From d410ad416617dd759436028e1cb0f545fe5f5d07 Mon Sep 17 00:00:00 2001 From: jhb Date: Fri, 26 Oct 2001 06:09:01 +0000 Subject: Use msleep() to avoid lost wakeup's instead of doing an ineffective splhigh() before the mtx_unlock and tsleep(). The splhigh() was probably correct in the original code using simplelocks but is not correct in 5.0-current. Noticed by: Andrew Reiter --- sys/kern/subr_rman.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) (limited to 'sys/kern/subr_rman.c') diff --git a/sys/kern/subr_rman.c b/sys/kern/subr_rman.c index 1fbafd3..67791c2 100644 --- a/sys/kern/subr_rman.c +++ b/sys/kern/subr_rman.c @@ -426,35 +426,25 @@ rman_activate_resource(struct resource *r) int rman_await_resource(struct resource *r, int pri, int timo) { - int rv, s; + int rv; struct resource *whohas; struct rman *rm; rm = r->r_rm; + mtx_lock(rm->rm_mtx); for (;;) { - mtx_lock(rm->rm_mtx); rv = int_rman_activate_resource(rm, r, &whohas); if (rv != EBUSY) return (rv); /* returns with mutex held */ if (r->r_sharehead == 0) panic("rman_await_resource"); - /* - * splhigh hopefully will prevent a race between - * mtx_unlock and tsleep where a process - * could conceivably get in and release the resource - * before we have a chance to sleep on it. - */ - s = splhigh(); whohas->r_flags |= RF_WANTED; - mtx_unlock(rm->rm_mtx); - rv = tsleep(r->r_sharehead, pri, "rmwait", timo); + rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo); if (rv) { - splx(s); - return rv; + mtx_unlock(rm->rm_mtx); + return (rv); } - mtx_lock(rm->rm_mtx); - splx(s); } } -- cgit v1.1