From ca768b663131ca644689fcadc9ca092dcc96a758 Mon Sep 17 00:00:00 2001 From: Stefan Weinhuber Date: Wed, 10 Nov 2010 10:05:54 +0100 Subject: [PATCH] [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 Signed-off-by: Martin Schwidefsky --- drivers/s390/char/vmlogrdr.c | 36 ++++++++++++++++++++++++------------ 1 file 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; } -- 2.11.0