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authorStefan Weinhuber <wein@de.ibm.com>2010-11-10 12:05:54 +0300
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-11-10 12:05:54 +0300
commitca768b663131ca644689fcadc9ca092dcc96a758 (patch)
treeaaf4136000d7f0204830978f304636beb4fd2368 /drivers/s390/char
parent16d2ce271c6b8b3527ed1461d03b5f373d53f78f (diff)
downloadlinux-ca768b663131ca644689fcadc9ca092dcc96a758.tar.xz
[S390] vmlogrdr: purge after recording is switched off
If automatic purge is enabled for a vmlogrdr device, old records are purged before an IUCV recording service is switched on or off. If z/VM generates a large number of records between purging and switching the recording service off, these records remain queued, and may have a negative performance impact on the z/VM system. To avoid this problem, we need to purge the records after recording is switched off. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/char')
-rw-r--r--drivers/s390/char/vmlogrdr.c36
1 files changed, 24 insertions, 12 deletions
diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c
index 9f661426e4a1..1cc726b98ec8 100644
--- a/drivers/s390/char/vmlogrdr.c
+++ b/drivers/s390/char/vmlogrdr.c
@@ -249,27 +249,25 @@ static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr,
char cp_command[80];
char cp_response[160];
char *onoff, *qid_string;
+ int rc;
- memset(cp_command, 0x00, sizeof(cp_command));
- memset(cp_response, 0x00, sizeof(cp_response));
-
- onoff = ((action == 1) ? "ON" : "OFF");
+ onoff = ((action == 1) ? "ON" : "OFF");
qid_string = ((recording_class_AB == 1) ? " QID * " : "");
- /*
+ /*
* The recording commands needs to be called with option QID
* for guests that have previlege classes A or B.
* Purging has to be done as separate step, because recording
* can't be switched on as long as records are on the queue.
* Doing both at the same time doesn't work.
*/
-
- if (purge) {
+ if (purge && (action == 1)) {
+ memset(cp_command, 0x00, sizeof(cp_command));
+ memset(cp_response, 0x00, sizeof(cp_response));
snprintf(cp_command, sizeof(cp_command),
"RECORDING %s PURGE %s",
logptr->recording_name,
qid_string);
-
cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
}
@@ -279,19 +277,33 @@ static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr,
logptr->recording_name,
onoff,
qid_string);
-
cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
/* The recording command will usually answer with 'Command complete'
* on success, but when the specific service was never connected
* before then there might be an additional informational message
* 'HCPCRC8072I Recording entry not found' before the
- * 'Command complete'. So I use strstr rather then the strncmp.
+ * 'Command complete'. So I use strstr rather then the strncmp.
*/
if (strstr(cp_response,"Command complete"))
- return 0;
+ rc = 0;
else
- return -EIO;
+ rc = -EIO;
+ /*
+ * If we turn recording off, we have to purge any remaining records
+ * afterwards, as a large number of queued records may impact z/VM
+ * performance.
+ */
+ if (purge && (action == 0)) {
+ memset(cp_command, 0x00, sizeof(cp_command));
+ memset(cp_response, 0x00, sizeof(cp_response));
+ snprintf(cp_command, sizeof(cp_command),
+ "RECORDING %s PURGE %s",
+ logptr->recording_name,
+ qid_string);
+ cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
+ }
+ return rc;
}