diff options
Diffstat (limited to 'Documentation/s390/CommonIO')
| -rw-r--r-- | Documentation/s390/CommonIO | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/Documentation/s390/CommonIO b/Documentation/s390/CommonIO index a831d9ae5a5e..59d1166d41ee 100644 --- a/Documentation/s390/CommonIO +++ b/Documentation/s390/CommonIO @@ -30,7 +30,7 @@ Command line parameters device numbers (0xabcd or abcd, for 2.4 backward compatibility). You can use the 'all' keyword to ignore all devices. The '!' operator will cause the I/O-layer to _not_ ignore a device. - The order on the command line is not important. + The command line is parsed from left to right. For example, cio_ignore=0.0.0023-0.0.0042,0.0.4711 @@ -72,13 +72,14 @@ Command line parameters /proc/cio_ignore; "add <device range>, <device range>, ..." will ignore the specified devices. - Note: Already known devices cannot be ignored. + Note: While already known devices can be added to the list of devices to be + ignored, there will be no effect on then. However, if such a device + disappears and then reappeares, it will then be ignored. - For example, if device 0.0.abcd is already known and all other devices - 0.0.a000-0.0.afff are not known, + For example, "echo add 0.0.a000-0.0.accc, 0.0.af00-0.0.afff > /proc/cio_ignore" - will add 0.0.a000-0.0.abcc, 0.0.abce-0.0.accc and 0.0.af00-0.0.afff to the - list of ignored devices and skip 0.0.abcd. + will add 0.0.a000-0.0.accc and 0.0.af00-0.0.afff to the list of ignored + devices. The devices can be specified either by bus id (0.0.abcd) or, for 2.4 backward compatibilty, by the device number in hexadecimal (0xabcd or abcd). @@ -98,7 +99,8 @@ Command line parameters - /proc/s390dbf/cio_trace/hex_ascii Logs the calling of functions in the common I/O-layer and, if applicable, - which subchannel they were called for. + which subchannel they were called for, as well as dumps of some data + structures (like irb in an error case). The level of logging can be changed to be more or less verbose by piping to /proc/s390dbf/cio_*/level a number between 0 and 6; see the documentation on |