Add cv_wait_io() to account I/O time

Under Linux when a task is waiting on I/O it should call the
io_schedule() function for proper accounting.  The Solaris
cv_wait() function provides no way to specify what the cv
is waiting on therefore cv_wait_io() is introduced.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #206

diff --git a/include/sys/condvar.h b/include/sys/condvar.h
index 709a86d3900aca3afa6798f45680105ec86dd020..62210357d438abe873ff66aff482b090ae2380f1 100644 (file)
--- a/include/sys/condvar.h
+++ b/include/sys/condvar.h
@@ -51,6 +51,7 @@ typedef enum { CV_DEFAULT=0, CV_DRIVER } kcv_type_t;
 extern void __cv_init(kcondvar_t *cvp, char *name, kcv_type_t type, void *arg);
 extern void __cv_destroy(kcondvar_t *cvp);
 extern void __cv_wait(kcondvar_t *cvp, kmutex_t *mp);
+extern void __cv_wait_io(kcondvar_t *cvp, kmutex_t *mp);
 extern void __cv_wait_interruptible(kcondvar_t *cvp, kmutex_t *mp);
 extern clock_t __cv_timedwait(kcondvar_t *cvp, kmutex_t *mp, clock_t exp_time);
 extern clock_t __cv_timedwait_interruptible(kcondvar_t *cvp, kmutex_t *mp,
@@ -61,6 +62,7 @@ extern void __cv_broadcast(kcondvar_t *cvp);
 #define cv_init(cvp, name, type, arg)          __cv_init(cvp, name, type, arg)
 #define cv_destroy(cvp)                                __cv_destroy(cvp)
 #define cv_wait(cvp, mp)                       __cv_wait(cvp, mp)
+#define cv_wait_io(cvp, mp)                    __cv_wait_io(cvp, mp)
 #define cv_wait_interruptible(cvp, mp)         __cv_wait_interruptible(cvp,mp)
 #define cv_timedwait(cvp, mp, t)               __cv_timedwait(cvp, mp, t)
 #define cv_timedwait_interruptible(cvp, mp, t)                                \

diff --git a/module/spl/spl-condvar.c b/module/spl/spl-condvar.c
index 6ed6579b308272e0ecd1836f851547b38df04504..fefe98598a13ce24037cf5a5a6b6c2b1621432a8 100644 (file)
--- a/module/spl/spl-condvar.c
+++ b/module/spl/spl-condvar.c
@@ -97,7 +97,7 @@ __cv_destroy(kcondvar_t *cvp)
 EXPORT_SYMBOL(__cv_destroy);
 
 static void
-cv_wait_common(kcondvar_t *cvp, kmutex_t *mp, int state)
+cv_wait_common(kcondvar_t *cvp, kmutex_t *mp, int state, int io)
 {
        DEFINE_WAIT(wait);
        SENTRY;
@@ -121,7 +121,10 @@ cv_wait_common(kcondvar_t *cvp, kmutex_t *mp, int state)
         * ensures we're linked in to the waiters list and avoids the
         * race where 'cvp->cv_waiters > 0' but the list is empty. */
        mutex_exit(mp);
-       schedule();
+       if (io)
+               io_schedule();
+       else
+               schedule();
        mutex_enter(mp);
 
        /* No more waiters a different mutex could be used */
@@ -139,17 +142,24 @@ cv_wait_common(kcondvar_t *cvp, kmutex_t *mp, int state)
 void
 __cv_wait(kcondvar_t *cvp, kmutex_t *mp)
 {
-       cv_wait_common(cvp, mp, TASK_UNINTERRUPTIBLE);
+       cv_wait_common(cvp, mp, TASK_UNINTERRUPTIBLE, 0);
 }
 EXPORT_SYMBOL(__cv_wait);
 
 void
 __cv_wait_interruptible(kcondvar_t *cvp, kmutex_t *mp)
 {
-       cv_wait_common(cvp, mp, TASK_INTERRUPTIBLE);
+       cv_wait_common(cvp, mp, TASK_INTERRUPTIBLE, 0);
 }
 EXPORT_SYMBOL(__cv_wait_interruptible);
 
+void
+__cv_wait_io(kcondvar_t *cvp, kmutex_t *mp)
+{
+       cv_wait_common(cvp, mp, TASK_UNINTERRUPTIBLE, 1);
+}
+EXPORT_SYMBOL(__cv_wait_io);
+
 /* 'expire_time' argument is an absolute wall clock time in jiffies.
  * Return value is time left (expire_time - now) or -1 if timeout occurred.
  */