[SSI] openssi/kernel/cluster/ssi/vproc dvp_pvpops.c, 1.41, 1.42 dvp_vpops.c, 1.41, 1.42 pproc_subr.c, 1.12, 1.13 rproc_cli_pproc.c, 1.23, 1.24 rproc_svr_pproc.c, 1.26, 1.27

Update of /cvsroot/ssic-linux/openssi/kernel/cluster/ssi/vproc
In directory fdv4jf1.ch3.sourceforge.com:/tmp/cvs-serv10005/kernel/cluster/ssi/vproc

Modified Files:
      Tag: OPENSSI-FC
	dvp_pvpops.c dvp_vpops.c pproc_subr.c rproc_cli_pproc.c 
	rproc_svr_pproc.c 
Log Message:
MOSIX:
- Fix race over elements in mosix_task struct. Use task_lock() to protect mosix_task->dctime, pages_i_bring, etc.
- Code clean up: choose(), consider(), mosix_calc_load().
- Fix release_migrations() using wrong lock for mosix_task->load.
- Remove unused pagetime, migpages in struct mosix_task.
- run_over_dirty_pages() to hold down_read(&mmap_sem) to avoid possible race. (#ifdef SSI_BALANCE_MEMORY)

VPROC:
- Use BKL to protect tty_old_pgrp in VProc context. (#ifdef PPROC_SETCTTY_SIGLOCK)


Index: dvp_vpops.c
===================================================================
RCS file: /cvsroot/ssic-linux/openssi/kernel/cluster/ssi/vproc/dvp_vpops.c,v
retrieving revision 1.41
retrieving revision 1.42
diff -u -d -r1.41 -r1.42
--- dvp_vpops.c	27 Oct 2009 03:18:29 -0000	1.41
+++ dvp_vpops.c	18 Nov 2009 06:16:53 -0000	1.42
@@ -681,7 +681,7 @@
 	if (ssi_roundrobin)
 		goto rr;
 #endif
-	consider(BALANCE, NULL, node);
+	consider(BALANCE, node);
 #endif /* CONFIG_MOSIX_LL */
 #ifdef CONFIG_SSI_RR_DEBUG
 rr:
@@ -2036,7 +2036,12 @@
  *		if the process is a pgrp ldr, pass it on to the members.
  *
  */
-/* Might be called with tty_sem held */
+/* Might be called with following locks in descending order:
+ * lock_kernel()
+ * OR
+ * lock_kernel()
+ * down(&tty_sem)
+ */
 int
 vpop_setctty(
 	struct vproc *v,	/* vproc of process getting the ctty  */
@@ -2607,7 +2612,7 @@
 	return error;
 }
 
-/* Called with tty_sem held */
+/* Called under BKL */
 struct tty_struct *
 ssi_release_tty(dev_t cttydev, clusternode_t cttynode, int exit)
 {

Index: rproc_cli_pproc.c
===================================================================
RCS file: /cvsroot/ssic-linux/openssi/kernel/cluster/ssi/vproc/rproc_cli_pproc.c,v
retrieving revision 1.23
retrieving revision 1.24
diff -u -d -r1.23 -r1.24
--- rproc_cli_pproc.c	27 Oct 2009 03:18:30 -0000	1.23
+++ rproc_cli_pproc.c	18 Nov 2009 06:16:53 -0000	1.24
@@ -160,6 +160,9 @@
 				return -ENOMEM;
 			}
 
+#ifdef PPROC_SETCTTY_SIGLOCK
+			lock_kernel(); /* protect tty_old_pgrp */
+#endif
 			spin_lock_irqsave(&t->sighand->siglock, flags);
 
 			error |= load_rvp_sigpending(sp, rsp);
@@ -169,13 +172,20 @@
 			if (!error)
 				break;
 			spin_unlock_irqrestore(&t->sighand->siglock, flags);
+#ifdef PPROC_SETCTTY_SIGLOCK
+			unlock_kernel();
+#endif
 
 			sigpending_remove_msg(rsp);
 			rsp = &comm_datap->comm_signal.rvp_ss_shared_pending;
 			sigpending_remove_msg(rsp);
 		}
-	} else
-		spin_lock_irqsave(&current->sighand->siglock, flags);
+	} else {
+#ifdef PPROC_SETCTTY_SIGLOCK
+		lock_kernel(); /* protect tty_old_pgrp */
+#endif
+		spin_lock_irqsave(&t->sighand->siglock, flags);
+	}
 
 	comm_datap->comm_signal.rvp_ss_flags = t->signal->flags;
 	comm_datap->comm_signal.rvp_ss_tty_old_pgrp = t->signal->tty_old_pgrp;
@@ -201,6 +211,9 @@
 
 	spin_unlock_irqrestore(&t->sighand->siglock, flags);
 
+#ifdef PPROC_SETCTTY_SIGLOCK
+	unlock_kernel();
+#endif
 	return 0;
 }
 
@@ -654,13 +667,16 @@
 		t->node_context : this_node;
 #ifdef CONFIG_MOSIX_LL
 	/* load leveling information */
+	/* SSI_XXX: skipped task_rq_lock for mosix.dflags */
+	task_lock(t);
 	comm_datap->comm_dflags = (t->mosix.dflags & ~DPAGEIN);
 	comm_datap->comm_stay = t->mosix.stay;
-	comm_datap->comm_dctime = t->mosix.dctime;
-	comm_datap->comm_pagetime = t->mosix.pagetime;
-	comm_datap->comm_pages_i_bring = t->mosix.pages_i_bring;
+	/* comm_datap->comm_pagetime = t->mosix.pagetime; */
 	comm_datap->comm_last_consider = t->mosix.last_consider;
 	comm_datap->comm_last_mconsider = t->mosix.last_mconsider;
+	comm_datap->comm_pages_i_bring = t->mosix.pages_i_bring;
+	comm_datap->comm_dctime = t->mosix.dctime;
+	task_unlock(t);
 #endif
 out:
 

Index: rproc_svr_pproc.c
===================================================================
RCS file: /cvsroot/ssic-linux/openssi/kernel/cluster/ssi/vproc/rproc_svr_pproc.c,v
retrieving revision 1.26
retrieving revision 1.27
diff -u -d -r1.26 -r1.27
--- rproc_svr_pproc.c	27 Oct 2009 03:18:30 -0000	1.26
+++ rproc_svr_pproc.c	18 Nov 2009 06:16:53 -0000	1.27
@@ -117,6 +117,9 @@
 				return -ENOMEM;
 			}
 			locked = 1;
+#ifdef PPROC_SETCTTY_SIGLOCK
+			lock_kernel(); /* protect tty_old_pgrp */
+#endif
 			spin_lock_irqsave(&t->sighand->siglock, flags);
 			pp = &t->pending;
 			flush_sigqueue(pp);
@@ -133,6 +136,9 @@
 		}
 		t->signal->flags = rsigp->rvp_ss_flags;
 		t->signal->tty_old_pgrp = rsigp->rvp_ss_tty_old_pgrp;
+#ifdef PPROC_SETCTTY_SIGLOCK
+		unlock_kernel();
+#endif
 		t->signal->leader = rsigp->rvp_ss_leader;
 		t->signal->cttydev = rsigp->rvp_ss_cttydev;
 		t->signal->cttynode = rsigp->rvp_ss_cttynode;
@@ -517,13 +523,15 @@
 	t->node_context = comm_datap->comm_node_context;
 
 #ifdef CONFIG_MOSIX_LL
+	task_lock(t);
 	t->mosix.dflags = comm_datap->comm_dflags;
 	t->mosix.stay = comm_datap->comm_stay;
-	t->mosix.pagetime = comm_datap->comm_pagetime;
+	/* t->mosix.pagetime = comm_datap->comm_pagetime; */
 	t->mosix.last_consider = comm_datap->comm_last_consider;
 	t->mosix.last_mconsider = comm_datap->comm_last_mconsider;
 	t->mosix.pages_i_bring = comm_datap->comm_pages_i_bring;
 	t->mosix.dctime = comm_datap->comm_dctime;
+	task_unlock(t);
 #endif
 out:
 	return error;

Index: pproc_subr.c
===================================================================
RCS file: /cvsroot/ssic-linux/openssi/kernel/cluster/ssi/vproc/pproc_subr.c,v
retrieving revision 1.12
retrieving revision 1.13
diff -u -d -r1.12 -r1.13
--- pproc_subr.c	27 Oct 2009 03:18:30 -0000	1.12
+++ pproc_subr.c	18 Nov 2009 06:16:53 -0000	1.13
@@ -126,6 +126,8 @@
 	 * tasklist_lock	(pproc_setctty)
 	 * task_lock		(pproc_setctty)
 	 */
+#else
+	lock_kernel(); /* protect tty_old_pgrp. see disassociate_ctty() */
 #endif
 	read_lock(&tasklist_lock);
 	if (p->signal) {
@@ -152,6 +154,9 @@
 		task_unlock(p);
 	}
 	read_unlock(&tasklist_lock);
+#ifdef PPROC_SETCTTY_SIGLOCK
+	unlock_kernel();
+#endif
 
 	return 0;
 }
@@ -287,6 +292,7 @@
  *	This function is called when the controlling process exits.
  *	The process is already single threaded at this point.
  */
+/* Might be called under BKL */
 int
 pps_release_ctty(dev_t cttydev, int exit, pid_t *pgidp)
 {

Index: dvp_pvpops.c
===================================================================
RCS file: /cvsroot/ssic-linux/openssi/kernel/cluster/ssi/vproc/dvp_pvpops.c,v
retrieving revision 1.41
retrieving revision 1.42
diff -u -d -r1.41 -r1.42
--- dvp_pvpops.c	27 Oct 2009 03:18:29 -0000	1.41
+++ dvp_pvpops.c	18 Nov 2009 06:16:53 -0000	1.42
@@ -3368,20 +3368,11 @@
 						(flags & VCTTY_CLEARCTTY)) {
 		PVPOP_SIGPROC(v, SIGHUP, SIGCONT, 0, VSIG_INTERNAL, NULL);
 #ifdef VPROC_HOLD_ZERO_GET_TASK
-		if (PV_IS_ALIVE(pvp)) {
-			task_t *p = pvp->pvp_pproc;
-#ifdef PPROC_SETCTTY_SIGLOCK
-			task_lock(p); /* see pproc_setctty() */
-#endif
-			p->signal->tty_old_pgrp = pgid;
-#ifdef PPROC_SETCTTY_SIGLOCK
-			task_unlock(p);
-#endif
-		}
+		if (PV_IS_ALIVE(pvp))
 #else
 		if (PVP(v)->pvp_pproc != NULL)
-			PVP(v)->pvp_pproc->signal->tty_old_pgrp = pgid;
 #endif
+			PVP(v)->pvp_pproc->signal->tty_old_pgrp = pgid;
 	}
 
 	/*


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