config OVERLAY_FS
tristate "Overlay filesystem support"
help
An overlay filesystem combines two filesystems - an 'upper' filesystem
and a 'lower' filesystem. When a name exists in both filesystems, the
object in the 'upper' filesystem is visible while the object in the
'lower' filesystem is either hidden or, in the case of directories,
merged with the 'upper' object.
For more information see Documentation/filesystems/overlayfs.txt
config OVERLAY_FS_REDIRECT_DIR
bool "Overlayfs: turn on redirect dir feature by default"
depends on OVERLAY_FS
help
If this config option is enabled then overlay filesystems will use
redirects when renaming directories by default. In this case it is
still possible to turn off redirects globally with the
"redirect_dir=off" module option or on a filesystem instance basis
with the "redirect_dir=off" mount option.
Note, that redirects are not backward compatible. That is, mounting
an overlay which has redirects on a kernel that doesn't support this
feature will have unexpected results.
value='master' selected='selected'>master
perf trace: Beautify sched_[gs]et_attr return value
Both return errno, show the string associated then.
More work needed to capture the sched_attr arg to beautify it in turn,
probably using BPF.
Before:
0.210 ( 0.001 ms): sched_setattr(uattr: 0x7ffc684f02b0) = -22
After the patch, for this sched_attr, all other parms are zero, so not
shown:
struct sched_attr attr = {
.size = sizeof(attr),
.sched_policy = SCHED_DEADLINE,
.sched_runtime = 10 * USECS_PER_SEC,
.sched_period = 30 * USECS_PER_SEC,
.sched_deadline = attr.sched_period,
};
0.321 ( 0.002 ms): sched_setattr(uattr: 0x7ffc44116da0) = -1 EINVAL Invalid argument
[root@jouet c]# perf trace -e sched_setattr ./sched_deadline
Couldn't negotiate deadline: Invalid argument
0.229 ( 0.003 ms): sched_setattr(uattr: 0x7ffd8dcd8df0) = -1 EINVAL Invalid argument
[root@jouet c]#
Now to figure out the reason for this EINVAL.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-tyot2n7e48zm8pdw8tbcm3sl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>