Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ca768b66 authored by Stefan Weinhuber's avatar Stefan Weinhuber Committed by Martin Schwidefsky
Browse files

[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: default avatarStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 16d2ce27

drivers/s390/char/vmlogrdr.c

+24 −12
Original line number Diff line number Diff line
@@ -249,9 +249,7 @@ static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr, 
	char cp_command[80];

	char cp_response[160];

	char *onoff, *qid_string;



	memset(cp_command, 0x00, sizeof(cp_command));

	memset(cp_response, 0x00, sizeof(cp_response));

	int rc;



	onoff = ((action == 1) ? "ON" : "OFF");

	qid_string = ((recording_class_AB == 1) ? " QID * " : "");
@@ -263,13 +261,13 @@ static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr, 
	 * 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);

	}
@@ -279,7 +277,6 @@ 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
@@ -288,10 +285,25 @@ static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr, 
	 * '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;

}