diff options
Diffstat (limited to 'usr')
| -rw-r--r-- | usr/src/uts/common/io/devpoll.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/usr/src/uts/common/io/devpoll.c b/usr/src/uts/common/io/devpoll.c index 1e71013d17..3c31040c6a 100644 --- a/usr/src/uts/common/io/devpoll.c +++ b/usr/src/uts/common/io/devpoll.c @@ -19,7 +19,7 @@ * CDDL HEADER END */ /* - * Copyright 2007 Sun Microsystems, Inc. All rights reserved. + * Copyright 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ @@ -107,7 +107,7 @@ static struct dev_ops dp_ops = { static struct modldrv modldrv = { &mod_driverops, /* type of module - a driver */ - "Dev Poll driver %I%", + "/dev/poll driver", &dp_ops, }; @@ -293,6 +293,7 @@ retry: start = fd + 1; } pdp = pcache_lookup_fd(pcp, fd); +repoll: ASSERT(pdp != NULL); ASSERT(pdp->pd_fd == fd); if (pdp->pd_fp == NULL) { @@ -394,6 +395,12 @@ retry: if (pdp->pd_php == NULL) { pollhead_insert(php, pdp); pdp->pd_php = php; + /* + * An event of interest may have + * arrived between the VOP_POLL() and + * the pollhead_insert(); check again. + */ + goto repoll; } } } else { @@ -626,12 +633,11 @@ dpwrite(dev_t dev, struct uio *uiop, cred_t *credp) &pfdp->revents, &php, NULL); curthread->t_pollcache = NULL; /* - * We always set the bit when this fd is cached. - * So we don't have to worry about missing a - * pollwakeup between VOP_POLL and pollhead_insert. - * This forces the first DP_POLL to poll this fd. + * We always set the bit when this fd is cached; + * this forces the first DP_POLL to poll this fd. * Real performance gain comes from subsequent - * DP_POLL. + * DP_POLL. We also attempt a pollhead_insert(); + * if it's not possible, we'll do it in dpioctl(). */ BT_SET(pcp->pc_bitmap, fd); if (error != 0) { @@ -815,7 +821,7 @@ dpioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *credp, int *rvalp) if (time_out == 0) /* immediate timeout */ break; rval = cv_waituntil_sig(&pcp->pc_cv, &pcp->pc_lock, - rqtp, timecheck); + rqtp, timecheck); /* * If we were awakened by a signal or timeout * then break the loop, else poll again. |