ionice: add -t option

This patch allows "tolerant" behavior, i.e. proceeding even if
priority could not be set. This might be of use in case something
(selinux, old kernel, etc.) does not allow the requested scheduling
priority to be set.

This could be to some extend done as follows:

	ionice -c3 command || command

but the downside is that one could not really tell if what failed was
setting priority or command itself, which could result in duplicate
command run.

This patch solves the situation, so that user can do

	ionice -t -c3 command

Addresses-Red-Hat-Bugzilla: #443842
Signed-off-by: Lubomir Kundrak <lkundrak@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/schedutils/ionice.1 b/schedutils/ionice.1
index 93aabe827c0c01a75163c1dd71afa650e6990a9f..a17dd4f44a5eebe558c7e1153a0fb35c7f6ec3ea 100644 (file)
--- a/schedutils/ionice.1
+++ b/schedutils/ionice.1
@@ -50,6 +50,11 @@ data.
 Pass in a process pid to change an already running process. If this argument
 is not given, \fBionice\fP will run the listed program with the given
 parameters.
+.TP 7
+\fB-t\fP
+Ignore failure to set requested priority. If COMMAND is specified, run it
+even in case it was not possible to set desired scheduling priority, what
+can happen due to insufficient privilegies or old kernel version.
 
 .SH EXAMPLES
 .LP

diff --git a/schedutils/ionice.c b/schedutils/ionice.c
index 679014af42907a9ea84c2cc9031fceede7a134ec..f5c02db5e3ba9230b3a88cf5fee8705cc01948b6 100644 (file)
--- a/schedutils/ionice.c
+++ b/schedutils/ionice.c
@@ -50,16 +50,17 @@ static void usage(void)
        printf("\t-c\tScheduling class\n");
        printf("\t\t\t1: realtime, 2: best-effort, 3: idle\n");
        printf("\t-p\tProcess pid\n");
+       printf("\t-t\tIgnore failures to set priority, run command unconditionally\n");
        printf("\t-h\tThis help page\n");
        printf("\nJens Axboe <axboe@suse.de> (C) 2005\n");
 }
 
 int main(int argc, char *argv[])
 {
-       int ioprio = 4, set = 0, ioprio_class = IOPRIO_CLASS_BE;
+       int ioprio = 4, set = 0, tolerant = 0, ioprio_class = IOPRIO_CLASS_BE;
        int c, pid = 0;
 
-       while ((c = getopt(argc, argv, "+n:c:p:h")) != EOF) {
+       while ((c = getopt(argc, argv, "+n:c:p:th")) != EOF) {
                switch (c) {
                case 'n':
                        ioprio = strtol(optarg, NULL, 10);
@@ -72,6 +73,9 @@ int main(int argc, char *argv[])
                case 'p':
                        pid = strtol(optarg, NULL, 10);
                        break;
+               case 't':
+                       tolerant = 1;
+                       break;
                case 'h':
                default:
                        usage();
@@ -115,8 +119,10 @@ int main(int argc, char *argv[])
                }
        } else {
                if (ioprio_set(IOPRIO_WHO_PROCESS, pid, ioprio | ioprio_class << IOPRIO_CLASS_SHIFT) == -1) {
-                       perror("ioprio_set");
-                       exit(EXIT_FAILURE);
+                       if (!tolerant) {
+                               perror("ioprio_set");
+                               exit(EXIT_FAILURE);
+                       }
                }
 
                if (argv[optind]) {