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author | Stefan Weinhuber <wein@de.ibm.com> | 2010-11-10 09:05:54 (GMT) |
---|---|---|
committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2010-11-10 09:05:54 (GMT) |
commit | ca768b663131ca644689fcadc9ca092dcc96a758 (patch) | |
tree | aaf4136000d7f0204830978f304636beb4fd2368 /drivers/s390/char/vmlogrdr.c | |
parent | 16d2ce271c6b8b3527ed1461d03b5f373d53f78f (diff) | |
download | linux-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/vmlogrdr.c')
-rw-r--r-- | drivers/s390/char/vmlogrdr.c | 36 |
1 files changed, 24 insertions, 12 deletions
diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c index 9f66142..1cc726b 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; } |