[src/trunk]: src/sys Set LW_SINTR earlier so it doesn't pose a problem for do...

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details:   https://anonhg.NetBSD.org/src/rev/135fb2c8db6f
branches:  trunk
changeset: 1009298:135fb2c8db6f
user:      ad <ad%NetBSD.org@localhost>
date:      Sun Apr 19 20:35:29 2020 +0000

description:
Set LW_SINTR earlier so it doesn't pose a problem for doing interruptable
waits with turnstiles (not currently done).

diffstat:

 sys/kern/kern_condvar.c   |  16 ++++++++--------
 sys/kern/kern_sleepq.c    |  23 +++++++++++++++--------
 sys/kern/kern_synch.c     |  18 +++++++++++-------
 sys/kern/kern_timeout.c   |   6 +++---
 sys/kern/kern_turnstile.c |   6 +++---
 sys/kern/sys_lwp.c        |   6 +++---
 sys/kern/sys_select.c     |   6 +++---
 sys/sys/sleepq.h          |   5 +++--
 8 files changed, 49 insertions(+), 37 deletions(-)

diffs (truncated from 344 to 300 lines):

diff -r 4839670fd48f -r 135fb2c8db6f sys/kern/kern_condvar.c
--- a/sys/kern/kern_condvar.c   Sun Apr 19 20:31:59 2020 +0000
+++ b/sys/kern/kern_condvar.c   Sun Apr 19 20:35:29 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_condvar.c,v 1.46 2020/04/13 15:54:45 maxv Exp $   */
+/*     $NetBSD: kern_condvar.c,v 1.47 2020/04/19 20:35:29 ad Exp $     */
 
 /*-
  * Copyright (c) 2006, 2007, 2008, 2019, 2020 The NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_condvar.c,v 1.46 2020/04/13 15:54:45 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_condvar.c,v 1.47 2020/04/19 20:35:29 ad Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -116,7 +116,7 @@
  *     condition variable, and increment the number of waiters.
  */
 static inline void
-cv_enter(kcondvar_t *cv, kmutex_t *mtx, lwp_t *l)
+cv_enter(kcondvar_t *cv, kmutex_t *mtx, lwp_t *l, bool catch_p)
 {
        sleepq_t *sq;
        kmutex_t *mp;
@@ -129,7 +129,7 @@
        mp = sleepq_hashlock(cv);
        sq = CV_SLEEPQ(cv);
        sleepq_enter(sq, l, mp);
-       sleepq_enqueue(sq, cv, CV_WMESG(cv), &cv_syncobj);
+       sleepq_enqueue(sq, cv, CV_WMESG(cv), &cv_syncobj, catch_p);
        mutex_exit(mtx);
        KASSERT(cv_has_waiters(cv));
 }
@@ -169,7 +169,7 @@
 
        KASSERT(mutex_owned(mtx));
 
-       cv_enter(cv, mtx, l);
+       cv_enter(cv, mtx, l, false);
        (void)sleepq_block(0, false);
        mutex_enter(mtx);
 }
@@ -190,7 +190,7 @@
 
        KASSERT(mutex_owned(mtx));
 
-       cv_enter(cv, mtx, l);
+       cv_enter(cv, mtx, l, true);
        error = sleepq_block(0, true);
        mutex_enter(mtx);
        return error;
@@ -213,7 +213,7 @@
 
        KASSERT(mutex_owned(mtx));
 
-       cv_enter(cv, mtx, l);
+       cv_enter(cv, mtx, l, false);
        error = sleepq_block(timo, false);
        mutex_enter(mtx);
        return error;
@@ -238,7 +238,7 @@
 
        KASSERT(mutex_owned(mtx));
 
-       cv_enter(cv, mtx, l);
+       cv_enter(cv, mtx, l, true);
        error = sleepq_block(timo, true);
        mutex_enter(mtx);
        return error;
diff -r 4839670fd48f -r 135fb2c8db6f sys/kern/kern_sleepq.c
--- a/sys/kern/kern_sleepq.c    Sun Apr 19 20:31:59 2020 +0000
+++ b/sys/kern/kern_sleepq.c    Sun Apr 19 20:35:29 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_sleepq.c,v 1.65 2020/04/13 15:54:45 maxv Exp $    */
+/*     $NetBSD: kern_sleepq.c,v 1.66 2020/04/19 20:35:29 ad Exp $      */
 
 /*-
  * Copyright (c) 2006, 2007, 2008, 2009, 2019, 2020 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_sleepq.c,v 1.65 2020/04/13 15:54:45 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_sleepq.c,v 1.66 2020/04/19 20:35:29 ad Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -210,13 +210,15 @@
  *     lock) must have be released (see sleeptab_lookup(), sleepq_enter()).
  */
 void
-sleepq_enqueue(sleepq_t *sq, wchan_t wchan, const char *wmesg, syncobj_t *sobj)
+sleepq_enqueue(sleepq_t *sq, wchan_t wchan, const char *wmesg, syncobj_t *sobj,
+    bool catch_p)
 {
        lwp_t *l = curlwp;
 
        KASSERT(lwp_locked(l, NULL));
        KASSERT(l->l_stat == LSONPROC);
        KASSERT(l->l_wchan == NULL && l->l_sleepq == NULL);
+       KASSERT((l->l_flag & LW_SINTR) == 0);
 
        l->l_syncobj = sobj;
        l->l_wchan = wchan;
@@ -224,6 +226,8 @@
        l->l_wmesg = wmesg;
        l->l_slptime = 0;
        l->l_stat = LSSLEEP;
+       if (catch_p)
+               l->l_flag |= LW_SINTR;
 
        sleepq_insert(sq, l, sobj);
 
@@ -254,13 +258,9 @@
 
        /*
         * If sleeping interruptably, check for pending signals, exits or
-        * core dump events.  XXX The set of LW_SINTR here assumes no unlock
-        * between sleepq_enqueue() and sleepq_block().  Unlock between
-        * those only happens with turnstiles, which never set catch_p. 
-        * Ugly but safe.
+        * core dump events.
         */
        if (catch_p) {
-               l->l_flag |= LW_SINTR;
                if ((l->l_flag & (LW_CANCELLED|LW_WEXIT|LW_WCORE)) != 0) {
                        l->l_flag &= ~LW_CANCELLED;
                        error = EINTR;
@@ -273,6 +273,13 @@
                /* lwp_unsleep() will release the lock */
                lwp_unsleep(l, true);
        } else {
+               /*
+                * The LWP may have already been awoken if the caller
+                * dropped the sleep queue lock between sleepq_enqueue() and
+                * sleepq_block().  If that happends l_stat will be LSONPROC
+                * and mi_switch() will treat this as a preemption.  No need
+                * to do anything special here.
+                */
                if (timo) {
                        l->l_flag &= ~LW_STIMO;
                        callout_schedule(&l->l_timeout_ch, timo);
diff -r 4839670fd48f -r 135fb2c8db6f sys/kern/kern_synch.c
--- a/sys/kern/kern_synch.c     Sun Apr 19 20:31:59 2020 +0000
+++ b/sys/kern/kern_synch.c     Sun Apr 19 20:35:29 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_synch.c,v 1.346 2020/04/04 20:21:53 ad Exp $      */
+/*     $NetBSD: kern_synch.c,v 1.347 2020/04/19 20:35:29 ad Exp $      */
 
 /*-
  * Copyright (c) 1999, 2000, 2004, 2006, 2007, 2008, 2009, 2019, 2020
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.346 2020/04/04 20:21:53 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.347 2020/04/19 20:35:29 ad Exp $");
 
 #include "opt_kstack.h"
 #include "opt_dtrace.h"
@@ -173,6 +173,7 @@
        struct lwp *l = curlwp;
        sleepq_t *sq;
        kmutex_t *mp;
+       bool catch_p;
 
        KASSERT((l->l_pflag & LP_INTR) == 0);
        KASSERT(ident != &lbolt);
@@ -183,10 +184,11 @@
        }
 
        l->l_kpriority = true;
+       catch_p = priority & PCATCH;
        sq = sleeptab_lookup(&sleeptab, ident, &mp);
        sleepq_enter(sq, l, mp);
-       sleepq_enqueue(sq, ident, wmesg, &sleep_syncobj);
-       return sleepq_block(timo, priority & PCATCH);
+       sleepq_enqueue(sq, ident, wmesg, &sleep_syncobj, catch_p);
+       return sleepq_block(timo, catch_p);
 }
 
 int
@@ -196,6 +198,7 @@
        struct lwp *l = curlwp;
        sleepq_t *sq;
        kmutex_t *mp;
+       bool catch_p;
        int error;
 
        KASSERT((l->l_pflag & LP_INTR) == 0);
@@ -207,11 +210,12 @@
        }
 
        l->l_kpriority = true;
+       catch_p = priority & PCATCH;
        sq = sleeptab_lookup(&sleeptab, ident, &mp);
        sleepq_enter(sq, l, mp);
-       sleepq_enqueue(sq, ident, wmesg, &sleep_syncobj);
+       sleepq_enqueue(sq, ident, wmesg, &sleep_syncobj, catch_p);
        mutex_exit(mtx);
-       error = sleepq_block(timo, priority & PCATCH);
+       error = sleepq_block(timo, catch_p);
 
        if ((priority & PNORELOCK) == 0)
                mutex_enter(mtx);
@@ -238,7 +242,7 @@
        l->l_kpriority = true;
        lwp_lock(l);
        KERNEL_UNLOCK_ALL(NULL, &l->l_biglocks);
-       sleepq_enqueue(NULL, l, wmesg, &kpause_syncobj);
+       sleepq_enqueue(NULL, l, wmesg, &kpause_syncobj, intr);
        error = sleepq_block(timo, intr);
        if (mtx != NULL)
                mutex_enter(mtx);
diff -r 4839670fd48f -r 135fb2c8db6f sys/kern/kern_timeout.c
--- a/sys/kern/kern_timeout.c   Sun Apr 19 20:31:59 2020 +0000
+++ b/sys/kern/kern_timeout.c   Sun Apr 19 20:35:29 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_timeout.c,v 1.60 2020/04/13 15:54:45 maxv Exp $   */
+/*     $NetBSD: kern_timeout.c,v 1.61 2020/04/19 20:35:29 ad Exp $     */
 
 /*-
  * Copyright (c) 2003, 2006, 2007, 2008, 2009, 2019 The NetBSD Foundation, Inc.
@@ -59,7 +59,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_timeout.c,v 1.60 2020/04/13 15:54:45 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_timeout.c,v 1.61 2020/04/19 20:35:29 ad Exp $");
 
 /*
  * Timeouts are kept in a hierarchical timing wheel.  The c_time is the
@@ -539,7 +539,7 @@
                        l->l_kpriority = true;
                        sleepq_enter(&cc->cc_sleepq, l, cc->cc_lock);
                        sleepq_enqueue(&cc->cc_sleepq, cc, "callout",
-                           &sleep_syncobj);
+                           &sleep_syncobj, false);
                        sleepq_block(0, false);
                }
 
diff -r 4839670fd48f -r 135fb2c8db6f sys/kern/kern_turnstile.c
--- a/sys/kern/kern_turnstile.c Sun Apr 19 20:31:59 2020 +0000
+++ b/sys/kern/kern_turnstile.c Sun Apr 19 20:35:29 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_turnstile.c,v 1.38 2020/03/26 22:43:19 ad Exp $   */
+/*     $NetBSD: kern_turnstile.c,v 1.39 2020/04/19 20:35:29 ad Exp $   */
 
 /*-
  * Copyright (c) 2002, 2006, 2007, 2009, 2019, 2020
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_turnstile.c,v 1.38 2020/03/26 22:43:19 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_turnstile.c,v 1.39 2020/04/19 20:35:29 ad Exp $");
 
 #include <sys/param.h>
 #include <sys/lockdebug.h>
@@ -429,7 +429,7 @@
        obase = l->l_kpribase;
        if (obase < PRI_KTHREAD)
                l->l_kpribase = PRI_KTHREAD;
-       sleepq_enqueue(sq, obj, "tstile", sobj);
+       sleepq_enqueue(sq, obj, "tstile", sobj, false);
 
        /*
         * Disable preemption across this entire block, as we may drop
diff -r 4839670fd48f -r 135fb2c8db6f sys/kern/sys_lwp.c
--- a/sys/kern/sys_lwp.c        Sun Apr 19 20:31:59 2020 +0000
+++ b/sys/kern/sys_lwp.c        Sun Apr 19 20:35:29 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_lwp.c,v 1.76 2020/04/04 20:20:12 thorpej Exp $     */
+/*     $NetBSD: sys_lwp.c,v 1.77 2020/04/19 20:35:29 ad Exp $  */
 
 /*-
  * Copyright (c) 2001, 2006, 2007, 2008, 2019, 2020 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_lwp.c,v 1.76 2020/04/04 20:20:12 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_lwp.c,v 1.77 2020/04/19 20:35:29 ad Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -542,7 +542,7 @@
                return EALREADY;
        }
        l->l_biglocks = 0;
-       sleepq_enqueue(NULL, l, "parked", &lwp_park_syncobj);
+       sleepq_enqueue(NULL, l, "parked", &lwp_park_syncobj, true);
        error = sleepq_block(timo, true);
        switch (error) {
        case EWOULDBLOCK:
diff -r 4839670fd48f -r 135fb2c8db6f sys/kern/sys_select.c
--- a/sys/kern/sys_select.c     Sun Apr 19 20:31:59 2020 +0000