From: David Teigland <teigland@redhat.com>
Subject: [RHEL5.1 PATCH] dlm: schedule during recovery loops
Date: Tue, 25 Sep 2007 11:06:05 -0500
Bugzilla: 250464
Message-Id: <20070925160605.GD15893@redhat.com>
Changelog: [GFS2] dlm: schedule during recovery loops


bz 250464

Call schedule() in a bunch of places where the recovery code loops
through lists of locks.  The theory is that these lists become so
long that looping through them triggers the softlockup watchdog
(usually on ia64, doesn't seem to happen often on other arch's).
Will send the same patch upstream.


Index: linux-rhel51-2007-08-20/fs/dlm/lock.c
===================================================================
--- linux-rhel51-2007-08-20.orig/fs/dlm/lock.c
+++ linux-rhel51-2007-08-20/fs/dlm/lock.c
@@ -3997,6 +3997,7 @@ int dlm_recover_waiters_post(struct dlm_
 		unlock_rsb(r);
 		put_rsb(r);
 		dlm_put_lkb(lkb);
+		schedule();
 	}
 
 	return error;
Index: linux-rhel51-2007-08-20/fs/dlm/recover.c
===================================================================
--- linux-rhel51-2007-08-20.orig/fs/dlm/recover.c
+++ linux-rhel51-2007-08-20/fs/dlm/recover.c
@@ -533,6 +533,7 @@ int dlm_recover_locks(struct dlm_ls *ls)
 		}
 
 		count += r->res_recover_locks_count;
+		schedule();
 	}
 	up_read(&ls->ls_root_sem);
 
@@ -705,6 +706,7 @@ void dlm_recover_rsbs(struct dlm_ls *ls)
 		rsb_clear_flag(r, RSB_RECOVER_CONVERT);
 		rsb_clear_flag(r, RSB_NEW_MASTER2);
 		unlock_rsb(r);
+		schedule();
 	}
 	up_read(&ls->ls_root_sem);
 
@@ -732,6 +734,7 @@ int dlm_create_root_list(struct dlm_ls *
 			dlm_hold_rsb(r);
 		}
 		read_unlock(&ls->ls_rsbtbl[i].lock);
+		schedule();
 	}
  out:
 	up_write(&ls->ls_root_sem);
@@ -741,11 +744,15 @@ int dlm_create_root_list(struct dlm_ls *
 void dlm_release_root_list(struct dlm_ls *ls)
 {
 	struct dlm_rsb *r, *safe;
+	unsigned int count = 0;
 
 	down_write(&ls->ls_root_sem);
 	list_for_each_entry_safe(r, safe, &ls->ls_root_list, res_root_list) {
 		list_del_init(&r->res_root_list);
 		dlm_put_rsb(r);
+
+		if (!(++count % 100))
+			schedule();
 	}
 	up_write(&ls->ls_root_sem);
 }
@@ -763,6 +770,7 @@ void dlm_clear_toss_list(struct dlm_ls *
 			free_rsb(r);
 		}
 		write_unlock(&ls->ls_rsbtbl[i].lock);
+		schedule();
 	}
 }
 
Index: linux-rhel51-2007-08-20/fs/dlm/requestqueue.c
===================================================================
--- linux-rhel51-2007-08-20.orig/fs/dlm/requestqueue.c
+++ linux-rhel51-2007-08-20/fs/dlm/requestqueue.c
@@ -192,6 +192,7 @@ void dlm_purge_requestqueue(struct dlm_l
 			list_del(&e->list);
 			kfree(e);
 		}
+		schedule();
 	}
 	mutex_unlock(&ls->ls_requestqueue_mutex);
 }