idle class");
++
++       file = fopen("/etc/readahead.packed", "r");
+        if (!file) {
+                perror("Couldnt open /etc/readahead.packed");
+                return -errno;
diff --git a/meta-moblin/packages/sreadahead/sreadahead_0.02.bb b/meta-moblin/packages/sreadahead/sreadahead_0.02.bb
index 1ca5f16557..b7341010aa 100644
--- a/meta-moblin/packages/sreadahead/sreadahead_0.02.bb
+++ b/meta-moblin/packages/sreadahead/sreadahead_0.02.bb
@@ -9,6 +9,7 @@ inherit update-rc.d
 SRC_URI = "http://www.moblin.org/sites/all/files/sreadahead-${PV}.tar.gz \
           file://sreadahead-0.02-make.patch;patch=1 \
           file://readahead_c.patch;patch=1 \
+          file://set_to_idle.patch;patch=1 \
           file://sreadahead-generate.sh \
           file://sreadahead.sh"