[src/trunk]: src/sys/kern - lwp_wait(): if the process is exiting and no prog...

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details:   https://anonhg.NetBSD.org/src/rev/77276979dafe
branches:  trunk
changeset: 1006794:77276979dafe
user:      ad <ad%NetBSD.org@localhost>
date:      Mon Jan 27 21:58:16 2020 +0000

description:
- lwp_wait(): if the process is exiting and no progress is being made, wake
  every clock tick and kick all the LWPs again.

- lwp_create(): copy the LW_WEXIT etc flags while holding the parent's
  p_lock.  Copy only LW_WREBOOT in the case of fork(), since a pending
  coredump or exit() in the parent process isn't for the child.

diffstat:

 sys/kern/kern_lwp.c |  17 +++++++++--------
 1 files changed, 9 insertions(+), 8 deletions(-)

diffs (59 lines):

diff -r 3cad0ffddc68 -r 77276979dafe sys/kern/kern_lwp.c
--- a/sys/kern/kern_lwp.c       Mon Jan 27 21:30:17 2020 +0000
+++ b/sys/kern/kern_lwp.c       Mon Jan 27 21:58:16 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_lwp.c,v 1.221 2020/01/26 19:06:24 ad Exp $        */
+/*     $NetBSD: kern_lwp.c,v 1.222 2020/01/27 21:58:16 ad Exp $        */
 
 /*-
  * Copyright (c) 2001, 2006, 2007, 2008, 2009, 2019, 2020
@@ -211,7 +211,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.221 2020/01/26 19:06:24 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.222 2020/01/27 21:58:16 ad Exp $");
 
 #include "opt_ddb.h"
 #include "opt_lockdebug.h"
@@ -653,8 +653,7 @@
                 */
                if (exiting) {
                        KASSERT(p->p_nlwps > 1);
-                       cv_wait(&p->p_lwpcv, p->p_lock);
-                       error = EAGAIN;
+                       error = cv_timedwait(&p->p_lwpcv, p->p_lock, 1);
                        break;
                }
 
@@ -662,9 +661,6 @@
                 * If all other LWPs are waiting for exits or suspends
                 * and the supply of zombies and potential zombies is
                 * exhausted, then we are about to deadlock.
-                *
-                * If the process is exiting (and this LWP is not the one
-                * that is coordinating the exit) then bail out now.
                 */
                if ((p->p_sflag & PS_WEXIT) != 0 ||
                    p->p_nrlwps + p->p_nzlwps - p->p_ndlwps <= p->p_nlwpwait) {
@@ -839,7 +835,7 @@
        l2->l_inheritedprio = -1;
        l2->l_protectprio = -1;
        l2->l_auxprio = -1;
-       l2->l_flag = (l1->l_flag & (LW_WEXIT | LW_WREBOOT | LW_WCORE));
+       l2->l_flag = 0;
        l2->l_pflag = LP_MPSAFE;
        TAILQ_INIT(&l2->l_ld_locks);
        l2->l_psrefs = 0;
@@ -921,6 +917,11 @@
        } else
                l2->l_prflag = 0;
 
+       if (l1->l_proc == p2)
+               l2->l_flag |= (l1->l_flag & (LW_WEXIT | LW_WREBOOT | LW_WCORE));
+       else
+               l2->l_flag |= (l1->l_flag & LW_WREBOOT);
+
        l2->l_sigstk = *sigstk;
        l2->l_sigmask = *sigmask;
        TAILQ_INIT(&l2->l_sigpend.sp_info);