From d87af216e03890b85bd5e65ced5753c1cc08d705 Mon Sep 17 00:00:00 2001 From: mjacob Date: Thu, 2 Nov 2006 21:12:37 +0000 Subject: Add a tunable that allows one to turn off the automatic sending of the ORDERED tag. This recoups significant performance gains for many arrays. The default is still to send out the ORDERED tag periodically. Reviewed by: scsi (justin+timeout) --- sys/cam/scsi/scsi_da.c | 42 ++++++++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 16 deletions(-) (limited to 'sys/cam') diff --git a/sys/cam/scsi/scsi_da.c b/sys/cam/scsi/scsi_da.c index fc3692b..284767a 100644 --- a/sys/cam/scsi/scsi_da.c +++ b/sys/cam/scsi/scsi_da.c @@ -491,8 +491,14 @@ static void dashutdown(void *arg, int howto); #define DA_DEFAULT_RETRY 4 #endif +#ifndef DA_DEFAULT_SEND_ORDERED +#define DA_DEFAULT_SEND_ORDERED 1 +#endif + + static int da_retry_count = DA_DEFAULT_RETRY; static int da_default_timeout = DA_DEFAULT_TIMEOUT; +static int da_send_ordered = DA_DEFAULT_SEND_ORDERED; SYSCTL_NODE(_kern_cam, OID_AUTO, da, CTLFLAG_RD, 0, "CAM Direct Access Disk driver"); @@ -502,6 +508,9 @@ TUNABLE_INT("kern.cam.da.retry_count", &da_retry_count); SYSCTL_INT(_kern_cam_da, OID_AUTO, default_timeout, CTLFLAG_RW, &da_default_timeout, 0, "Normal I/O timeout (in seconds)"); TUNABLE_INT("kern.cam.da.default_timeout", &da_default_timeout); +SYSCTL_INT(_kern_cam_da, OID_AUTO, da_send_ordered, CTLFLAG_RW, + &da_send_ordered, 0, "Send Ordered Tags"); +TUNABLE_INT("kern.cam.da.da_send_ordered", &da_send_ordered); /* * DA_ORDEREDTAG_INTERVAL determines how often, relative @@ -851,7 +860,7 @@ dainit(void) if (status != CAM_REQ_CMP) { printf("da: Failed to attach master async callback " "due to status 0x%x!\n", status); - } else { + } else if (da_send_ordered) { /* * Schedule a periodic event to occasionally send an @@ -1938,24 +1947,25 @@ dasendorderedtag(void *arg) { struct da_softc *softc; int s; + if (da_send_ordered) { + for (softc = SLIST_FIRST(&softc_list); + softc != NULL; + softc = SLIST_NEXT(softc, links)) { + s = splsoftcam(); + if ((softc->ordered_tag_count == 0) + && ((softc->flags & DA_FLAG_WENT_IDLE) == 0)) { + softc->flags |= DA_FLAG_NEED_OTAG; + } + if (softc->outstanding_cmds > 0) + softc->flags &= ~DA_FLAG_WENT_IDLE; - for (softc = SLIST_FIRST(&softc_list); - softc != NULL; - softc = SLIST_NEXT(softc, links)) { - s = splsoftcam(); - if ((softc->ordered_tag_count == 0) - && ((softc->flags & DA_FLAG_WENT_IDLE) == 0)) { - softc->flags |= DA_FLAG_NEED_OTAG; + softc->ordered_tag_count = 0; + splx(s); } - if (softc->outstanding_cmds > 0) - softc->flags &= ~DA_FLAG_WENT_IDLE; - - softc->ordered_tag_count = 0; - splx(s); + /* Queue us up again */ + timeout(dasendorderedtag, NULL, + (da_default_timeout * hz) / DA_ORDEREDTAG_INTERVAL); } - /* Queue us up again */ - timeout(dasendorderedtag, NULL, - (da_default_timeout * hz) / DA_ORDEREDTAG_INTERVAL); } /* -- cgit v1.1